ORCID Profile
0000-0002-5305-9458
Current Organisation
Xi'an Jiaotong University
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Palaeoclimatology | Physical Geography and Environmental Geoscience | Quaternary Environments | Atmospheric Sciences | Environmental Impact Assessment | Natural Resource Management | Archaeological Science | Climatology (Incl. Palaeoclimatology) | Climate Change Processes
ANZSRC Socio-Economic Objective (SEO)
Climate variability | Effects of Climate Change and Variability on Australia (excl. Social Impacts) | Land and water management | Natural Hazards in Coastal and Estuarine Environments | Social Impacts of Climate Change and Variability | Climate and Climate Change not elsewhere classified |
Related Links
Publications
A stalagmite record of abrupt climate change and possible Westerlies-derived atmospheric precipitation during the Penultimate Glacial Maximum in northern China
Publisher: Elsevier BV
Date: 2014
Interannual oxygen isotope variability in Indian summer monsoon precipitation reflects changes in moisture sources
Publisher: Springer Science and Business Media LLC
Date: 20-05-2021
DOI: 10.1038/S43247-021-00165-Z
Abstract: The primary influences on the spatio-temporal variability of oxygen isotope compositions in precipitation over the Indian summer monsoon domain are inadequately constrained by the limited observational record. Consequently, the climatic significance of isotopic signatures of precipitation preserved in proxy archives from the region remains unclear. Here we present simulations with an isotope-enabled climate model (IsoGSM2) with the moisture-tagging capability to investigate the role of relative contributions of moisture from oceanic and terrestrial sources to the interannual variability in oxygen isotope composition in summer monsoon rainfall. During weak monsoon years, the moisture contribution from the Arabian Sea dominates precipitation over the Indian subcontinent while the remote oceanic and terrestrial sources have a greater influence during strong monsoon years. We suggest that changes in monsoon circulation, moisture source, and precipitation intensity are interrelated and that speleothem oxygen isotope records from the region can potentially help reconstruct interannual to decadal monsoon rainfall variability.
Virtual reconstruction of the Palaeolithic landscape in Santimamine cave (Bizkaia, Spain)
Publisher: Elsevier BV
Date: 12-2023
Intensity of Th and Pa scavenging partitioned by particle chemistry in the North Atlantic Ocean
Publisher: Elsevier BV
Date: 03-2015
THE CONTRIBUTION OF CONDENSATION-CORROSION IN THE MORPHOLOGICAL EVOLUTION OF CAVES IN SEMI-ARID REGIONS: PRELIMINARY INVESTIGATIONS IN THE KYRENIA RANGE, CYPRUS
Publisher: The Research Center of the Slovenian Academy of Sciences and Arts / Znanstvenoraziskovalni center Slovenske akademije znanosti in umetnosti (ZRC SAZU)
Date: 06-03-2019
Textural and carbon isotopic evidence of monsoonal changes recorded in a composite-type speleothem from Korea since MIS 5a
Publisher: Cambridge University Press (CUP)
Date: 07-2010
DOI: 10.1016/J.YQRES.2010.04.005
Abstract: Textural and stable isotopic records of a composite-type speleothem from Gwaneum Cave in the eastern part of the Korean peninsula show prominent paleoenvironmental changes since MIS (marine oxygen isotope stage) 5a. Based on 230 Th/ 234 U dating, the speleothem experienced growth from 90.9 ± 6.5 ka to 1.2 ± 0.5 ka with several hiatuses. Four growth phases (A, B, C and D) are recognized based on speleothem type and texture. Very irregular and laterally discontinuous growth laminae in Phases B and C indicate that the cave coralloids grew over the stalagmite (Phase A) when the supply of dripping water became limited. Variations within the δ 13 C time series of Phase A are interpreted as responses to millennial-scale fluctuations of the East Asian monsoon intensity during MIS 5a. The monsoonal interpretation is based on the idea that δ 13 C values reflect the isotopic composition of soil-derived CO 2 , which, in turn, should relate to monsoon-driven changes in terrestrial productivity above the cave during the MIS 5a. Our reconstruction reveals that the significant monsoonal changes on the Korean peninsula occurred in conjunction with changes in sea level and/or oceanic circulations during the transition period from MIS 5a to MIS 4.
High-resolution Holocene South American monsoon history recorded by a speleothem from Botuverá Cave, Brazil
Publisher: Elsevier BV
Date: 09-2016
A continuous 3000-year precipitation record of ENSO vari-ability during LGM from a stalagmite in Nanjing
Publisher: Science China Press., Co. Ltd.
Date: 2003
DOI: 10.1360/03TB9102
Late Holocene monsoon precipitation changes in southern China and their linkage to Northern Hemisphere temperature
Publisher: Elsevier BV
Date: 03-2020
Abrupt monsoonal shifts over the precessional cycles documented in Yongxing Cave in China during the antepenultimate glacial period
Publisher: Springer Science and Business Media LLC
Date: 03-2018
Paleoclimate in continental northwestern Europe during the Eemian and early Weichselian (125–97 ka): insights from a Belgian speleothem
Publisher: Copernicus GmbH
Date: 05-07-2016
Abstract: Abstract. The last interglacial serves as an excellent time interval for studying climate dynamics during past warm periods. Speleothems have been successfully used for reconstructing the paleoclimate of last interglacial continental Europe. However, all previously investigated speleothems are restricted to southern Europe or the Alps, leaving large parts of northwestern Europe undocumented. To better understand regional climate changes over the past, a larger spatial coverage of European last interglacial continental records is essential, and speleothems, because of their ability to obtain excellent chronologies, can provide a major contribution. Here, we present new, high-resolution data from a stalagmite (Han-9) obtained from the Han-sur-Lesse Cave in Belgium. Han-9 formed between 125.3 and ∼ 97 ka, with interruptions of growth occurring at 117.3–112.9 and 106.6–103.6 ka. The speleothem was investigated for its growth, morphology and stable isotope (δ13C and δ18O) composition. The speleothem started growing relatively late within the last interglacial, at 125.3 ka, as other European continental archives suggest that Eemian optimum conditions were already present during that time. It appears that the initiation of Han-9 growth is caused by an increase in moisture availability, linked to wetter conditions around 125.3 ka. The δ13C and δ18O proxies indicate a period of relatively stable conditions after 125.3 ka however, at 120 ka the speleothem δ18O registered the first signs of regionally changing climate conditions, being a modification of ocean source δ18O linked to an increase in ice volume towards the Marine Isotope Stage (MIS) 5e–5d transition. At 117.5 ka, drastic vegetation changes are recorded by Han-9 δ13C immediately followed by a cessation of speleothem growth at 117.3 ka, suggesting a transition to significantly dryer conditions. The Han-9 record covering the early Weichselian displays larger litudes in both isotope proxies and changes in stalagmite morphology, evidencing increased variability compared to the Eemian. Stadials that appear to be analogous to those in Greenland are recognized in Han-9, and the chronology is consistent with other European (speleothem) records. Greenland Stadial 25 is reflected as a cold/dry period within Han-9 stable isotope proxies, and the second interruption in speleothem growth occurs simultaneously with Greenland Stadial 24.
U–Th systematics and 230Th ages of carbonate chimneys at the Lost City Hydrothermal Field
Publisher: Elsevier BV
Date: 04-2011
An extended and higher-resolution record of climate and land use from stalagmite MC01 from Macal Chasm, Belize, revealing connections between major dry events, overall climate variability, and Maya so
Publisher: Elsevier BV
Date: 10-2016
Long-term trend and abrupt events of the Holocene Asian monsoon inferred from a stalagmite δ10O record from Shennongjia in Central China
Publisher: Springer Science and Business Media LLC
Date: 2006
Holocene and deglaciation hydroclimate changes in northern China as inferred from stalagmite growth frequency
Publisher: Elsevier BV
Date: 12-2020
Sequence of mammalian fossils, including hominoid teeth, from the Bubing Basin caves, South China
Publisher: Elsevier BV
Date: 04-2007
DOI: 10.1016/J.JHEVOL.2006.10.003
Abstract: A Plio-Pleistocene to Holocene faunal sequence has been recovered from four carefully excavated caves in the Bubing Basin, adjacent to the larger Bose Basin of South China. The caves vary in elevation we suggest that the higher caves were formed and filled with sediments prior to the lower caves. The highest deposits, which are from Mohui Cave, contain hominoid teeth and other fossilized remains of mammalian taxa most similar to late Pliocene and early Pleistocene faunas. Wuyun Cave ( approximately 50m lower in elevation than Mohui) contains a late middle Pleistocene fauna, which is supported by U-series age constraints from 350 to 200ka. Lower Pubu Cave ( approximately 23m below Wuyun) is assigned to the late Pleistocene, while the Cunkong Cave (the lowest, approximately 2m lower elevation than Lower Pubu) preserves a Holocene fauna. The four faunal assemblages indicate species-level changes in Ailuropoda, Stegodon, and Sus, the appearance of Elephas, the local disappearance of Stegodon, and the migration of Equus hemionus to South China. These initial results of our work call into question the continued value of the Stegodon/Ailuropoda Fauna, a category long used to characterize the Pleistocene faunas of South China. Excavation of karstic caves of varying elevation within the basins of South China holds promise for defining local sequences of mammalian fossils that can be used to investigate faunal variations related to climate change, biogeographic events, and evolutionary change over the past two million years. Stable isotopic analysis of a small s le of mammalian teeth from Bubing Basin caves is consistent with 100% C(3) vegetation in the Bubing/Bose region, with certain delta(13)C values consistent with a canopied woodland or forest. A preliminary assessment of the hominoid teeth indicates the presence of erse molar and premolar morphologies including dental remains of Gigantopithecus blacki and a s le with similarities to the teeth reported from Longgupo.
Role of the Summer Monsoon Variability in the Collapse of the Ming Dynasty: Evidences From Speleothem Records
Publisher: American Geophysical Union (AGU)
Date: 06-06-2021
DOI: 10.1029/2021GL093071
Abstract: Climatic changes have played an important role in societal reorganizations. Particularly, the late 16th and early 17th century coincided with severely cold condition, extremely weak summer monsoon and widespread population decline in China. Here we present new speleothem oxygen isotope records across North and South China, which in concert with historical documents, allow us to characterize the “Late Ming Weak Monsoon Periods” (LMWMP) at an unprecedented annual temporal resolution. Our analysis suggests that as a weak summer monsoon event not seen for nearly 500 years in China, the LMWMP spatiotemporally coincided with the late Ming Dynasty peasant uprising (1627–1658 CE), and thus the transition from Ming to Qing Dynasty. This suggests a plausible role of climate change in shaping the important chapters of the Chinese history. In addition, both speleothem and historical documents reveal that the LMWMP appears to be a north to south time‐transgressive event on decadal‐timescale.
The 5400 a BP extreme weakening event of the Asian summer monsoon and cultural evolution
Publisher: Springer Science and Business Media LLC
Date: 17-03-2017
Modern stalagmite oxygen isotopic composition and its implications of climatic change from a high-elevation cave in the eastern Qinghai-Tibet Plateau over the past 50 years
Publisher: Springer Science and Business Media LLC
Date: 05-2007
Cyclic sedimentation in Brazilian caves: Mechanisms and palaeoenvironmental significance
Publisher: Elsevier BV
Date: 05-2009
Evaluating the timing and structure of the 4.2 ka event in the Indian summer monsoon domain from an annually resolved speleothem record from Northeast India
Publisher: Copernicus GmbH
Date: 30-11-2018
Abstract: Abstract. A large array of proxy records suggests that the “4.2 ka event” marks an approximately 300-year long period (∼3.9 to 4.2 ka) of major climate change across the globe. However, the climatic manifestation of this event, including its onset, duration, and termination, remains less clear in the Indian summer monsoon (ISM) domain. Here, we present new oxygen isotope (δ18O) data from a pair of speleothems (ML.1 and ML.2) from Mawmluh Cave, Meghalaya, India, that provide a high-resolution record of ISM variability during a period (∼3.78 and 4.44 ka) that fully encompasses the 4.2 ka event. The sub-annually to annually resolved ML.1 δ18O record is constrained by 18 230Th dates with an average dating error of ±13 years (2σ) and a resolution of ∼40 years, which allows us to characterize the ISM variability with unprecedented detail. The inferred pattern of ISM variability during the period contemporaneous with the 4.2 ka event shares broad similarities and key differences with the previous reconstructions of ISM from the Mawmluh Cave and other proxy records from the region. Our data suggest that the ISM intensity, in the context of the length of our record, abruptly decreased at ∼4.0 ka (∼±13 years), marking the onset of a multi-centennial period of relatively reduced ISM, which was punctuated by at least two multi-decadal droughts between ∼3.9 and 4.0 ka. The latter stands out in contrast with some previous proxy reconstructions of the ISM, in which the 4.2 ka event has been depicted as a singular multi-centennial drought.
A high‐resolution speleothem proxy record of the Late Glacial in the European Alps: extending the NALPS19 record until the beginning of the Holocene
Publisher: Wiley
Date: 22-10-2020
DOI: 10.1002/JQS.3255
Orbital- and millennial-scale variability of the Asian monsoon during MIS8 from Sanbao Cave at Mount Shennongjia, central China
Publisher: Springer Science and Business Media LLC
Date: 10-11-2009
Panigarh cave stalagmite evidence of climate change in the Indian Central Himalaya since AD 1256: Monsoon breaks and winter southern jet depressions
Publisher: Elsevier BV
Date: 09-2015
Variability of stalagmite-inferred Indian monsoon precipitation over the past 252,000 y
Publisher: Proceedings of the National Academy of Sciences
Date: 23-02-2015
Abstract: This paper presents a new long speleothem δ 18 O time series from Xiaobailong cave in southwest China that characterizes changes in a major branch of Indian summer monsoon precipitation over the last 252 kyrs. This record shows not only 23-kyr precessional cycles punctuated by prominent millennial-scale weak monsoon events synchronous with Heinrich events in the North Atlantic, but also clear glacial–interglacial variations that are consistent with marine records but different from the cave records in East China. The speleothem records of Xiaobailong and other caves in East China show that the relationship between the Indian and the East Asian summer monsoon precipitation is not invariant, but rather varies on different timescales depending on the nature and magnitude of the climate forcing.
Correction: Corrigendum: The Asian monsoon over the past 640,000 years and ice age terminations
Publisher: Springer Science and Business Media LLC
Date: 23-11-2016
DOI: 10.1038/NATURE20585
Role of climate in the rise and fall of the Neo-Assyrian Empire
Publisher: American Association for the Advancement of Science (AAAS)
Date: 11-2019
Abstract: Climate change played an important causal role in the expansion and collapse of the Neo-Assyrian Empire.
Ancient DNA and multimethod dating confirm the late arrival of anatomically modern humans in southern China
Publisher: Proceedings of the National Academy of Sciences
Date: 08-02-2021
Abstract: Genetic studies show the founders of all living non-African populations expanded from Africa ca. 65 to 45 ka. This “late dispersal” model has been challenged by the discovery of isolated AMHs at caves in southern China suggested as early as ca. 120 ka. We assessed the age of early AMH fossils from five caves in this region using ancient DNA analysis and a multimethod geological dating strategy. We found they were much younger than previously suggested, with some remains dating to the Holocene owing to the complex depositional history at these subtropical caves. Current evidence shows AMHs settled southern China within the timeframe set by molecular data of less than ca. 50 to 45 ka and no earlier.
Termination-II interstadial/stadial climate change recorded in two stalagmites from the north European Alps
Publisher: Elsevier BV
Date: 11-2015
Hydroclimate variability of the northwestern Amazon Basin near the Andean foothills of Peru related to the South American Monsoon System during the last 1600 years
Publisher: Copernicus GmbH
Date: 19-11-2014
Abstract: Abstract. In this paper we explore a speleothem δ18O record from Palestina cave, northwestern Peru, at a site on the eastern side of the Andes cordillera, in the upper Amazon Basin. The δ18O record is interpreted as a proxy for South American Summer Monsoon (SASM) intensity and allows the reconstruction of its variability during the last 1600 years. Two periods of anomalous changes in the climate mean state corresponding to the Medieval Climate Anomaly (MCA) and the Little Ice Age (LIA) periods identified in the Northern Hemisphere are recognized in the record, in which decreased and increased SASM activity, respectively, have been documented. Variations in SASM activity between the MCA and the LIA seem to be larger over the northern part of the continent, suggesting a latitudinal dependence of the MCA footprint. Our results, based on time series, composite and wavelet analyses, suggest that the Atlantic Multidecadal Oscillation (AMO) plays an relevant role for SASM modulation on multidecadal scales (∼65 years), especially during dry periods such as the MCA. Composite analyses, applied to evaluate the influence of the AMO on the Palestina cave δ18O and other δ18O-derived SASM reconstructions, allow insight into the spatial footprints of the AMO over tropical South America and highlight differences between records during key studied periods. This work also reveals that replicating regional climate signals from different sites, and using different proxies is absolutely essential for a comprehensive understanding of past changes in SASM activity.
Holocene Monsoon Change and Abrupt Events on the Western Chinese Loess Plateau as Revealed by Accurately Dated Stalagmites
Publisher: American Geophysical Union (AGU)
Date: 05-11-2020
DOI: 10.1029/2020GL090273
Abstract: Here we present, to date, the highest‐resolved (~5 years) and most precisely dated Holocene monsoon climate reconstruction for the western Chinese Loess Plateau based on five replicated stalagmite δ 18 O records from Wuya Cave, eastern Gansu, China. Our record suggests the wettest period occurred between 10,500 and 6,600 a BP in this region. After this period, the litude of Asian summer monsoon decadal‐scale variability progressively increased likely in response to increasing ENSO frequency since the middle Holocene. Our study reveals similar asymmetric centennial‐scale double‐plunging structures of the 8.2, 5.5, and 2.8 ka events in the western Chinese Loess Plateau, suggesting a possible role of solar activity whose impact was lified around 8.2 ka BP by the meltwater flood. In contrast, the 4.2 ka event exhibit gradually declining monsoon rainfall with centennial‐ to decadal‐scale fluctuations.
A 500-year seasonally resolved δ<sup>18</sup>O and δ<sup>13</sup>C, layer thickness and calcite aspect record from a speleothem deposited in the
Publisher: Copernicus GmbH
Date: 06-2015
Abstract: Abstract. Speleothem δ18O and δ13C signals enable climate reconstructions at high resolution. However, scarce decadal and seasonally resolved speleothem records are often difficult to interpret in terms of climate due to the multitude of factors that affect the proxy signals. In this paper, a fast-growing (up to 2 mm yr−1) seasonally laminated speleothem from the Han-sur-Lesse cave (Belgium) is analyzed for its δ18O and δ13C values, layer thickness and changes in calcite aspect. The studied record covers the period between AD 2001 and 1479 as indicated by layer counting and confirmed by 20 U / Th ages. The Proserpine proxies are seasonally biased and document drier (and colder) winters on multidecadal scales. Higher δ13C signals reflect increased prior calcite precipitation (PCP) and lower soil activity during drier (and colder) winters. Thinner layers and darker calcite relate to slower growth and exist during drier (and colder) winter periods. Exceptionally dry (and cold) winter periods occur from 1565 to 1610, at 1730, from 1770 to 1800, from 1810 to 1860, and from 1880 to 1895 and correspond to exceptionally cold periods in historical and instrumental records as well as European winter temperature reconstructions. More relative climate variations, during which the four measured proxies vary independently and display lower litude variations, occur between 1479 and 1565, between 1610 and 1730, and between 1730 and 1770. The winters during the first and last periods are interpreted as relatively wetter (and warmer) and correspond to warmer periods in historical data and in winter temperature reconstructions in Europe. The winters in the period between 1610 and 1730 are interpreted as relatively drier (and cooler) and correspond to generally colder conditions in Europe. Interpretation of the seasonal variations in δ18O and δ13C signals differs from that on a decadal and multidecadal scale. Seasonal δ18O variations reflect cave air temperature variations and suggest a 2.5 °C seasonality in cave air temperature during the two relatively wetter (and warmer) winter periods (1479–1565 and 1730–1770), which corresponds to the cave air temperature seasonality observed today. Between 1610 and 1730, the δ18O values suggest a 1.5 °C seasonality in cave air temperature, indicating colder summer temperatures during this drier (and cooler) interval. The δ13C seasonality is driven by PCP and suggests generally lower PCP seasonal effects between 1479 and 1810 compared to today. A short interval of increased PCP seasonality occurs between 1600 and 1660, and reflects increased PCP in summer due to decreased winter recharge.
Central Equatorial Pacific Warming and Freshening in the Twentieth Century: Insights From a Coral Ensemble Approach
Publisher: American Geophysical Union (AGU)
Date: 29-12-2021
DOI: 10.1029/2021GL094051
Abstract: The tropical Pacific influences climate patterns across the globe, yet robust constraints on decadal to centennial‐scale climate variations are difficult to extract from sparse instrumental observations in this region. Oxygen isotope (δ 18 O) records from long‐lived corals enable the quantitative reconstruction of tropical Pacific climate variability and trends over the twentieth century and beyond, but such corals are exceedingly rare. Here, we use multiple short coral δ 18 O records to create a coral ‘ensemble’ reconstruction of twentieth century climate in the central tropical Pacific. Ten U/Th‐dated fossil coral δ 18 O records from Kiritimati Island (2°N, 157°W) span 1891 CE to 2006 CE, with the younger s les enabling quantitative comparison to a large ensemble of modern coral records and instrumental sea surface temperature. A composite record constructed of modern and fossil Kiritimati coral δ 18 O records shows a shift toward warmer and fresher conditions from 1970 CE onward, consistent with previously published records in this region.
Climatic and in-cave influences on δ18O and δ13C in a stalagmite from northeastern India through the last deglaciation
Publisher: Cambridge University Press (CUP)
Date: 21-09-2017
DOI: 10.1017/QUA.2017.72
Abstract: Northeastern (NE) India experiences extraordinarily pronounced seasonal climate, governed by the Indian summer monsoon (ISM). The vulnerability of this region to floods and droughts calls for detailed and highly resolved paleoclimate reconstructions to assess the recurrence rate and driving factors of ISM changes. We use stable oxygen and carbon isotope ratios (δ 18 O and δ 13 C) from stalagmite MAW-6 from Mawmluh Cave to infer climate and environmental conditions in NE India over the last deglaciation (16–6ka). We interpret stalagmite δ 18 O as reflecting ISM strength, whereas δ 13 C appears to be driven by local hydroclimate conditions. Pronounced shifts in ISM strength over the deglaciation are apparent from the δ 18 O record, similarly to other records from monsoonal Asia. The ISM is weaker during the late glacial (LG) period and the Younger Dryas, and stronger during the Bølling-Allerød and Holocene. Local conditions inferred from the δ 13 C record appear to have changed less substantially over time, possibly related to the masking effect of changing precipitation seasonality. Time series analysis of the δ 18 O record reveals more chaotic conditions during the late glacial and higher predictability during the Holocene, likely related to the strengthening of the seasonal recurrence of the ISM with the onset of the Holocene.
Testing the annual nature of speleothem banding
Publisher: Springer Science and Business Media LLC
Date: 16-09-2013
DOI: 10.1038/SREP02633
Abstract: Speleothem laminae have been postulated to form annually and this lamina-chronology is widely applied to high-resolution modern and past climate reconstructions. However, this argument has not been directly supported by high resolution dating methods. Here we present contemporary single-lamina 230 Th dating techniques with 2σ precision as good as ±0.5 yr on a laminated stalagmite with density couplets from Xianren Cave, China, that covers the last 300 years. We find that the layers do not always deposit annually. Annual bands can be under- or over-counted by several years during different multi-decadal intervals. The irregular formation of missing and false bands in this ex le indicates that the assumption of annual speleothem laminae in a climate reconstruction should be approached carefully without a robust absolute-dated chronology.
How Far North Did the African Monsoon Fringe Expand During the African Humid Period? Insights From Southwest Moroccan Speleothems
Publisher: American Geophysical Union (AGU)
Date: 13-12-2019
DOI: 10.1029/2019GL084879
Mass spectrometric U-series dating of Laibin hominid site in Guangxi, southern China
Publisher: Elsevier BV
Date: 12-2007
Long-term changes in precipitation recorded by magnetic minerals in speleothems
Publisher: Geological Society of America
Date: 07-2015
DOI: 10.1130/G36695.1
Publisher Correction: Multi-decadal to centennial hydro-climate variability and linkage to solar forcing in the Western Mediterranean during the last 1000 years
Publisher: Springer Science and Business Media LLC
Date: 16-07-2020
DOI: 10.1038/S41598-020-69147-Z
Abstract: An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Holocene flood frequency reconstruction from speleothems in northern Spain
Publisher: Elsevier BV
Date: 11-2015
The Y. D. and climate abrupt events in the early and middle Holocene: Stalagmite oxygen isotope record from Maolan, Guizhou, China
Publisher: Springer Science and Business Media LLC
Date: 04-2005
DOI: 10.1360/02YD0461
From cave geomorphology to Palaeolithic human behaviour: speleogenesis, palaeoenvironmental changes and archaeological insight in the Atxurra‐Armiña cave (northern Iberian Peninsula)
Publisher: Wiley
Date: 15-06-2020
DOI: 10.1002/JQS.3225
Stalagmite multi-proxy evidence of wet and dry intervals in northeastern Namibia: Linkage to latitudinal shifts of the Inter-Tropical Convergence Zone and changing solar activity from AD 1400 to 1950
Publisher: SAGE Publications
Date: 28-07-2016
Abstract: Multiple proxies using variation in δ 18 O, δ 13 C, mineralogy, and petrography in a newly generated high-resolution record of Stalagmite DP1 from Dante Cave indicate a linkage between changes in hydroclimate in northeastern Namibia and changes in solar activity and changes in global temperatures. The record suggests that during solar minima and globally cooler conditions (ca. 1660–1710 and ca. 1790–1830), wetter periods (reflecting longer summer seasons) in northeastern Namibia were linked to advances of the Inter-Tropical Convergence Zone (ITCZ) and the Inter-Ocean Convergence Zone (IOCZ) southwestward. A slight southward push of the Angola–Benguela Front (ABF) during such intervals could also be expected, bringing more rainfall inland. On the other hand, drier and warmer periods in northeastern Namibia, inferred from the increasing δ 18 O trend in Stalagmite DP1 after AD 1715, coincide with globally warmer conditions, and thus a northeastward migration of the ITCZ, specifically with more warming of the Northern Hemisphere (NH). This finding agrees with reducing precipitation observed in the summer rainfall zone of southern Africa since ca. 1900. Therefore, predictions of warming in high-latitude regions of the NH in the next century should suggest that the presently semi-arid climate of northern Namibia may become even drier.
High-resolution stalagmite δ 13C record of soil processes from southwestern China during the early MIS 3
Publisher: Springer Science and Business Media LLC
Date: 21-09-2012
Oxygen isotope precipitation anomaly in the North Atlantic region during the 8.2 ka event
Publisher: Geological Society of America
Date: 12-2009
DOI: 10.1130/G30393A.1
Climate variations of Central Asia on orbital to millennial timescales
Publisher: Springer Science and Business Media LLC
Date: 11-11-2016
DOI: 10.1038/SREP36975
Abstract: The extent to which climate variability in Central Asia is causally linked to large-scale changes in the Asian monsoon on varying timescales remains a longstanding question. Here we present precisely dated high-resolution speleothem oxygen-carbon isotope and trace element records of Central Asia’s hydroclimate variability from Tonnel’naya cave, Uzbekistan and Kesang cave, western China. On orbital timescales, the supra-regional climate variance, inferred from our oxygen isotope records, exhibits a precessional rhythm, punctuated by millennial-scale abrupt climate events, suggesting a close coupling with the Asian monsoon. However, the local hydroclimatic variability at both cave sites, inferred from carbon isotope and trace element records, shows climate variations that are distinctly different from their supra-regional modes. Particularly, hydroclimatic changes in both Tonnel’naya and Kesang areas during the Holocene lag behind the supra-regional climate variability by several thousand years. These observations may reconcile the apparent out-of-phase hydroclimatic variability, inferred from the Holocene lake proxy records, between Westerly Central Asia and Monsoon Asia.
Quaternary depositional facies in cave entrances and their relation to landscape evolution: The example of Cuvieri Cave, eastern Brazil
Publisher: Elsevier BV
Date: 10-2017
Little Ice Age climate changes in Southwest China from a stalagmite δ18O record
Publisher: Elsevier BV
Date: 2021
Ecosystem and paleohydrological response to Quaternary climate change in the Bonneville Basin, Utah
Publisher: Elsevier BV
Date: 05-2005
High-elevation Tibetan Plateau before India–Eurasia collision recorded by triple oxygen isotopes
Publisher: Springer Science and Business Media LLC
Date: 10-08-2023
Evidence for 800years of North Atlantic multi-decadal variability from a Puerto Rican speleothem
Publisher: Elsevier BV
Date: 08-2011
Large variations of oxygen isotopes in precipitation over south-central Tibet during Marine Isotope Stage 5
Publisher: Geological Society of America
Date: 03-2010
DOI: 10.1130/G30306.1
Hydrological change in Southern Europe responding to increasing North Atlantic overturning during Greenland Stadial 1
Publisher: Proceedings of the National Academy of Sciences
Date: 11-05-2015
Abstract: This study presents robust evidence of two hydrological phases within the Greenland Stadial 1 (GS-1) cold event (12.8−11.7 ka B.P.) in Southern Europe. We present a well-dated high-resolution speleothem record (Seso Cave, Central Pyrenees) where temperature and hydrological signals are independently reconstructed. Detailed interpretation of stable isotopes and trace elements allow characterizing a first dry period followed, after 12,500 y before 2000 A.D., by more humid conditions. Our findings point to the resumption of the Atlantic overturning circulation as the main mechanism behind the hydrological response in Europe during this mid–GS-1 transition. The second phase, cold in Greenland but humid in Western Europe, represents a new paradigm in the well-established model of dry, cold stadials during the last glacial period.
High precise dating on the variation of the Asian summer monsoon since 37 ka BP
Publisher: Springer Science and Business Media LLC
Date: 30-04-2021
DOI: 10.1038/S41598-021-88597-7
Abstract: Comprehensive comparison of paleoclimate change based on records constrained by precise chronology and high-resolution is essential to explore the correlation and interaction within earth climate systems. Here, we propose a new stalagmite-based multidecadal resolved Asian summer monsoon (ASM) record spanning the past thirty-seven thousand years (ka BP, before ad 1950) from Furong Cave, southwestern China. This record is consistent with the published Chinese stalagmite sequences and shows that the dominant controls of the ASM dynamics include not only insolation and solar activity but also suborbital-scale hydroclimate events in the high latitudes of the northern hemisphere, such as the Heinrich events, Bølling-Allerød (BA), and Younger Dryas (YD). Benefit from the unprecedented accurate chronology, the timings of these events are precisely dated, with uncertainties of, at most, 40 years (2σ). The onset of the weak ASM during the YD began at 12.92 ka BP and lasted for 430 years. The occurrence of the 200-yr Older Dryas during the BA period was dated from 13.87 to 14.06 ka BP. The durations of the three Heinrich (H) events, H1, H2, and H3, are 14.33–18.29, 23.77–24.48, and 28.98–30.46 ka BP, respectively. Furong record shows surprisingly variable onset transitions of 980, 210, and 40 years for the corresponding weak ASM events. These discrepancies suggest different influences of the H events on ASM dynamics. During the periods of H 1–3, the obvious difference between our Furong record and NGRIP δ 18 O record indicated the decoupling correlation between the mid-low latitudes and high latitudes. On the other hand, synchronous climate change in high and low latitudes suggests another possibility which different to the dominant role of Northern high latitudes in triggering global climate change. Our high quality records also indicate a plausible different correlation between the high and mid-low latitudes under glacial and inter-glacial background, especially for the ASM regimes.
Formación de espeleotemas en el noreste peninsular y su relación con las condiciones climáticas durante los últimos ciclos glaciares
Publisher: Universidad de la Rioja
Date: 08-07-2013
DOI: 10.18172/CIG.1998
Abstract: Speleothem growing is closely linked to warm climates with a positive hydrological balance. Mild temperatures and hydrological availability are conditions that tend to stimulate soil CO2 production due to denser vegetation cover and higher microbial activity. In such situations, waters enriched with dissolved carbonate are common and can infiltrate in the karstic system. This study compiles 158 dates from 34 speleothems collected in nine caves in the Northeastern Iberia to distinguish the time intervals with speleothem formation. A clear connection of speleothem growth and interglacial periods is established but precesssional influence is also observed, being periods of maxima insolation those with ideal conditions to produce karstic formations such as speleothems. The Holocene is without doubt the best represented period in the available records. However, last centuries were not characterized by an important development of speleothems in the studied caves.
Evidence of Holocene uplift in east New Britain, Papua New Guinea
Publisher: American Geophysical Union (AGU)
Date: 09-2006
DOI: 10.1029/2006GL026596
Formal Subdivision of the Holocene Series/Epoch: A Summary
Publisher: Springer Science and Business Media LLC
Date: 02-2019
Different response of stalagmite δ18O and δ13C to millennial-scale events during the last glacial, evidenced from Huangjin Cave, northern China
Publisher: Elsevier BV
Date: 2022
An annually laminated stalagmite record of the changes in Thailand monsoon rainfall over the past 387 years and its relationship to IOD and ENSO
Publisher: Elsevier BV
Date: 10-2014
Precise timing of MIS 7 substages from the Austrian Alps
Publisher: Copernicus GmbH
Date: 09-07-2021
Abstract: Abstract. Investigating the precise timing of regional-scale climate changes during glacial terminations and the interglacial periods that follow is key to unraveling the mechanisms behind these global climate shifts. Here, we present a high-precision time series of climate changes in the Austrian Alps that coincide with the later portion of Termination III (TIII), the entire penultimate interglacial (Marine Isotope Stage (MIS) 7), Termination IIIa (TIIIa), and the penultimate glacial inception (MIS 7–6 transition). Using state-of-the-art mass spectrometry techniques, we have constructed a uranium-series chronology with relative age uncertainties averaging 1.7 ‰ (2σ) for our study period (247 to 191 thousand years before present, ka). Results reveal the onset of warming in the Austrian Alps associated with TIII at 242.5 ± 0.2 ka and the duration of MIS 7e warming between 241.8 and 236.7 (±0.6) ka. An abrupt shift towards higher δ18O values at 216.8 ka marks the onset of regional warming associated with TIIIa. Two periods of high δ18O values (greater than −10 ‰ Vienna Pee Dee Belemnite (VPDB)) between 215.9–213.3 and 204.3–197.5 (±0.4) ka coincide with interglacial substages MIS 7c and 7a, respectively. Multiple fluorescent inclusions suggest a partial retreat of the local Alpine glacier during peak obliquity forcings at 214.3 ± 0.4 ka. Two newly collected stalagmites from Spannagel Cave (SPA146 and 183) provide high-resolution replications of the latter portion of the MIS 7a-to-6e transition. The resulting multi-stalagmite record reveals important chronological constraints on climate shifts in the Austrian Alps associated with MIS 7 while offering new insight into the timing of millennial-scale changes in the North Atlantic realm leading up to TIII and TIIIa.
Mass spectrometric U-series dating of New Cave at Zhoukoudian, China
Publisher: Elsevier BV
Date: 03-2004
Holocene ENSO-related cyclic storms recorded by magnetic minerals in speleothems of central China
Publisher: Proceedings of the National Academy of Sciences
Date: 17-01-2017
Abstract: High-resolution reconstructions of storm history and storms’ underlying mechanisms in inland areas are critical but limited by a paucity of suitable paleoproxies. Here we use soil-derived magnetic minerals preserved in a stalagmite as a new paleohydrological proxy. This proxy enables us to rebuild decadal resolution storm records in the eastern Asian monsoon area since 8.6 ky. Variance of storms in central China was found to exhibit close correlation with El Niño−Southern Oscillation activity at millennial and centennial time scales, and also occur on a significant 500-y cycle related to periodic solar activity. These findings shed light on the forecasting of future floods and improve our understanding of the potential mechanism of strong precipitation in monsoon regions.
Erratum to C.-C. Shen, K.-S. Li, K. Sieh, D. Natawidjaja, H. Cheng, X. Wang, R. L. Edwards, D. D. Lam, Y.-T. Hsieh, T.-Y. Fan, A. J. Meltzner, F. W. Taylor, T. M. Quinn, H.-W. Chiang, and K. H. Kilbou
Publisher: Elsevier BV
Date: 12-2008
Permafrost thaw induced abrupt changes in hydrology and carbon cycling in Lake Wudalianchi, northeastern China
Publisher: Geological Society of America
Date: 03-06-2021
DOI: 10.1130/G48891.1
Abstract: Lakes in the permafrost zone have been proposed to serve as key outlets for methane and carbon dioxide emissions. However, there has been no geological record of the hydrological and biogeochemical responses of lakes throughout the thawing of surrounding permafrost. We use multiple biomarker and isotopic proxies to reconstruct hydrological and biogeo-chemical changes in Lake Wudalianchi in northeastern China during regional thawing of the permafrost. We show permafrost thawing, as indicated by lignin degradation, initiated rapid lake water freshening as a result of the opening of groundwater conduits, and negative organic δ13C excursion due to increased inorganic and organic carbon fluxes. These hydro-logical changes were followed, with an ∼5–7 yr delay, by abrupt and persistent increases in microbial lake methanotrophy and methanogenesis, indicating enhanced anaerobic organic decomposition and methane emissions from lakes as permafrost thaws. Our data provide a detailed assessment of the processes involved during permafrost thaw, and highlight the importance of lakes in ventilating greenhouse gases to the atmosphere.
High resolution Secondary Ionisation Mass Spectrometry (SIMS) δ18O analyses of Hulu Cave speleothem at the time of Heinrich Event 1
Publisher: Elsevier BV
Date: 03-2007
Speleothem‐based chronology and environmental context of deposits from the Mishin Kamik Cave, NW Bulgaria – A contribution to the archaeological study of the Late Pleistocene human occupation in the B
Publisher: Wiley
Date: 25-08-2021
DOI: 10.1002/JQS.3364
Abstract: The Balkan Peninsula represents one of the most important human pathways into and out of Europe during the Pleistocene. Mishin Kamik cave, located in the karst region of Western Stara Planina, has a rich faunal content and shows promising features indicating a human occupation site with the discovery of potential bone artefacts and an intriguing accumulation of bear skulls and bones. Petrographic study and U‐series dating of a stalagmite and other calcite deposits in the cave provide an absolute chronological frame for the detrital infillings and their archaeological content and inform the environmental and climatic context of the cave evolution. Most detrital deposits in the cave were probably deposited before Marine Isotope Stage (MIS) 5 and the cave morphology and sedimentary deposits display current morphologies since ~135 ka. Consequently, the palaeontological and archaeological findings are older than ~135 ka. Calcite dated on and under the accumulation of bear skulls and bones suggests deposition during MIS 7. A first depositional contextualization of the bone accumulation does not allow us to discriminate between a natural or anthropogenic origin. The study emphasizes the added value of speleothem studies in archaeological sites and particularly in bringing a well‐constrained chronological and environmental framework.
Rapid sea-level fall and deep-ocean temperature change since the last interglacial period
Publisher: Elsevier BV
Date: 02-2003
Evidence of thermophilisation and elevation-dependent warming during the Last Interglacial in the Italian Alps
Publisher: Springer Science and Business Media LLC
Date: 08-02-2018
DOI: 10.1038/S41598-018-21027-3
Abstract: Thermophilisation is the response of plants communities in mountainous areas to increasing temperatures, causing an upward migration of warm-adapted (thermophilic) species and consequently, the timberline. This greening, associated with warming, causes enhanced evapotranspiration that leads to intensification of the hydrological cycle, which is recorded by hydroclimate-sensitive archives, such as stalagmites and flowstones formed in caves. Understanding how hydroclimate manifests at high altitudes is important for predicting future water resources of many regions of Europe that rely on glaciers and snow accumulation. Using proxy data from three coeval speleothems (stalagmites and flowstone) from the Italian Alps, we reconstructed both the ecosystem and hydrological setting during the Last Interglacial (LIG) a warm period that may provide an analogue to a near-future climate scenario. Our speleothem proxy data, including calcite fabrics and the stable isotopes of calcite and fluid inclusions, indicate a +4.3 ± 1.6 °C temperature anomaly at ~2000 m a.s.l. for the peak LIG, with respect to present-day values (1961–1990). This anomaly is significantly higher than any low-altitude reconstructions for the LIG in Europe, implying elevation-dependent warming during the LIG. The enhanced warming at high altitudes must be accounted for when considering future climate adaption strategies in sensitive mountainous regions.
A 900‐year (600 to 1500 A.D.) record of the Indian summer monsoon precipitation from the core monsoon zone of India
Publisher: American Geophysical Union (AGU)
Date: 21-08-2007
DOI: 10.1029/2007GL030431
Timescales of hydrothermal scavenging in the South Pacific Ocean from 234Th, 230Th, and 228Th
Publisher: Elsevier BV
Date: 2019
Hydroclimate footprint of pan-Asian monsoon water isotope during the last deglaciation
Publisher: American Association for the Advancement of Science (AAAS)
Date: 22-01-2021
Abstract: Pan-Asian monsoon water isotope variability is found accompanied by a continental-scale hydroclimate footprint.
Precipitation changes over the eastern Bolivian Andes inferred from speleothem (δ18O) records for the last 1400 years
Publisher: Elsevier BV
Date: 07-2018
A quick cooling event of the East Asian monsoon responding to Heinrich Event 1: Evidence from stalagmite δ18O records
Publisher: Springer Science and Business Media LLC
Date: 12-2002
DOI: 10.1007/BF02879700
Anatomy of a late Quaternary carbonate island: Constraints on timing and magnitude of sea-level fluctuations, West Caicos, Turks and Caicos Islands, BWI
Publisher: Elsevier BV
Date: 02-2019
Correction to “A dry episode during the Younger Dryas and centennial‐scale weak monsoon events during the early Holocene: A high‐resolution stalagmite record from southeast of the Loess Plateau, China
Publisher: American Geophysical Union (AGU)
Date: 02-2008
DOI: 10.1029/2008GL033399
A critical humidity threshold for monsoon transitions
Publisher: Copernicus GmbH
Date: 15-03-2012
Abstract: Abstract. Monsoon systems around the world are governed by the so-called moisture-advection feedback. Here we show that, in a minimal conceptual model, this feedback implies a critical threshold with respect to the atmospheric specific humidity qo over the ocean adjacent to the monsoon region. If qo falls short of this critical value qoc, monsoon rainfall over land cannot be sustained. Such a case could occur if evaporation from the ocean was reduced, e.g. due to low sea surface temperatures. Within the restrictions of the conceptual model, we estimate qoc from present-day reanalysis data for four major monsoon systems, and demonstrate how this concept can help understand abrupt variations in monsoon strength on orbital timescales as found in proxy records.
Timing and structure of the weak Asian Monsoon event about 73,000 years ago
Publisher: Elsevier BV
Date: 08-2019
Abrupt changes in Indian summer monsoon strength during 33,800 to 5500 years B.P.
Publisher: American Geophysical Union (AGU)
Date: 07-07-2015
DOI: 10.1002/2015GL064015
Radiocarbon Calibration/Comparison Records Based on Marine Sediments from the Pakistan and Iberian Margins
Publisher: Cambridge University Press (CUP)
Date: 2013
DOI: 10.2458/AZU_JS_RC.55.17114
Abstract: We present a new record of radiocarbon ages measured by accelerator mass spectrometry (AMS) on a deep-sea core collected off the Pakistan Margin. The 14 C ages measured on the planktonic foraminifera Globigerinoides ruber from core MD04-2876 define a high and stable sedimentation rate on the order of 50 cm/kyr over the last 50 kyr. The site is distant from the main upwelling zone of the western Arabian Sea where 14 C reservoir age is large and may be variable. Many independent proxies based on elemental analyses, mineralogy, biomarkers, isotopic proxies, and foraminiferal abundances show abrupt changes correlative with Dansgaard-Oeschger and Heinrich events. It is now common knowledge that these climatic events also affected the Arabian Sea during the last glacial period through changes in the Indian monsoon and in ventilation at intermediate depths. The stratigraphic agreement between all proxies, from fine- to coarse-size fractions, indicates that the foraminiferal 14 C ages are representative of the different sediment fractions. To build a calendar age scale for core MD04-2876, we matched its climate record to the oxygen isotopic (δ 18 O) profile of Hulu Cave stalagmites that have been accurately dated by U-Th (Wang et al. 2001 Southon et al. 2012 Edwards et al., submitted). Both archives exhibit very similar signatures, even for century-long events linked to monsoonal variations. For comparison, we have also updated our previous work on core MD95-2042 from the Iberian Margin (Bard et al. 2004a,b,c), whose climate record has likewise been tuned to the high-resolution δ 18 O Hulu Cave profile. Sophisticated and novel statistical techniques were used to interpolate ages and calculate uncertainties between chronological tie-points (Heaton et al. 2013, this issue). The data from the Pakistan and Iberian margins compare well even if they come from distant sites characterized by different oceanic conditions. Collectively, the data also compare well with the IntCal09 curve, except for specific intervals around 16 cal kyr BP and from 28 to 31 cal kyr BP. During these intervals, the data indicate that 14 C is somewhat older than indicated by the IntCal09 curve. Agreement between the data from both oceanic sites suggests that the discrepancy is not due to local changes of sea-surface 14 C reservoir ages, but rather that the IntCal09 curve needed to be updated in these intervals as has been done in the framework of IntCal13 (Reimer et al. 2013a, this issue).
U-series dating and taphonomy of Quaternary vertebrates from Brazilian caves
Publisher: Elsevier BV
Date: 10-2006
Decreasing monsoon precipitation in southwest China during the last 240 years associated with the warming of tropical ocean
Publisher: Springer Science and Business Media LLC
Date: 21-05-2016
ENSO Drove 2500-Year Collapse of Eastern Pacific Coral Reefs
Publisher: American Association for the Advancement of Science (AAAS)
Date: 06-07-2012
Abstract: Coral reefs are threatened by global warming and ocean acidification, and so it is important to understand better how and why environmental changes have affected them in the past. Toth et al. (p. 81 ) present a 6000-year-long record of coral reefs off the coast of Panama, Central America. The reefs effectively stopped growing for approximately 2600 years, beginning around 4000 years ago. This collapse of the coral reef system was probably caused by increased variability of ENSO, the El Nino–Southern Oscillation. If the strength or frequency of ENSO were to increase, the viability of these and other reef systems in the Pacific could be put further at risk.
The global monsoon across timescales: coherent variability of regional monsoons
Publisher: Copernicus GmbH
Date: 21-11-2014
Abstract: Abstract. Monsoon has earned increasing attention from the climate community since the last century, yet only recently have regional monsoons been recognized as a global system. It remains a debated issue, however, as to what extent and at which timescales the global monsoon can be viewed as a major mode of climate variability. For this purpose, a PAGES (Past Global Changes) working group (WG) was set up to investigate the concept of the global monsoon and its future research directions. The WG's synthesis is presented here. On the basis of observation and proxy data, the WG found that the regional monsoons can vary coherently, although not perfectly, at various timescales, varying between interannual, interdecadal, centennial, millennial, orbital and tectonic timescales, conforming to the global monsoon concept across timescales. Within the global monsoon system, each subsystem has its own features, depending on its geographic and topographic conditions. Discrimination between global and regional components in the monsoon system is a key to revealing the driving factors in monsoon variations hence, the global monsoon concept helps to enhance our understanding and to improve future projections of the regional monsoons. This paper starts with a historical review of the global monsoon concept in both modern and paleo-climatology, and an assessment of monsoon proxies used in regional and global scales. The main body of the paper is devoted to a summary of observation data at various timescales, providing evidence of the coherent global monsoon system. The paper concludes with a projection of future monsoon shifts in a warming world. The synthesis will be followed by a companion paper addressing driving mechanisms and outstanding issues in global monsoon studies.
Gas Hydrate Dissociation During Sea‐Level Highstand Inferred From U/Th Dating of Seep Carbonate From the South China Sea
Publisher: American Geophysical Union (AGU)
Date: 06-12-2019
DOI: 10.1029/2019GL085643
Protactinium-231 Dating of Carbonates by Thermal Ionization Mass Spectrometry: Implications for Quaternary Climate Change
Publisher: American Association for the Advancement of Science (AAAS)
Date: 02-05-1997
DOI: 10.1126/SCIENCE.276.5313.782
Abstract: Measurement of protactinium-231 ( 231 Pa) in carbonates by thermal ionization mass spectroscopy yields 231 Pa ages that are more than 10 times more precise than those determined by decay counting. Carbonates between 10 and 250,000 years old can now be dated with 231 Pa methods. Barbados corals that have identical 231 Pa and thorium-230 ( 230 Th) ages indicate that the timing of sea level change over parts of the last glacial cycle is consistent with the predictions of the Astronomical Theory. Two Devils Hole calcite subs les record identical 231 Pa and 230 Th ages, suggesting that the chronology of this climate record is accurate.
Paleoclimate reconstruction in the Levant region from the geochemistry of a Holocene stalagmite from the Jeita cave, Lebanon
Publisher: Cambridge University Press (CUP)
Date: 11-2008
DOI: 10.1016/J.YQRES.2008.05.004
Abstract: Dated oxygen and carbon isotopic profiles from a Holocene stalagmite (11.9–1.1 ka) from the Jeita cave, Lebanon, are compared to variations in crystallographic habit, stalagmite diameter and growth rate. The profiles show generally high δ 18 O and δ 13 C values during the late-glacial period, low values during the early Holocene, and again high values after 5.8 ka. On the basis of the good correlation between the morphological and crystallographic aspect of the stalagmite and its isotopic records, as well as the isotopic response of speleothems from central and northern Israel, we relate high δ 18 O and δ 13 C values to drier conditions. Between 6.5 and 5.8 ka an increase in isotopic values, a decrease in growth rate and stalagmite diameter suggest a transition from wet conditions in the early Holocene towards drier conditions in the mid-Holocene. The transition occurred in two steps, first a progressive change to drier conditions started at 6.5 ka but was interrupted by a short (∼ 100 years) return to wetter conditions, followed by an equally rapid ( 200 years) change to drier conditions.
Megadrought and cultural exchange along the proto-silk road
Publisher: Elsevier BV
Date: 03-2021
Earthquake Supercycles Inferred from Sea-Level Changes Recorded in the Corals of West Sumatra
Publisher: American Association for the Advancement of Science (AAAS)
Date: 12-12-2008
Abstract: Records of relative sea-level change extracted from corals of the Mentawai islands, Sumatra, imply that this 700-kilometer-long section of the Sunda megathrust has generated broadly similar sequences of great earthquakes about every two centuries for at least the past 700 years. The moment magnitude 8.4 earthquake of September 2007 represents the first in a series of large partial failures of the Mentawai section that will probably be completed within the next several decades.
Freshwater tufa record from Spain supports evidence for the past interglacial being wetter than the Holocene in the Mediterranean region
Publisher: Elsevier BV
Date: 06-2011
Last interglacial hydroclimate in the Italian Prealps reconstructed from speleothem multi-proxy records (Bigonda Cave, NE Italy)
Publisher: Elsevier BV
Date: 11-2021
Melting of the Earth's lithospheric mantle inferred from protactinium– thorium–uranium isotopic data
Publisher: Springer Science and Business Media LLC
Date: 07-2000
DOI: 10.1038/35018550
Abstract: The processes responsible for the generation of partial melt in the Earth's lithospheric mantle and the movement of this melt to the Earth's surface remain enigmatic, owing to the perceived difficulties in generating large-degree partial melts at depth and in transporting small-degree melts through a static lithosphere. Here we present a method of placing constraints on melting in the lithospheric mantle using 231Pa-235U data obtained from continental basalts in the southwestern United States and Mexico. Combined with 230Th-238U data, the 231Pa-235U data allow us to constrain the source mineralogy and thus the depth of melting of these basalts. Our analysis indicates that it is possible to transport small melt fractions--of the order of 0.1%--through the lithosphere, as might result from the coalescence of melt by compaction owing to melting-induced deformation. The large observed 231Pa excesses require that the timescale of melt generation and transport within the lithosphere is small compared to the half-life of 231Pa (approximately 32.7 kyr). The 231Pa-230Th data also constrain the thorium and uranium distribution coefficients for clinopyroxene in the source regions of these basalts to be within 2% of one another, indicating that in this setting 230Th excesses are not expected during melting at depths shallower than 85 km.
Contribution of ENSO variability to the East Asian summer monsoon in the late Holocene
Publisher: Elsevier BV
Date: 05-2016
Abrupt Freshening Since the Early Little Ice Age in Lake Sayram of Arid Central Asia Inferred From an Alkenone Isomer Proxy
Publisher: American Geophysical Union (AGU)
Date: 14-08-2020
DOI: 10.1029/2020GL089257
Abstract: Hydroclimatic variations of arid central Asia (ACA) significantly impact regional ecosystems and human civilizations. Here we present a lake water salinity record of the last 3,000 years from Lake Sayram in the core area of ACA using a new alkenone isomer‐based RIK 37 index. Our record shows an abrupt decrease in salinity by more than 5‰ since the “early” Little Ice Age (LIA) (about CE 1150), which can be attributed to the combined effect of regional wetting, cooling, and topographic features. Combined with other moisture records in the region, we find two periods of relatively wet conditions during CE 1150–1550 and 1850 to present, which may be linked to Arctic sea ice expansion due to natural variability and, from CE 1950, anthropogenically induced warming. The wet conditions during CE 1206–1260 may have favored the spread of the Mongol Empire across the entire core area of ACA.
Timing of Neanderthal occupations in the southeastern margins of the Massif Central (France): A multi-method approach
Publisher: Elsevier BV
Date: 12-2021
High‐resolution reconstruction of 8.2‐ka BP event documented in Père Noël cave, southern Belgium
Publisher: Wiley
Date: 10-09-2018
DOI: 10.1002/JQS.3064
Global climate evolution during the last deglaciation
Publisher: Proceedings of the National Academy of Sciences
Date: 13-02-2012
Abstract: Deciphering the evolution of global climate from the end of the Last Glacial Maximum approximately 19 ka to the early Holocene 11 ka presents an outstanding opportunity for understanding the transient response of Earth’s climate system to external and internal forcings. During this interval of global warming, the decay of ice sheets caused global mean sea level to rise by approximately 80 m terrestrial and marine ecosystems experienced large disturbances and range shifts perturbations to the carbon cycle resulted in a net release of the greenhouse gases CO 2 and CH 4 to the atmosphere and changes in atmosphere and ocean circulation affected the global distribution and fluxes of water and heat. Here we summarize a major effort by the paleoclimate research community to characterize these changes through the development of well-dated, high-resolution records of the deep and intermediate ocean as well as surface climate. Our synthesis indicates that the superposition of two modes explains much of the variability in regional and global climate during the last deglaciation, with a strong association between the first mode and variations in greenhouse gases, and between the second mode and variations in the Atlantic meridional overturning circulation.
Hydroclimate changes across the Amazon lowlands over the past 45,000 years
Publisher: Springer Science and Business Media LLC
Date: 2017
DOI: 10.1038/NATURE20787
Abstract: Reconstructing the history of tropical hydroclimates has been difficult, particularly for the Amazon basin-one of Earth's major centres of deep atmospheric convection. For ex le, whether the Amazon basin was substantially drier or remained wet during glacial times has been controversial, largely because most study sites have been located on the periphery of the basin, and because interpretations can be complicated by sediment preservation, uncertainties in chronology, and topographical setting. Here we show that rainfall in the basin responds closely to changes in glacial boundary conditions in terms of temperature and atmospheric concentrations of carbon dioxide. Our results are based on a decadally resolved, uranium/thorium-dated, oxygen isotopic record for much of the past 45,000 years, obtained using speleothems from Paraíso Cave in eastern Amazonia we interpret the record as being broadly related to precipitation. Relative to modern levels, precipitation in the region was about 58% during the Last Glacial Maximum (around 21,000 years ago) and 142% during the mid-Holocene epoch (about 6,000 years ago). We find that, as compared with cave records from the western edge of the lowlands, the Amazon was widely drier during the last glacial period, with much less recycling of water and probably reduced plant transpiration, although the rainforest persisted throughout this time.
Corrigendum to “Changing amounts and sources of moisture in the U.S. southwest since the Last Glacial Maximum in response to global climate change” [Earth Planet. Sci. Lett. 401 (2014) 47–56]
Publisher: Elsevier BV
Date: 12-2014
Atmospheric
Publisher: American Association for the Advancement of Science (AAAS)
Date: 14-12-2018
Abstract: Paired measurements of
The Asian monsoon over the past 640,000 years and ice age terminations
Publisher: Springer Science and Business Media LLC
Date: 29-06-2016
DOI: 10.1038/NATURE18591
Abstract: Oxygen isotope records from Chinese caves characterize changes in both the Asian monsoon and global climate. Here, using our new speleothem data, we extend the Chinese record to cover the full uranium/thorium dating range, that is, the past 640,000 years. The record's length and temporal precision allow us to test the idea that insolation changes caused by the Earth's precession drove the terminations of each of the last seven ice ages as well as the millennia-long intervals of reduced monsoon rainfall associated with each of the terminations. On the basis of our record's timing, the terminations are separated by four or five precession cycles, supporting the idea that the '100,000-year' ice age cycle is an average of discrete numbers of precession cycles. Furthermore, the suborbital component of monsoon rainfall variability exhibits power in both the precession and obliquity bands, and is nearly in anti-phase with summer boreal insolation. These observations indicate that insolation, in part, sets the pace of the occurrence of millennial-scale events, including those associated with terminations and 'unfinished terminations'.
Preparation of high-precision CO2 with known triple oxygen isotope for oxygen isotope analysis
Publisher: Informa UK Limited
Date: 12-08-2021
A petrographic and geochemical record of climate change over the last 4600years from a northern Namibia stalagmite, with evidence of abruptly wetter climate at the beginning of southern Africa's Iron
Publisher: Elsevier BV
Date: 04-2013
Three distinct Holocene intervals of stalagmite deposition and nondeposition revealed in NW Madagascar, and their paleoclimate implications
Publisher: Copernicus GmbH
Date: 04-12-2017
Abstract: Abstract. Petrographic features, mineralogy, and stable isotopes from two stalagmites, ANJB-2 and MAJ-5, respectively from Anjohibe and Anjokipoty caves, allow distinction of three intervals of the Holocene in NW Madagascar. The Malagasy early Holocene (between ca. 9.8 and 7.8 ka) and late Holocene (after ca. 1.6 ka) intervals (MEHI and MLHI, respectively) record evidence of stalagmite deposition. The Malagasy middle Holocene interval (MMHI, between ca. 7.8 and 1.6 ka) is marked by a depositional hiatus of ca. 6500 years. Deposition of these stalagmites indicates that the two caves were sufficiently supplied with water to allow stalagmite formation. This suggests that the MEHI and MLHI intervals may have been comparatively wet in NW Madagascar. In contrast, the long-term depositional hiatus during the MMHI implies it was relatively drier than the MEHI and the MLHI. The alternating wet–dry–wet conditions during the Holocene may have been linked to the long-term migrations of the Intertropical Convergence Zone (ITCZ). When the ITCZ's mean position is farther south, NW Madagascar experiences wetter conditions, such as during the MEHI and MLHI, and when it moves north, NW Madagascar climate becomes drier, such as during the MMHI. A similar wet–dry–wet succession during the Holocene has been reported in neighboring locations, such as southeastern Africa. Beyond these three sub isions, the records also suggest wet conditions around the cold 8.2 ka event, suggesting a causal relationship. However, additional Southern Hemisphere high-resolution data will be needed to confirm this.
Holocene climate change in southern Oman deciphered by speleothem records and climate model simulations
Publisher: Springer Science and Business Media LLC
Date: 05-08-2023
DOI: 10.1038/S41467-023-40454-Z
Abstract: Qunf Cave oxygen isotope (δ 18 O c ) record from southern Oman is one of the most significant of few Holocene Indian summer monsoon cave records. However, the interpretation of the Qunf δ 18 O c remains in dispute. Here we provide a multi-proxy record from Qunf Cave and climate model simulations to reconstruct the Holocene local and regional hydroclimate changes. The results indicate that besides the Indian summer monsoon, the North African summer monsoon also contributes water vapor to southern Oman during the early to middle Holocene. In principle, Qunf δ 18 O c values reflect integrated oxygen-isotope fractionations over a broad moisture transport swath from moisture sources to the cave site, rather than local precipitation amount alone, and thus the Qunf δ 18 O c record characterizes primary changes in the Afro-Asian monsoon regime across the Holocene. In contrast, local climate proxies appear to suggest an overall slightly increased or unchanged wetness over the Holocene at the cave site.
Abrupt climate change of East Asian Monsoon at 130 kaBP inferred from a high resolu-tion stalagmite δ18O record
Publisher: Science China Press., Co. Ltd.
Date: 2005
DOI: 10.1360/982004-819
Moisture availability in the southwest United States over the last three glacial-interglacial cycles
Publisher: American Association for the Advancement of Science (AAAS)
Date: 05-10-2018
Abstract: Caves in Death Valley National Park reveal past water table fluctuations in response to 350,000 years of global climate change.
Penultimate deglaciation Asian monsoon response to North Atlantic circulation collapse
Publisher: Springer Science and Business Media LLC
Date: 18-11-2021
DOI: 10.1038/S41561-021-00851-9
Abstract: During glacial terminations, massive iceberg discharges and meltwater pulses in the North Atlantic triggered a shutdown of the Atlantic Meridional Overturning Circulation (AMOC). Speleothem calcium carbonate oxygen isotope records (δ 18 O Cc ) indicate that the collapse of the AMOC caused dramatic changes in the distribution and variability of the East Asian and Indian monsoon rainfall. However, the mechanisms linking changes in the intensity of the AMOC and Asian monsoon δ 18 O Cc are not fully understood. Part of the challenge arises from the fact that speleothem δ 18 O Cc depends on not only the δ 18 O of precipitation but also temperature and kinetic isotope effects. Here we quantitatively deconvolve these parameters affecting δ 18 O Cc by applying three geochemical techniques in speleothems covering the penultimate glacial termination. Our data suggest that the weakening of the AMOC during meltwater pulse 2A caused substantial cooling in East Asia and a shortening of the summer monsoon season, whereas the collapse of the AMOC during meltwater pulse 2B (133,000 years ago) also caused a dramatic decrease in the intensity of the Indian summer monsoon. These results reveal that the different modes of the AMOC produced distinct impacts on the monsoon system.
Human activity and climate change triggered the expansion of rocky desertification in the karst areas of Southwestern China
Publisher: Springer Science and Business Media LLC
Date: 09-08-2021
U-Th and radiocarbon dating of calcite speleothems from gypsum caves (Emilia Romagna, North Italy)
Publisher: Elsevier BV
Date: 06-2019
COnstructing Proxy Records from Age models (COPRA)
Publisher: Copernicus GmbH
Date: 31-10-2012
Abstract: Abstract. Reliable age models are fundamental for any palaeoclimate reconstruction. Available interpolation procedures between age control points are often inadequately reported, and very few translate age uncertainties to proxy uncertainties. Most available modeling algorithms do not allow incorporation of layer counted intervals to improve the confidence limits of the age model in question. We present a framework that allows detection and interactive handling of age reversals and hiatuses, depth-age modeling, and proxy-record reconstruction. Monte Carlo simulation and a translation procedure are used to assign a precise time scale to climate proxies and to translate dating uncertainties to uncertainties in the proxy values. The presented framework allows integration of incremental relative dating information to improve the final age model. The free software package COPRA1.0 facilitates easy interactive usage.
Early Last Interglacial environmental changes recorded by speleothems from Katerloch (south‐east Austria)
Publisher: Wiley
Date: 14-12-2021
DOI: 10.1002/JQS.3398
Abstract: In the European Alps, the Last Interglacial (LIG, ~129–116 ka) has been primarily studied using pollen preserved in mires and lake sediments. These records document the vegetation succession across the LIG, but are poorly constrained chronologically. Here, we present a precisely dated stable isotope record for the early LIG (129.6 ± 0.4 to 125.0 ± 0.8 ka) based on two stalagmites from Katerloch, a cave located on the south‐eastern side of the Alps. The onset of the interglacial is marked by a sharp rise in the oxygen isotope values at 129.4 ± 0.4 ka, consistent within dating uncertainty with the timing of Termination II as recorded by other Alpine speleothems. Carbon isotope values show an equally prominent drop at Termination II and the establishment of a forest ecosystem. Although concentrations are low, pollen from these stalagmites provide insights into how the local vegetation changed across the first five millennia of the LIG. The spectra indicate a vegetation optimum recorded by the occurrence of warm‐demanding taxa typical of the Eemian mesocratic phase. By combining stable isotopes and pollen data, we propose an absolutely dated chronological framework for peri‐Alpine pollen successions from lacustrine sediments covering the first half of the LIG.
Reconciliation of the Devils Hole climate record with orbital forcing
Publisher: American Association for the Advancement of Science (AAAS)
Date: 08-01-2016
Abstract: Glacial cycles are in part controlled by the pattern of incident solar energy determined by the geometry of Earth's orbit around the Sun. The classic record of the penultimate deglaciation from Devils Hole, Nevada, did not reconcile the presumption of so-called orbital forcing, however, suggesting that deglaciation began ~10,000 years too early. Moseley et al. present analyses of a new set of data from Devils Hole that show that the deglaciation indeed occurred at the time expected on the basis of orbital forcing. The age offset displayed by the older s les apparently was caused by interaction with groundwater, which preferentially affected the deeper original s les but not the new shallower s les. Science , this issue p. 165
The timing and structure of the 8.2 ka event revealed through high-resolution speleothem records from northwestern Madagascar
Publisher: Elsevier BV
Date: 09-2021
Comment on “On linking climate to Chinese dynastic change: Spatial and temporal variations of monsoonal rain”
Publisher: Springer Science and Business Media LLC
Date: 11-2010
North Atlantic storm track changes during the Last Glacial Maximum recorded by Alpine speleothems
Publisher: Springer Science and Business Media LLC
Date: 27-02-2015
DOI: 10.1038/NCOMMS7344
Abstract: The European Alps are an effective barrier for meridional moisture transport and are thus uniquely placed to record shifts in the North Atlantic storm track pattern associated with the waxing and waning of Late-Pleistocene Northern Hemisphere ice sheets. The lack of well-dated terrestrial proxy records spanning this time period, however, renders the reconstruction of past atmospheric patterns difficult. Here we present a precisely dated, continuous terrestrial record of meteoric precipitation in Europe between 30 and 14.7 ka. In contrast to present-day conditions, our speleothem data provide strong evidence for preferential advection of moisture from the South across the Alps supporting a southward shift of the storm track during the local Last Glacial Maximum (that is, 26.5–23.5 ka). Moreover, our age control indicates that this circulation pattern preceded the Northern Hemisphere precession maximum by ~3 ka, suggesting that obliquity may have played a considerable role in the Alpine ice aggradation.
Variability of Southwest Indian summer monsoon precipitation during the Bølling-Ållerød
Publisher: Geological Society of America
Date: 2005
DOI: 10.1130/G21498.1
Response to Comments on “Reconciliation of the Devils Hole climate record with orbital forcing”
Publisher: American Association for the Advancement of Science (AAAS)
Date: 20-10-2016
Abstract: Winograd and Coplen question the thorium-230 distribution model proposed to explain the age bias observed with increasing depth during Termination II. We have evaluated both criticisms and find that all s les display virtually identical fabrics, argue that the modern setting is not analogous to the conditions during Termination II, and reiterate the robustness of our age models. Our conclusions remain unchanged.
Cyclic changes of Asian monsoon intensity during the early mid-Holocene from annually-laminated stalagmites, central China
Publisher: Elsevier BV
Date: 08-2015
Upper Pleistocene and Holocene palaeoenvironmental records in Cueva Mayor karst (Atapuerca, Spain) from different proxies: speleothem crystal fabrics, palynology, and archaeology
Publisher: University of South Florida Libraries
Date: 2014
Abrupt Indian summer monsoon shifts aligned with Heinrich events and D-O cycles since MIS 3
Publisher: Elsevier BV
Date: 12-2021
Response to Comments by Daniel Gebregiorgis et al. “A Brief Commentary on the Interpretation of Chinese Speleothem δ18O Records as Summer Monsoon Intensity Tracers”. Quaternary 2020, 3, 7
Publisher: MDPI AG
Date: 19-03-2020
DOI: 10.3390/QUAT3010008
Abstract: We would like to thank Gebregiorgis et al [...]
Contrasting Patterns in Abrupt Asian Summer Monsoon Changes in the Last Glacial Period and the Holocene
Publisher: American Geophysical Union (AGU)
Date: 02-2018
DOI: 10.1002/2017PA003294
Optically stimulated luminescence dating of young fluvial deposits of the Middle Elbe River Flood Plains using different age models
Publisher: Walter de Gruyter GmbH
Date: 20-12-2013
DOI: 10.2478/S13386-013-0140-7
Abstract: In the last few decades optically stimulated luminescence (OSL) dating has become an important tool in geochronological studies. The great advantage of the method, i.e. dating the depositional age of sediments directly, can be impaired by incomplete bleaching of grains. This can result in a scattered distribution of equivalent doses (DE), leading to incorrect estimation of the depositional age. Thoroughly tested protocols as well as good data analysis with adequate statistical methods are important to overcome this problem. In this study, s les from young fluvial sand and flood plain deposits from the Elbe River in northern Germany were investigated to compare its depositional ages from different age models with well-known historical dates. Coarse grain quartz (100–200 μm and 150–250 μm) and polymineral fine grains (4–11 μm) were dated using the single aliquot regenerative (SAR) dose protocol. The paleodose (DP) was calculated from the DE data set using different approaches. Results were compared with the development of the Elbe River, which is well-documented by historical records and maps covering the last 1,000 years. Depending on the statistical approach it can be demonstrated that depositional ages significantly differ from the most likely depositional age. For the investigated coarse grain quartz s les all ages calculated from the MAM-3UL, including their uncertainties, are within the historical documented age. Results of the polymineral fine grain s les are overestimating the historically documented depositional age, indicating undetectable incomplete bleaching. This study shows the importance of using an adequate statistical approach to calculate reliable OSL ages from fluvial sediments.
Marine isotope stage 8 millennial-scale variability as observed in the Asian monsoon
Publisher: Elsevier BV
Date: 08-2006
Age of the Laschamp excursion determined by U-Th dating of a speleothem geomagnetic record from North America
Publisher: Geological Society of America
Date: 04-01-2016
DOI: 10.1130/G37490.1
Archaic human remains from Hualongdong, China, and Middle Pleistocene human continuity and variation
Publisher: Proceedings of the National Academy of Sciences
Date: 29-04-2019
Abstract: Human evolution through the Middle to the Late Pleistocene in East Asia has been seen as reflecting erse groups and discontinuities vs. a continuity of form reflecting an evolving population. New Middle Pleistocene (∼300,000 y old) human remains from Hualongdong (HLD), China, provide further evidence for regional variation and the continuity of human biology through East Asian archaic humans. The HLD 6 skull is notable for its low and wide neurocranial vault and pronounced brow ridge, but less projecting face and modest chin. Along with the isolated teeth, the skull provides morphologically simple teeth with reduced or absent third molars. The remains foreshadow changes evident with modern human emergence, but primarily reinforce Old World continuity through Middle to Late Pleistocene humans.
Millennial and orbital scale variability of the South American Monsoon during the penultimate glacial period
Publisher: Springer Science and Business Media LLC
Date: 04-02-2019
DOI: 10.1038/S41598-018-37854-3
Abstract: The presence of large, rapid climate oscillations is the most prominent feature of the Earth’s last glacial period. These oscillations are observed throughout the Northern Hemisphere and into the Southern Hemisphere tropics. Whether similar oscillations are typical of prior glacial periods, however, has not been well established. Here, we present results of a study of the South American Summer Monsoon system that covers nearly the entire penultimate glacial period, from 195 to 135 ky BP. We use a well-dated, high-resolution (~50 y) time series of oxygen isotopes to show that the precession of the earth’s orbit is the primary control on monsoon intensity. After removing the precession signal we observe millennial oscillations that are very similar in litude and structure to the Dansgaard/Oeschger cycles of the last interglacial and that match well a synthetic reconstruction of millennial variability. Time series analyses shows that the most prominent of the observed cycles occur at considerably longer frequency (~3500 y) that the Dansgaard/Oeschger cycles from Marine Isotope Stages 2–4.
Changing amounts and sources of moisture in the U.S. southwest since the Last Glacial Maximum in response to global climate change
Publisher: Elsevier BV
Date: 09-2014
The Asian Summer Monsoon: Teleconnections and Forcing Mechanisms—A Review from Chinese Speleothem δ18O Records
Publisher: MDPI AG
Date: 07-0012
DOI: 10.3390/QUAT2030026
Abstract: Asian summer monsoon (ASM) variability significantly affects hydro-climate, and thus socio-economics, in the East Asian region, where nearly one-third of the global population resides. Over the last two decades, speleothem δ18O records from China have been utilized to reconstruct ASM variability and its underlying forcing mechanisms on orbital to seasonal timescales. Here, we use the Speleothem Isotopes Synthesis and Analysis database (SISAL_v1) to present an overview of hydro-climate variability related to the ASM during three periods: the late Pleistocene, the Holocene, and the last two millennia. We highlight the possible global teleconnections and forcing mechanisms of the ASM on different timescales. The longest composite stalagmite δ18O record over the past 640 kyr BP from the region demonstrates that ASM variability on orbital timescales is dominated by the 23 kyr precessional cycles, which are in phase with Northern Hemisphere summer insolation (NHSI). During the last glacial, millennial changes in the intensity of the ASM appear to be controlled by North Atlantic climate and oceanic feedbacks. During the Holocene, changes in ASM intensity were primarily controlled by NHSI. However, the spatio-temporal distribution of monsoon rain belts may vary with changes in ASM intensity on decadal to millennial timescales.
Ice Age Terminations
Publisher: American Association for the Advancement of Science (AAAS)
Date: 09-10-2009
Abstract: Rocky deposits in caves in central China record the changes over time in the Asian Monsoon through the oxygen isotopic composition of the minerals from which they are formed. These deposits can be precisely dated and provide an absolute time line for climate system changes. Cheng et al. (p. 248 see the Perspective by Severinghaus ) present oxygen isotope data from speleothems collected from Sanbao Cave, China, for the three glacial terminations that occurred between 120,000 and 350,000 years ago. The data reveal variations in the amount of precipitation delivered by the Asian Monsoon over time. Comparison of the timing of these changes with corresponding changes in ice core and marine sedimentary records provides mechanistic insights into how variations in insolation affect ice sheets and ice age terminations.
Past abrupt changes, tipping points and cascading impacts in the Earth system
Publisher: Springer Science and Business Media LLC
Date: 29-07-2021
Pleistocene water intrusions from the Mediterranean and Caspian seas into the Black Sea
Publisher: Springer Science and Business Media LLC
Date: 13-03-2011
DOI: 10.1038/NGEO1106
Orbital-scale Asian summer monsoon variations: Paradox and exploration
Publisher: Springer Science and Business Media LLC
Date: 24-02-2021
Effects of glaciation on karst hydrology and sedimentology during the Last Glacial Cycle: The case of Granito cave, Central Pyrenees (Spain)
Publisher: Elsevier BV
Date: 11-2021
Distributions of fatty acids in a stalagmite related to paleoclimate change at Qingjiang in Hubei, southern China
Publisher: Springer Science and Business Media LLC
Date: 09-2005
DOI: 10.1360/04YD0155
Lead concentrations and isotope ratios in speleothems as proxies for atmospheric metal pollution since the industrial revolution
Publisher: Elsevier BV
Date: 04-2015
Subdividing the Holocene Series/Epoch: formalization of stages/ages and subseries/subepochs, and designation of GSSPs and auxiliary stratotypes
Publisher: Wiley
Date: 04-2019
DOI: 10.1002/JQS.3097
Cryogenic cave carbonates in the Dolomites (northern Italy): insights into Younger Dryas cooling and seasonal precipitation
Publisher: Copernicus GmbH
Date: 06-04-2021
Abstract: Abstract. In the European Alps, the Younger Dryas (YD) was characterised by the last major glacier advance, with equilibrium line altitudes being ∼ 220 to 290 m lower than during the Little Ice Age, and also by the development of rock glaciers. Dating of these geomorphic features, however, is associated with substantial uncertainties, leading to considerable ambiguities regarding the internal structure of this stadial, which is the most intensively studied one of the last glacial period. Here, we provide robust physical evidence based on 230Th-dated cryogenic cave carbonates (CCCs) from a cave located at 2274 m a.s.l. in the Dolomites of northern Italy coupled with thermal modelling, indicating that early YD winters were only moderately cold in this part of the Alps. More precisely, we find that the mean annual air temperature dropped ≤ 3 ∘C at the Allerød–YD transition. Our data suggest that autumns and early winters in the early part of the YD were relatively snow-rich, resulting in stable winter snow cover. The latter insulated the shallow subsurface in winter and allowed the cave interior to remain close to the freezing point (0 ∘C) year-round, promoting CCC formation. The main phase of CCC precipitation at ∼ 12.2 ka coincided with the mid-YD transition recorded in other archives across Europe. Based on thermal modelling we propose that CCC formation at ∼ 12.2 ka was most likely associated with a slight warming of approximately +1 ∘C in conjunction with drier autumns and early winters in the second half of the YD. These changes triggered CCC formation in this Alpine cave as well as ice glacier retreat and rock glacier expansion across the Alps.
High resolution monsoon precipitation changes on southeastern Tibetan Plateau over the past 2300 years
Publisher: Elsevier BV
Date: 09-2018
Indian monsoon variability on millennial-orbital timescales
Publisher: No publisher found
Date: 2016
DOI: 10.1038/SREP24374
Formal ratification of the subdivision of the Holocene Series/Epoch (Quaternary System/Period): two new Global Boundary Stratotype Sections and Points (GSSPs) and three new stages/subseries
Publisher: International Union of Geological Sciences
Date: 12-2018
A dry episode during the Younger Dryas and centennial‐scale weak monsoon events during the early Holocene: A high‐resolution stalagmite record from southeast of the Loess Plateau, China
Publisher: American Geophysical Union (AGU)
Date: 2008
DOI: 10.1029/2007GL030986
Environmental influences on speleothem growth in southwestern Oregon during the last 380000 years
Publisher: Elsevier BV
Date: 30-03-2009
A multi-proxy climate record from a northwestern Botswana stalagmite suggesting wetness late in the Little Ice Age (1810–1820 CE) and drying thereafter in response to changing migration of the tropica
Publisher: Elsevier BV
Date: 10-2018
Wet periods in northeastern Brazil over the past 210 kyr linked to distant climate anomalies
Publisher: Springer Science and Business Media LLC
Date: 12-2004
DOI: 10.1038/NATURE03067
Abstract: The tropics are the main source of the atmosphere's sensible and latent heat, and water vapour, and are therefore important for reconstructions of past climate. But long, accurately dated records of southern tropical palaeoclimate, which would allow the establishment of climatic connections to distant regions, have not been available. Here we present a 210,000-year (210-kyr) record of wet periods in tropical northeastern Brazil--a region that is currently semi-arid. The record is obtained from speleothems and travertine deposits that are accurately dated using the U/Th method. We find wet periods that are synchronous with periods of weak East Asian summer monsoons, cold periods in Greenland, Heinrich events in the North Atlantic and periods of decreased river runoff to the Cariaco basin. We infer that the wet periods may be explained with a southward displacement of the Intertropical Convergence Zone. This widespread synchroneity of climate anomalies suggests a relatively rapid global reorganization of the ocean-atmosphere system. We conclude that the wet periods probably affected rainforest distribution, as plant fossils show that forest expansion occurred during these intermittent wet intervals, and opened a forest corridor between the Amazonian and Atlantic rainforests.
U/Th-dating living and young fossil corals from the central tropical Pacific
Publisher: Elsevier BV
Date: 05-2003
Correction to: Past Millennium Contrasting Hydroclimate Patterns Between Monsoonal Northern China and Arid Central Asia: a Modeling Study
Publisher: Springer Science and Business Media LLC
Date: 04-01-2019
Modeling of severe persistent droughts over eastern China during the last millennium
Publisher: Copernicus GmbH
Date: 28-05-2014
Abstract: Abstract. We use proxy data and modeled data from 1000 year model simulations with a variety of climate forcings to examine the occurrence of severe event of persistent drought over eastern China during the last millennium and diagnose the mechanisms. Results show that the model was able to roughly simulate most of these droughts over the study area during the last millennium such as those that occurred during the periods of 1123–1152, 1197–1223, 1353–1363, 1428–1449, 1479–1513, and 1632–1645. Our analyses suggest that these six well-captured droughts may caused by the East Asian summer monsoon (EASM) weakening. Study on the wavelet transform and spectral analysis reveals these events occurred all at the statistically significant 15–35-year timescale. A modeled data intercomparison suggests the possibility that solar activity may be the primary driver in the occurrence of the 1129–1144, 1354–1365, 1466–1491 and 1631–1648 droughts as identified by the model. However another possibility that these events may be related to internal variability cannot be excluded. Although the El Niño–Southern Oscillation (ENSO) plays an important role in monsoon variability, a temporally consistent relationship between the droughts and SST pattern in the Pacific Ocean could not be found either in the modeled or proxy data. Our analyses also indicate that large volcanic eruptions play a role as an lifier in the drought of 1631–1648 and caused the droughts of 1830–1853 and 1958–1976, which was identified by the model.
Timing and structure of early-Holocene climate anomalies inferred from north Chinese stalagmite records
Publisher: SAGE Publications
Date: 22-07-2021
DOI: 10.1177/09596836211033218
Abstract: In this paper, a new decadal resolution stalagmite δ 18 O record covering 10.4–6.5 ka BP from Kulishu cave in Beijing, north China is presented in combination with the published stalagmite δ 18 O record covering 10.4–14.0 ka BP in the same cave. Five significant monsoon collapses were identified around 11.5, 11.0, 10.0, 9.4, and 8.2 ka BP as well as three smaller ones around 10.3, 9.0, and 8.6 ka BP. The weak monsoon episodes around 8.6 and 8.2 ka BP form the two-step structure of the 8.2 ka event. All monsoon collapses, coeval with the cooling in northern high-latitude records, are correlated with Lakes Agassiz-Ojibway outbursts. Thus, our data support the idea of freshwater forcing of abrupt climate anomalies during the early Holocene. Nevertheless, the decreased irradiance together with freshwater outburst may account for the 9.2/9.3 ka event, which is expressed more significantly in low-latitude records.
Millennial- and orbital-scale changes in the East Asian monsoon over the past 224,000 years
Publisher: Springer Science and Business Media LLC
Date: 02-2008
DOI: 10.1038/NATURE06692
Abstract: High-resolution speleothem records from China have provided insights into the factors that control the strength of the East Asian monsoon. Our understanding of these factors remains incomplete, however, owing to gaps in the record of monsoon history over the past two interglacial-glacial cycles. In particular, missing sections have h ered our ability to test ideas about orbital-scale controls on the monsoon, the causes of millennial-scale events and relationships between changes in the monsoon and climate in other regions. Here we present an absolute-dated oxygen isotope record from Sanbao cave, central China, that completes a Chinese-cave-based record of the strength of the East Asian monsoon that covers the past 224,000 years. The record is dominated by 23,000-year-long cycles that are synchronous within dating errors with summer insolation at 65 degrees N (ref. 10), supporting the idea that tropical/subtropical monsoons respond dominantly and directly to changes in Northern Hemisphere summer insolation on orbital timescales. The cycles are punctuated by millennial-scale strong-summer-monsoon events (Chinese interstadials), and the new record allows us to identify the complete series of these events over the past two interglacial-glacial cycles. Their duration decreases and their frequency increases during glacial build-up in both the last and penultimate glacial periods, indicating that ice sheet size affects their character and pacing. The ages of the events are exceptionally well constrained and may thus serve as benchmarks for correlating and calibrating climate records.
The half-lives of uranium-234 and thorium-230
Publisher: Elsevier BV
Date: 08-2000
Complicated responses of stalagmite δ 13C to climate change during the last glaciation from Hulu Cave, Nanjing, China
Publisher: Springer Science and Business Media LLC
Date: 12-2005
DOI: 10.1360/04YD0140
Central Mediterranean rainfall varied with high northern latitude temperatures during the last deglaciation
Publisher: Springer Science and Business Media LLC
Date: 17-08-2022
DOI: 10.1038/S43247-022-00509-3
Abstract: Similarly to the effects of current climate change, the last deglaciation (Termination I) rapidly altered northern latitude temperatures and ice-sheet extent, as well as the Atlantic Meridional Overturning Circulation. However, it is still unclear how these changes propagated and impacted the central Mediterranean continental rainfall variability. This prevents a full understanding on how global warming will affect Mediterranean areas in the future. Here, we present a high-resolution reconstruction of rainfall changes in the central Mediterranean across Termination I, based on a novel δ 18 O time series from a southern Italian stalagmite. Across Termination I the availability of Atlantic moisture varied in response to northern latitude temperature increases (decreases) and ice-sheet decreases (increases), promoting a higher (lower) intensity of the Atlantic Meridional Overturning Circulation, and resulting in a relatively wetter (drier) climate in the Mediterranean. In the light of future warming, this study emphasises the role of high-latitude climate changes in causing rainfall variation in highly populated Mediterranean areas.
Preliminary Studies of Speleothem in Central Asia
Publisher: Wiley
Date: 12-2016
Quaternary ecological and geomorphic changes associated with rainfall events in presently semi‐arid northeastern Brazil
Publisher: Wiley
Date: 27-09-2004
DOI: 10.1002/JQS.876
Uranium-thorium-protactinium dating systematics
Publisher: Elsevier BV
Date: 11-1998
230Th and 231Pa on GEOTRACES GA03, the U.S. GEOTRACES North Atlantic transect, and implications for modern and paleoceanographic chemical fluxes
Publisher: Elsevier BV
Date: 06-2015
The East Asian summer monsoon variability over the last 145 years inferred from the Shihua Cave record, North China
Publisher: Springer Science and Business Media LLC
Date: 08-2017
DOI: 10.1038/S41598-017-07251-3
Abstract: The precipitation variability associated with the East Asian summer monsoon (EASM) has profound societal implications. Here, we use precisely dated and seasonally-resolved stalagmite oxygen isotope (δ 18 O) records from Shihua Cave, North China to reconstruct the EASM variability over the last 145 years. Our record shows a remarkable weakening of the EASM strength since the 1880s, which may be causally linked to the warming of the tropical Pacific and Indian Oceans. The δ 18 O record also exhibits a significant ~30-year periodicity, consistent with the instrumental, historical and proxy-based rainfall records from North China, plausibly driven by the Pacific Decadal Oscillation (PDO). Together, these observations imply that ~30-year periodicity is a persistent feature of the EASM, which remains significant with or without anthropogenic forcing. If indeed, the EASM rainfall in North China might decline significantly in the near future, which may affect millions of people in this region.
Persistent drying in the tropics linked to natural forcing
Publisher: Springer Science and Business Media LLC
Date: 14-07-2015
DOI: 10.1038/NCOMMS8627
Abstract: Approximately half of the world's population lives in the tropics, and future changes in the hydrological cycle will impact not just the freshwater supplies but also energy production in areas dependent upon hydroelectric power. It is vital that we understand the mechanisms rocesses that affect tropical precipitation and the eventual surface hydrological response to better assess projected future regional precipitation trends and variability. Paleo-climate proxies are well suited for this purpose as they provide long time series that pre-date and complement the present, often short instrumental observations. Here we present paleo-precipitation data from a speleothem located in Mesoamerica that reveal large multi-decadal declines in regional precipitation, whose onset coincides with clusters of large volcanic eruptions during the nineteenth and twentieth centuries. This reconstruction provides new independent evidence of long-lasting volcanic effects on climate and elucidates key aspects of the causal chain of physical processes determining the tropical climate response to global radiative forcing.
Distinct Permafrost Conditions Across the Last Two Glacial Periods in Midlatitude North America
Publisher: American Geophysical Union (AGU)
Date: 20-11-2019
DOI: 10.1029/2019GL083951
Abstract: During past glacial periods, extensive areas of North America were covered by permafrost. The timing and extent of these paleo‐permafrost conditions, however, remains ambiguous. Here we present a 250,000‐year record of speleothem growth from a midlatitude North American cave and report 141 U‐Th ages with hiatuses in growth that reflect the development of temporally continuous permafrost. Combined with U‐Th ages from other speleothem studies, we demonstrate that regional permafrost conditions occurred during both of the prior two glacial maxima but were markedly shorter in duration during the penultimate (Marine Isotope Stage 6, MIS 6) versus the last (MIS 2) glacial period. Notably, a network of sea surface temperatures indicates that mid‐ and low‐latitude temperatures were 0.9 °C ± 0.2 °C warmer during the culmination of MIS 6 versus MIS 2. Our results illustrate the importance of developing regional paleo‐permafrost records and highlight the sensitivity of permafrost conditions during glacial periods to relatively small differences in global‐scale temperature.
An Abrupt Shift in the Indian Monsoon 4000 Years Ago
Publisher: American Geophysical Union
Date: 28-03-2013
DOI: 10.1029/2012GM001207
Hydroclimate variability during the last 2700 years based on stalagmite multi-proxy records in the central-western Mediterranean
Publisher: Elsevier BV
Date: 10-2021
High-precision and high-resolution carbonate 230Th dating by MC-ICP-MS with SEM protocols
Publisher: Elsevier BV
Date: 12-2012
A new speleothem record of the penultimate deglacial: Insights into spatial variability and centennial-scale instabilities of East Asian monsoon
Publisher: Elsevier BV
Date: 04-2019
A high-resolved record of the Asian Summer Monsoon from Dongge Cave, China for the past 1200 years
Publisher: Elsevier BV
Date: 08-2015
A High‐Resolution Speleothem Record of Marine Isotope Stage 11 as a Natural Analog to Holocene Asian Summer Monsoon Variations
Publisher: American Geophysical Union (AGU)
Date: 28-08-2019
DOI: 10.1029/2019GL083836
Mid-latitude interhemispheric hydrologic seesaw over the past 550,000 years
Publisher: Springer Science and Business Media LLC
Date: 30-03-2014
DOI: 10.1038/NATURE13076
Abstract: An interhemispheric hydrologic seesaw--in which latitudinal migrations of the Intertropical Convergence Zone (ITCZ) produce simultaneous wetting (increased precipitation) in one hemisphere and drying in the other--has been discovered in some tropical and subtropical regions. For instance, Chinese and Brazilian subtropical speleothem (cave formations such as stalactites and stalagmites) records show opposite trends in time series of oxygen isotopes (a proxy for precipitation variability) at millennial to orbital timescales, suggesting that hydrologic cycles were antiphased in the northerly versus southerly subtropics. This tropical to subtropical hydrologic phenomenon is likely to be an initial and important climatic response to orbital forcing. The impacts of such an interhemispheric hydrologic seesaw on higher-latitude regions and the global climate system, however, are unknown. Here we show that the antiphasing seen in the tropical records is also present in both hemispheres of the mid-latitude western Pacific Ocean. Our results are based on a new 550,000-year record of the growth frequency of speleothems from the Korean peninsula, which we compare to Southern Hemisphere equivalents. The Korean data are discontinuous and derived from 24 separate speleothems, but still allow the identification of periods of peak speleothem growth and, thus, precipitation. The clear hemispheric antiphasing indicates that the sphere of influence of the interhemispheric hydrologic seesaw over the past 550,000 years extended at least to the mid-latitudes, such as northeast Asia, and that orbital-timescale ITCZ shifts can have serious effects on temperate climate systems. Furthermore, our result implies that insolation-driven ITCZ dynamics may provoke water vapour and vegetation feedbacks in northern mid-latitude regions and could have regulated global climate conditions throughout the late Quaternary ice age cycles.
Evaluating model outputs using integrated global speleothem records of climate change since the last glacial
Publisher: Copernicus GmbH
Date: 09-08-2019
Abstract: Abstract. Although quantitative isotope data from speleothems has been used to evaluate isotope-enabled model simulations, currently no consensus exists regarding the most appropriate methodology through which to achieve this. A number of modelling groups will be running isotope-enabled palaeoclimate simulations in the framework of the Coupled Model Intercomparison Project Phase 6, so it is timely to evaluate different approaches to using the speleothem data for data–model comparisons. Here, we illustrate this using 456 globally distributed speleothem δ18O records from an updated version of the Speleothem Isotopes Synthesis and Analysis (SISAL) database and palaeoclimate simulations generated using the ECHAM5-wiso isotope-enabled atmospheric circulation model. We show that the SISAL records reproduce the first-order spatial patterns of isotopic variability in the modern day, strongly supporting the application of this dataset for evaluating model-derived isotope variability into the past. However, the discontinuous nature of many speleothem records complicates the process of procuring large numbers of records if data–model comparisons are made using the traditional approach of comparing anomalies between a control period and a given palaeoclimate experiment. To circumvent this issue, we illustrate techniques through which the absolute isotope values during any time period could be used for model evaluation. Specifically, we show that speleothem isotope records allow an assessment of a model's ability to simulate spatial isotopic trends. Our analyses provide a protocol for using speleothem isotope data for model evaluation, including screening the observations to take into account the impact of speleothem mineralogy on δ18O values, the optimum period for the modern observational baseline and the selection of an appropriate time window for creating means of the isotope data for palaeo-time-slices.
Trends and oscillations in the Indian summer monsoon rainfall over the last two millennia
Publisher: Springer Science and Business Media LLC
Date: 17-02-2015
DOI: 10.1038/NCOMMS7309
Abstract: Observations show that summer rainfall over large parts of South Asia has declined over the past five to six decades. It remains unclear, however, whether this trend is due to natural variability or increased anthropogenic aerosol loading over South Asia. Here we use stable oxygen isotopes in speleothems from northern India to reconstruct variations in Indian monsoon rainfall over the last two millennia. We find that within the long-term context of our record, the current drying trend is not outside the envelope of monsoon's oscillatory variability, albeit at the lower edge of this variance. Furthermore, the magnitude of multi-decadal oscillatory variability in monsoon rainfall inferred from our proxy record is comparable to model estimates of anthropogenic-forced trends of mean monsoon rainfall in the 21st century under various emission scenarios. Our results suggest that anthropogenic-forced changes in monsoon rainfall will remain difficult to detect against a backdrop of large natural variability.
High resolution stalagmite δ18O records over the past 1000 years from Dongge Cave in Guizhou
Publisher: Science China Press., Co. Ltd.
Date: 2005
DOI: 10.1360/04WD0268
Speleothem records decadal to multidecadal hydroclimate variations in southwestern Morocco during the last millennium
Publisher: Elsevier BV
Date: 10-2017
Abrupt change of Antarctic moisture origin at the end of Termination II
Publisher: Proceedings of the National Academy of Sciences
Date: 21-06-2010
Abstract: The deuterium excess of polar ice cores documents past changes in evaporation conditions and moisture origin. New data obtained from the European Project for Ice Coring in Antarctica Dome C East Antarctic ice core provide new insights on the sequence of events involved in Termination II, the transition between the penultimate glacial and interglacial periods. This termination is marked by a north–south seesaw behavior, with first a slow methane concentration rise associated with a strong Antarctic temperature warming and a slow deuterium excess rise. This first step is followed by an abrupt north Atlantic warming, an abrupt resumption of the East Asian summer monsoon, a sharp methane rise, and a CO 2 overshoot, which coincide within dating uncertainties with the end of Antarctic optimum. Here, we show that this second phase is marked by a very sharp Dome C centennial deuterium excess rise, revealing abrupt reorganization of atmospheric circulation in the southern Indian Ocean sector.
A 120-year seasonally resolved speleothem record of precipitation seasonality from southeastern China
Publisher: Elsevier BV
Date: 07-2021
Mid- to late Holocene Indian Ocean Monsoon variability recorded in four speleothems from Socotra Island, Yemen
Publisher: Elsevier BV
Date: 04-2013
The leading mode of Indian Summer Monsoon precipitation variability during the last millennium
Publisher: American Geophysical Union (AGU)
Date: 08-2011
DOI: 10.1029/2011GL047713
Orbital-to-millennial scale climate variability during Marine Isotope Stages 5 to 3 in northeast Iberia
Publisher: Elsevier BV
Date: 11-2019
Reconstruction of Holocene coupling between the South American Monsoon System and local moisture variability from speleothem δ18O and 87Sr/86Sr records
Publisher: Elsevier BV
Date: 04-2019
Antiphase response of the Indonesian–Australian monsoon to millennial-scale events of the last glacial period
Publisher: Springer Science and Business Media LLC
Date: 23-11-2022
DOI: 10.1038/S41598-022-21843-8
Abstract: Antiphase behaviour of monsoon systems in alternate hemispheres is well established at yearly and orbital scales in response to alternating sensible heating of continental landmasses. At intermediate timescales without a sensible heating mechanism both in-phase and antiphase behaviours of northern and southern hemisphere monsoon systems are recorded at different places and timescales. At present, there is no continuous, high resolution, precisely dated record of millennial-scale variability of the Indonesian–Australian monsoon during the last glacial period with which to test theories of paleomonsoon behaviour. Here, we present an extension of the Liang Luar, Flores, speleothem δ 18 O record of past changes in southern hemisphere summer monsoon intensity back to 55.7 kyr BP. Negative δ 18 O excursions (stronger monsoon) occur during Heinrich events whereas positive excursions (weaker monsoon) occur during Dansgaard-Oeschger interstadials—a first order antiphase relationship with northern hemisphere summer monsoon records. An association of negative δ 18 O excursions with speleothem growth phases in Liang Luar suggests that these stronger monsoons are related to higher rainfall amounts. However, the response to millennial-scale variability is inconsistent, including a particularly weak response to Heinrich event 3. We suggest that additional drivers such as underlying orbital-scale variability and drip hydrology influence the δ 18 O response.
Local and Regional Indian Summer Monsoon Precipitation Dynamics During Termination II and the Last Interglacial
Publisher: American Geophysical Union (AGU)
Date: 14-11-2019
DOI: 10.1029/2019GL083721
Abstract: To date Indian summer monsoon (ISM) dynamics have been assessed by changes in stalagmite δ 18 O. However, stalagmite δ 18 O is influenced by multiple environmental factors (e.g., atmospheric moisture transport, rainfall amount at the study site, and ISM seasonality), precluding simple and clear reconstructions of rainfall amount or variability. This study aims to disentangle these environmental factors by combining δ 18 O, δ 44 Ca, and elemental data from a stalagmite covering Termination II and the last interglacial from Mawmluh Cave, NE India, to produce a semiquantitative reconstruction of past ISM rainfall. We interpret δ 18 O as a mixed signal of rainfall source dynamics and rainfall amount and coupled δ 44 Ca and X/Ca ratios as indicators of local infiltration rate and prior calcite precipitation in the karst zone. The wettest conditions in our studied interval (135 and 100 kyrs BP BP = before present, with the present being 1950 CE) occurred during Marine Isotope Stage 5e. Our multiproxy data set suggests a likely change in seasonal distribution of Marine Isotope Stage 5e rainfall compared to the Holocene the wet season was longer with higher‐than‐modern dry season rainfall. Using the last interglacial as an analogue for future anthropogenic warming, our data suggest a more erratic ISM behavior in a warmer world.
Prostanthera (Lamiaceae) as a ‘Cradle of Incense’: Chemophenetics of Rare Essential Oils from Both New and Forgotten Australian ‘Mint Bush’ Species
Publisher: MDPI AG
Date: 13-11-2020
Abstract: The highly aromatic Australian mint bushes from the genus Prostanthera Labill. produce a high yield of essential oil on hydrodistillation. Together with its rich history, horticultural potential, iconic flowers, and aromatic leaves, it achieves high ornamental and culinary value. Species in the genus express highly erse and chemically unique essential oils that demonstrate intra- and inter-specific patterns that have inspired taxonomic reinterpretation for over a hundred years. Previous studies have conveyed that phenoplastic expression of volatiles creates chemotypes within taxa, adding complexity to chemophenetic exploration. The current study chemically characterised essential oils from 64 highly aromatic specimens, representative of 25 taxa, giving yields as high as % g/g. The chemical profiles of essential oils are erse, but generally include 1,8-cineole and signatory compounds such as sesquiterpene oxides, caryophyllene oxide, kessane and cis-dihydroagarofuran sesquiterpene alcohols, globulol, epiglobulol, maaliol, prostantherol, spathulenol and ledol and monoterpene derivatives of common scaffolds, borneol, bornyl acetate, bornanone, linalool and linalyl acetate. As in previous studies, analysis of chemical data confirms that the chemistry strongly agrees with taxonomic classifications. Importantly, as in classical taxonomy, the current chemical study complemented morphological analysis but conveys chemovariation, obscuring the taxonomic agreement. Nevertheless, variation within taxa may be due to environmental factors, meaning that cultivation of species in gardens will create different chemical profiles as compared to those published here.
Corrigendum to Quaternary glaciation and hydrologic variation in the South American tropics as reconstructed from the Lake Titicaca drilling project [Quaternary Research 68 (2007) 410–420]
Publisher: Cambridge University Press (CUP)
Date: 03-2008
Coupled atmosphere-ice-ocean dynamics during Heinrich Stadial 2
Publisher: Springer Science and Business Media LLC
Date: 04-10-2022
DOI: 10.1038/S41467-022-33583-4
Abstract: Our understanding of climate dynamics during millennial-scale events is incomplete, partially due to the lack of their precise phase analyses under various boundary conditions. Here we present nine speleothem oxygen-isotope records from mid-to-low-latitude monsoon regimes with sub-centennial age precision and multi-annual resolution, spanning the Heinrich Stadial 2 (HS2) — a millennial-scale event that occurred at the Last Glacial Maximum. Our data suggests that the Greenland and Antarctic ice-core chronologies require +320- and +400-year adjustments, respectively, supported by extant volcanic evidence and radiocarbon ages. Our chronological framework shows a synchronous HS2 onset globally. Our records precisely characterize a centennial-scale abrupt “tropical atmospheric seesaw” superimposed on the conventional “bipolar seesaw” at the beginning of HS2, implying a unique response/feedback from low-latitude hydroclimate. Together with our observation of an early South American monsoon shift at the HS2 termination, we suggest a more active role of low-latitude hydroclimate dynamics underlying millennial events than previously thought.
Holocene moisture changes in western China, Central Asia, inferred from stalagmites
Publisher: Elsevier BV
Date: 02-2017
The “Hockey Stick” Imprint in Northwest African Speleothems
Publisher: American Geophysical Union (AGU)
Date: 08-09-2021
DOI: 10.1029/2021GL094232
Abstract: We present absolutely dated speleothem δ 18 O records spanning the past ∼1.5 kyr, which provide new evidence of the transmission of an anthropogenic signal to natural climatic archives in NW Africa. Combined with three other speleothem δ 18 O records from SW Morocco, the results indicate unprecedentedly dry conditions during the 20th century, which developed more rapidly than those during the Medieval Climate Anomaly (900–1350 CE), likely due to rising atmospheric CO 2 levels. The 20th century drying evident in the speleothem records is consistent with the “Hockey Stick” pattern of increasing temperatures due to global warming. We demonstrate that this rapid drying is linked to warmer sea surface temperatures (SSTs) over the Azores High region, and cooler local SSTs off the coast of NW Africa. These changes intensified the Canary Current Upwelling, which promoted increased biological productivity in the surface water and enhanced the coastal fishing industry in Morocco.
Mid-Holocene drying of the U.S. Great Basin recorded in Nevada speleothems
Publisher: Elsevier BV
Date: 11-2015
Radiometric, isotopic, and petrographic evidence of changing interglacials over the past 550,000 years from six stalagmites from the Serra do Courel in the Cordillera Cantábrica of northwestern Spain
Publisher: Elsevier BV
Date: 2017
Pre‐Industrial (1750–1850 CE) Cold Season Warmth in Northeastern China
Publisher: American Geophysical Union (AGU)
Date: 24-05-2023
DOI: 10.1029/2023GL103591
Abstract: Contrary to global warming projections, northern mid‐latitude continents have suffered from an increased frequency of unusually cold winters during the last few decades. However, a lack of longer‐term cold‐season temperature records from mid‐latitudes h ers our understanding of the forcing mechanisms of this temperature variability. Here we report a Group 1 alkenone‐based high‐resolution record of cold‐season temperatures extending to the pre‐industrial era (since 1700 CE) from Lake Luming in northeastern China. By comparing with the instrumental and historical records in the region, we verify the high efficacy of Group 1 alkenones as recorders of cold‐season temperature variability. Our record shows pre‐industrial warmth between 1750 and 1850 CE relative to anthropogenic industrial period (since 1850 CE), which is largely driven by variability of the Arctic Oscillation, with a negligible contribution from anthropogenic greenhouse‐gas forcing. Our results highlight the importance of internal atmospheric circulation in driving cold‐season temperatures in northeastern China.
A +20 m middle Pleistocene sea-level highstand (Bermuda and the Bahamas) due to partial collapse of Antarctic ice
Publisher: Geological Society of America
Date: 1999
Direct Determination of the Timing of Sea Level Change During Termination II
Publisher: American Association for the Advancement of Science (AAAS)
Date: 11-01-2002
Abstract: An outcrop within the last interglacial terrace on Barbados contains corals that grew during the penultimate deglaciation, or Termination II. We used combined 230 Th and 231 Pa dating to determine that they grew 135.8 ± 0.8 thousand years ago, indicating that sea level was 18 ± 3 meters below present sea level at the time. This suggests that sea level had risen to within 20% of its peak last-interglacial value by 136 thousand years ago, in conflict with Milankovitch theory predictions. Orbital forcing may have played a role in the deglaciation, as may have isostatic adjustments due to large ice sheets. Other corals in the same outcrop grew during oxygen isotope (δ 18 O) substage 6e, indicating that sea level was 38 ± 5 meters below present sea level, about 168.0 thousand years ago. When compared to the δ 18 O signal in the benthic V19-30/V19-28 record at that time, the coral data extend to the previous glacial cycle the conclusion that deep-water temperatures were colder during glacial periods.
Paleogeodetic records of seismic and aseismic subduction from central Sumatran microatolls, Indonesia
Publisher: American Geophysical Union (AGU)
Date: 04-2004
DOI: 10.1029/2003JB002398
Quaternary rainfall variability is governed by insolation in northern China and ice-sheet forcing in the South
Publisher: Springer Science and Business Media LLC
Date: 04-01-2023
DOI: 10.1038/S43247-022-00670-9
Abstract: Quaternary Asian low-latitude hydroclimate cyclicity has long been attributed to insolation forcing, in contrast to the dominant ice-sheet and CO 2 controls identified in mid-high-latitude regions. However, debates exist regarding these rainfall variations and forcings due to inconsistent reconstructions and simulations. Here, by combining rainfall proxy records with multi-model simulations, dominant 23 ka rainfall cycle in northern China and 100 ka rainfall cycle in southern China and Southeast Asia were found. We propose that rainfall mainly occurs in summer in the north, primarily driven by insolation. Rainfall in the south is largely forced by high-latitude ice sheets, with enhanced spring and autumn rainfall in southern China and weakened rainfall in western Maritime Continent during glacial periods. This study highlights the seasonal contributions to orbital-scale rainfall changes, and sheds light on the Asian hydroclimate conditions associated with high-low-latitude climate interactions.
Lacustrine cave carbonates: Novel archives of paleohydrologic change in the Bonneville Basin (Utah, USA)
Publisher: Elsevier BV
Date: 10-2012
Seasonal and interannual variability of the Mid-Holocene East Asian monsoon in coral δ18O records from the South China Sea
Publisher: Elsevier BV
Date: 08-2005
A global context for megadroughts in monsoon Asia during the past millennium
Publisher: Elsevier BV
Date: 2011
Replacement Times of a Spectrum of Elements in the North Atlantic Based on Thorium Supply
Publisher: American Geophysical Union (AGU)
Date: 09-2018
DOI: 10.1029/2017GB005839
North Atlantic Ice‐Rafting, Ocean and Atmospheric Circulation During the Holocene: Insights From Western Mediterranean Speleothems
Publisher: American Geophysical Union (AGU)
Date: 03-07-2019
DOI: 10.1029/2019GL082405
Abstract: In this study, we present a Holocene rainfall index based on three high‐resolution speleothem records from the Western Mediterranean, a region under the influence of the westerly winds belt modulated by the North Atlantic Oscillation (NAO). On centennial to millennial timescales, we show that the North Atlantic ice‐rafting events were likely associated with negative NAO‐like conditions during the Early Holocene and the Late Holocene. However, our data reveal that this is not clearly the case for the mid‐Holocene ice‐rafting events, during which we also show evidence of positive NAO‐like patterns from other paleo‐oceanographic and paleo‐atmospheric data. Hence, contradictory mechanisms involving prolonged periods of both north and south shifts of the westerly winds belt (resembling positive and negative NAO‐like patterns) might at least partially trigger or lify the ice‐rafting events and the slowdown of the Atlantic Meridional Overturning Circulation.
Direct measurements of deglacial monsoon strength in a Chinese stalagmite
Publisher: Geological Society of America
Date: 06-2015
DOI: 10.1130/G36612.1
Timing and duration of the East Asian summer monsoon maximum during the Holocene based on stalagmite data from North China
Publisher: SAGE Publications
Date: 25-06-2018
Abstract: We present a continuous C-O isotope series that shows the detailed variability of East Asian summer monsoon (EASM) since 11.0 ka BP. The series is based on two stalagmites, namely, DSY1 and LM2, which were, respectively, obtained from Dongshiya and Laomu caves. The δ 18 O profiles of stalagmite excurse negatively in early Holocene and gradually become positive after around 6.9 ka BP, tracking the change in Northern Hemisphere summer insolation. Moreover, the ‘early-Holocene maximum’ supported by stalagmite δ 18 O records differs from the ‘mid-Holocene maximum’ indicated by geological archives, such as lake sediments and loess. This difference may be caused by different definition indicators of monsoon intensity. Stalagmite δ 18 O is relative to EASM intensity, but irrelative to precipitation in the East Asian monsoon region. The time intervals of EASM maximum and Holocene climatic optimum are desynchronized, which is confirmed by the variation in the stalagmite δ 13 C series. Stalagmite δ 13 C and δ 18 O have different variation tendencies. The tendency of δ 13 C in early mid-Holocene was generally light, but it was discontinuity and disrupted by rapid positive shift between 8.2 and 7.7 ka BP. We conclude that a rapid shift of about 8 ka BP is a turning point, before and after which δ 13 C acquires different controlling factors. Stalagmite δ 13 C showed no signs of positive excurse in late Holocene but it exhibited another characteristic, namely, millennial time scale oscillations. The few changes in stalagmite δ 13 C is attributed to weakened insolation during summer in the northern hemisphere, which leads to low evaporation rate, thereby modulating effective humidity change. The edge of the seasonal monsoonal front in northern China during monsoon recession is sensitive to the rain belt and causes the δ 13 C of the stalagmite to fluctuate greatly. This phenomenon shows that the climate in the study area is unstable in the late Holocene
Evolution of the Asian summer monsoon during Dansgaard/Oeschger events 13–17 recorded in a stalagmite constrained by high-precision chronology from southwest China
Publisher: Cambridge University Press (CUP)
Date: 06-06-2017
DOI: 10.1017/QUA.2017.22
Abstract: A stalagmite with high 238 U content from Yangkou Cave, China, revealed the evolution of the Asian summer monsoon (ASM) between 49.1 and 59.5 ka, and the δ 18 O values recorded Dansgaard/Oeschger (D/O) events 13–17. The Yangkou record shows a relatively gradual transition into the D/O 14 and 16 events. The discrepancy between the abrupt and gradual transitions of D/O 14 in the records from northern and southern China, respectively, suggests different responses of the ASM to climate changes in the high northern latitudes. The higher resolution δ 18 O record and more precise 230 Th dating indicate that the timing of D/O 14 and 17 in the Hulu records at 53 and 58 ka should be shifted to 54.3 and 59 ka, respectively. The gradual strengthening of the ASM at the onsets of D/O 16 and 14 in our record is different from the abrupt temperature rise in the northern high latitudes. Some other factors must contribute to this relatively gradual ASM change in southern China, but the actual reason is still unknown.
High-resolution summer precipitation variations in the western Chinese Loess Plateau during the last glacial
Publisher: Springer Science and Business Media LLC
Date: 27-09-2013
DOI: 10.1038/SREP02785
Abstract: We present a summer precipitation reconstruction for the last glacial (LG) on the western edge of the Chinese Loess Plateau (CLP) using a well-dated organic carbon isotopic dataset together with an independent modern process study results. Our results demonstrate that summer precipitation variations in the CLP during the LG were broadly correlated to the intensity of the Asian summer monsoon (ASM) as recorded by stalagmite oxygen isotopes from southern China. During the last deglaciation, the onset of the increase in temperatures at high latitudes in the Northern Hemisphere and decline in the intensity of the East Asia winter monsoon in mid latitudes was earlier than the increase in ASM intensity and our reconstructed summer precipitation in the western CLP. Quantitative reconstruction of a single paleoclimatic factor provides new insights and opportunities for further understanding of the paleoclimatic variations in monsoonal East Asia and their relation to the global climatic system.
A severe drought during the last millennium in East Java, Indonesia
Publisher: Elsevier BV
Date: 11-2013
Modern aragonite formation at near-freezing conditions in an alpine cave, Carnic Alps, Austria
Publisher: Elsevier BV
Date: 10-2016
Evaluating agricultural bet‐hedging strategies in the Kona Field System: New high‐precision 230Th/U and 14C dates and plant microfossil data from Kealakekua, Hawai‘i Island
Publisher: Wiley
Date: 21-11-2016
DOI: 10.1002/ARCO.5121
Chinese stalagmite paleoclimate researches: A review and perspective
Publisher: Springer Science and Business Media LLC
Date: 19-09-2019
Reconstructing the western boundary variability of the Western Pacific Subtropical High over the past 200 years via Chinese cave oxygen isotope records
Publisher: Springer Science and Business Media LLC
Date: 21-09-2018
Lipid biomarkers in Lake Wudalianchi record abrupt environmental changes from the volcanic eruption in 1776
Publisher: Elsevier BV
Date: 02-2022
New speleothem data from Molinos and Ejulve caves reveal Holocene hydrological variability in northeast Iberia
Publisher: Cambridge University Press (CUP)
Date: 13-07-2017
DOI: 10.1017/QUA.2017.39
Abstract: New speleothem records from northeastern Iberian caves provide data to explore the climatic patterns during the Holocene. We present δ 13 C and Mg/Ca from three speleothems from two different caves located in the Iberian Range allowing replication of the climatic signal for several millennia. Through the integration of those stalagmites covering since the Holocene onset to 2 ka, the early Holocene (11.7–8.5 ka) appears as the wettest interval. A marked change towards aridity is observed during the middle Holocene (8.5–4.8 ka) and an increase of humidity afterwards (4.8–2 ka). This three-part pattern, contrasting with other Iberian sequences, seems to be associated with the different role that seasonality has played in the response of different proxies (or records) to changes in water availability. Interpreting our speleothem records as changes in winter-spring precipitation along the Holocene allows reconciling previous data on hydrological variability from the western Mediterranean borderlands.
A tropical speleothem record of glacial inception, the South American Summer Monsoon from 125 to 115 ka
Publisher: Copernicus GmbH
Date: 23-06-2015
Abstract: Abstract. Relatively few marine or terrestrial paleoclimate studies have focused on glacial inception, the transition from an interglacial to a glacial climate state. As a result, neither the timing and structure of glacial inception nor the spatial pattern of glacial inception in different parts of the world is well known. Here we present results of a study of a speleothem from the Peruvian Andes that records changes in the intensity of South American Summer Monsoon (SASM) rainfall over the period from 125 to 115 ka. The results show that late in the last interglacial period, at 123 ka, SASM rainfall decreased, perhaps in response to a decrease in temperature and ice cover in the high northern latitudes and associated changes in atmospheric circulation. Then at 120.8 ka, a rapid increase in SASM rainfall marks the end of the last interglacial. After a more gradual increase between 120 and 117 ka, a second abrupt increase occurs at 117 ka. This pattern of change is mirrored to a remarkable degree by changes in the East Asian Monsoon. It is interpreted to reflect both a long-term gradual response of the monsoons to orbitally driven insolation changes and to rapid changes in Northern Hemisphere ice volume and temperature. Both monsoon systems are close to their full glacial conditions by 117 ka, before any significant decrease in atmospheric CO2.
Unexpected cold season warming during the Little Ice Age on the northeastern Tibetan Plateau
Publisher: Springer Science and Business Media LLC
Date: 26-05-2023
DOI: 10.1038/S43247-023-00855-W
Abstract: There is a general agreement that Northern Hemisphere temperatures have cooled over the past two millennia, culminating in the Little Ice Age. However, this understanding partly relies on the compilation of existing proxy records, the majority of which carry a warm season bias such that there is an underrepresentation of cold-season temperatures. Here we report a unique cold-season temperature record based on the alkenone paleothermometer from the northeastern Tibetan Plateau that spans the last two millennia. In contrast to the regional- and hemisphere-scale summer cooling, our reconstruction shows a long-term warming through the Medieval Climate Anomaly into Little Ice Age. We attribute these opposing temperature trends to combined effects of seasonally ergent insolation and North Atlantic subpolar gyre circulation. Our study indicates that the cold season during the Little Ice Age was not the coldest period of the last two millennia at least on the northeastern Tibetan Plateau.
Distinct Holocene precipitation trends over arid Central Asia and linkages to westerlies and Asian monsoon
Publisher: Elsevier BV
Date: 08-2021
Indian summer monsoon variations during the Younger Dryas as revealed by a laminated stalagmite record from the Tibetan Plateau
Publisher: Elsevier BV
Date: 02-2022
Paleoclimatic and paleoenvironmental changes in Amazonian lowlands over the last three millennia
Publisher: Elsevier BV
Date: 03-2022
Chronostratigraphy and lake-level changes of Laguna Cari-Laufquén, Río Negro, Argentina
Publisher: Cambridge University Press (CUP)
Date: 11-2011
DOI: 10.1016/J.YQRES.2011.07.002
Abstract: Evidence from shoreline and deep-lake sediments show Laguna Cari-Laufquén, located at 41°S in central Argentina, rose and fell repeatedly during the late Quaternary. Our results show that a deep ( 38 m above modern lake level) lake persisted from no later than 28 ka to 19 ka, with the deepest lake phase from 27 to 22 ka. No evidence of highstands is found after 19 ka until the lake rose briefly in the last millennia to 12 m above the modern lake, before regressing to present levels. Laguna Cari-Laufquén broadly matches other regional records in showing last glacial maximum (LGM) highstands, but contrasts with sub-tropical lake records in South America where the hydrologic maximum occurred during deglaciation (17–10 ka). Our lake record from Cari-Laufquén mimics that of high-latitude records from the Northern Hemisphere. This points to a common cause for lake expansions, likely involving some combination of temperature depression and intensification of storminess in the westerlies belt of both hemispheres during the LGM.
Reply to Stuchlík et al.: The Younger Dryas onset at 12.87 ky B.P. is still justified if the Laacher See eruption is considered
Publisher: Proceedings of the National Academy of Sciences
Date: 18-01-2021
Authigenic carbonates from seeps on the northern continental slope of the South China Sea: New insights into fluid sources and geochronology
Publisher: Elsevier BV
Date: 05-2013
The earliest unequivocally modern humans in southern China
Publisher: Springer Science and Business Media LLC
Date: 10-2015
DOI: 10.1038/NATURE15696
Abstract: The hominin record from southern Asia for the early Late Pleistocene epoch is scarce. Well-dated and well-preserved fossils older than ∼45,000 years that can be unequivocally attributed to Homo sapiens are lacking. Here we present evidence from the newly excavated Fuyan Cave in Daoxian (southern China). This site has provided 47 human teeth dated to more than 80,000 years old, and with an inferred maximum age of 120,000 years. The morphological and metric assessment of this s le supports its unequivocal assignment to H. sapiens. The Daoxian s le is more derived than any other anatomically modern humans, resembling middle-to-late Late Pleistocene specimens and even contemporary humans. Our study shows that fully modern morphologies were present in southern China 30,000-70,000 years earlier than in the Levant and Europe. Our data fill a chronological and geographical gap that is relevant for understanding when H. sapiens first appeared in southern Asia. The Daoxian teeth also support the hypothesis that during the same period, southern China was inhabited by more derived populations than central and northern China. This evidence is important for the study of dispersal routes of modern humans. Finally, our results are relevant to exploring the reasons for the relatively late entry of H. sapiens into Europe. Some studies have investigated how the competition with H. sapiens may have caused Neanderthals' extinction (see ref. 8 and references therein). Notably, although fully modern humans were already present in southern China at least as early as ∼80,000 years ago, there is no evidence that they entered Europe before ∼45,000 years ago. This could indicate that H. neanderthalensis was indeed an additional ecological barrier for modern humans, who could only enter Europe when the demise of Neanderthals had already started.
Seasonality of precipitation recorded in a modern (1907–2008) annually laminated stalagmite from central China
Publisher: Elsevier BV
Date: 08-2021
The simulated climate of the Last Glacial Maximum and insights into the global carbon cycle
Publisher: Copernicus GmbH
Date: 15-01-2016
DOI: 10.5194/CP-12-1-2016
Abstract: Abstract. Middle Holocene cultures have been widely studied around the Eastern-Mediterranean basin in the last 30 years and past cultural activities have been commonly linked with regional climate changes. However, in many cases such linkage is equivocal, in part due to existing climatic evidence that has been derived from areas outside the distribution of ancient settlements, leading to uncertainty from complex spatial heterogeneity in both climate and demography. A few high-resolution well-dated paleoclimate records were recently established using speleothems in the Central and Eastern-Mediterranean basin, however, the scarcity of such records in the western part of the Mediterranean prevents us from correlating past climate evolutions across the basin and deciphering climate–culture relation at fine timescales. Here we report the first decadal-resolved Mid-Holocene climate proxy records from the Western-Mediterranean basin based on the stable carbon and oxygen isotopes analyses of two U/Th dated stalagmites from the Gueldaman GLD1 Cave in Northern Algeria. Comparison of our records with those from Italy and Israel reveals synchronous (multi) centennial dry phases centered at ca. 5600, ca. 5200 and ca. 4200 yr BP across the Mediterranean basin. New calibrated radiocarbon dating constrains reasonably well the age of rich anthropogenic deposits (e.g., faunal remains, pottery, charcoal) excavated inside the cave, which allows the comparison between in situ evidence of human occupation and of climate change. This approach shows that the timing of a prolonged drought at ca. 4400–3800 yr BP blankets the onset of cave abandonment shortly after ca. 4403 cal yr BP, supporting the hypothesis that a climate anomaly may have played a role in this cultural disruption.
An evaluation of quantitative reconstruction of past precipitation records using coral skeletal Sr/Ca and δ18O data
Publisher: Elsevier BV
Date: 09-2005
Climate on the southern Black Sea coast during the Holocene: implications from the Sofular Cave record
Publisher: Elsevier BV
Date: 09-2011
Climate dynamics during the penultimate glacial period recorded in a speleothem from Kanaan Cave, Lebanon (central Levant)
Publisher: Cambridge University Press (CUP)
Date: 25-04-2018
DOI: 10.1017/QUA.2018.18
Abstract: Little is known about terrestrial climate dynamics in the Levant during the penultimate interglacial-glacial period. To decipher the palaeoclimatic history of the Marine Oxygen Isotope Stage (MIS) 6 glacial period, a well-dated stalagmite (~194 to ~154 ka) from Kanaan Cave on the Mediterranean coast in Lebanon was analyzed for its petrography, growth history, and stable isotope geochemistry. A resolved climate record has been recovered from this precisely U–Th dated speleothem, spanning the late MIS 7 and early MIS 6 at low resolution and the mid–MIS 6 at higher resolution. The stalagmite grew discontinuously from ~194 to ~163 ka. More consistent growth and higher growth rates between ~163 and ~154 ka are most probably linked to increased water recharge and thus more humid conditions. More distinct layering in the upper part of the speleothem suggests strong seasonality from ~163 ka to ~154 ka. Short-term oxygen and carbon isotope excursions were found between ~155 and ~163 ka. The inferred Kanaan Cave humid intervals during the mid–MIS 6 follow variations of pollen records in the Mediterranean basins and correlate well with the synthetic Greenland record and East Asian summer monsoon interstadial periods, indicating short warm/wet periods similar to the Dansgaard-Oeschger events during MIS 4–3 in the eastern Mediterranean region.
Uranium-series coral ages from the US Atlantic Coastal Plain–the “80ka problem” revisited
Publisher: Elsevier BV
Date: 2004
A Speleothem Record of Younger Dryas Cooling, Klamath Mountains, Oregon, USA
Publisher: Cambridge University Press (CUP)
Date: 09-2005
DOI: 10.1016/J.YQRES.2005.06.008
Abstract: A well-dated δ 18 O record in a stalagmite from a cave in the Klamath Mountains, Oregon, with a s ling interval of 50 yr, indicates that the climate of this region cooled essentially synchronously with Younger Dryas climate change elsewhere in the Northern Hemisphere. The δ 18 O record also indicates significant century-scale temperature variability during the early Holocene. The δ 13 C record suggests increasing biomass over the cave through the last deglaciation, with century-scale variability but with little detectable response of vegetation to Younger Dryas cooling.
Characterizing the Eemian-Weichselian transition in northwestern Europe with three multiproxy speleothem archives from the Belgian Han-sur-Lesse and Remouchamps cave systems
Publisher: Elsevier BV
Date: 03-2019
Little Ice Age wetting of interior Asian deserts and the rise of the Mongol Empire
Publisher: Elsevier BV
Date: 2016
High-resolution absolute-dated Indian Monsoon record between 53 and 36 ka from Xiaobailong Cave, southwestern China
Publisher: Geological Society of America
Date: 2006
DOI: 10.1130/G22567.1
Holocene changes in monsoon precipitation in the Andes of NE Peru based on δ18O speleothem records
Publisher: Elsevier BV
Date: 08-2016
High resolution characterization of the Asian Monsoon between 146,000 and 99,000 years B.P. from Dongge Cave, China and global correlation of events surrounding Termination II
Publisher: Elsevier BV
Date: 06-2006
The seasonality of east central North American precipitation based on three coeval Holocene speleothems from southern West Virginia
Publisher: Elsevier BV
Date: 07-2010
The Homo sapiens Cave hominin site of Mulan Mountain, Jiangzhou District, Chongzuo, Guangxi with emphasis on its age
Publisher: Springer Science and Business Media LLC
Date: 11-2009
Variable North Pacific influence on drought in southwestern North America since AD 854
Publisher: Springer Science and Business Media LLC
Date: 07-07-2013
DOI: 10.1038/NGEO1862
Historic 1771 Meiwa tsunami confirmed by high‐resolution U/Th dating of massive Porites coral boulders at Ishigaki Island in the Ryukyus, Japan
Publisher: American Geophysical Union (AGU)
Date: 06-2010
DOI: 10.1029/2009GC002893
Stable isotope and trace element investigation of two contemporaneous annually-laminated stalagmites from northeastern China surrounding the "8.2 ka event"
Publisher: Copernicus GmbH
Date: 10-10-2012
Abstract: Abstract. The prominent "8.2 ka event" was well documented in the Greenland ice cores. It remains unclear, however, about its duration, structure and forcing mechanism at low- to mid-latitude regions. Here we use the physical and geochemical data of stalagmites from the Nuanhe Cave in Liaoning Province, northeastern China, to reconstruct a detailed history of East Asian monsoons covering the entire duration of the event. High-resolution chronologies of two contemporaneous stalagmites, each consisting of at least 770 yr annual growth bands, were established by calibrating and anchoring the floating band-counting ages against five high-precision 230Th dates. Two oxygen isotope profiles replicate each other on annual-decadal timescales despite their difference in growth rates, indicating that the δ18O variability has a climatic origin largely associated with changes in the rainfall δ18O from the West Pacific during summer season. A signal from the "8.2ka event" was faint in our δ18O records, not as significant as Indian monsoon dominated stalagmite δ18O records from Qunf in Oman and Dongge in Southern China. However, our δ13C and Ba/Ca profiles, as indicators of local environmental changes, provide strong support for a climate reversal centred at 8.2 ka BP, which is likely controlled by winter monsoon circulations via the westerly winds associated with North Atlantic climate. Therefore, we concluded that the winter- and summer-Asian monsoons responded independently to the high northern latitude climate.
Adolescent substance use and educational attainment: An integrative data analysis comparing cannabis and alcohol from three Australasian cohorts
Publisher: Elsevier BV
Date: 11-2015
DOI: 10.1016/J.DRUGALCDEP.2015.08.034
Abstract: The relative contributions of cannabis and alcohol use to educational outcomes are unclear. We examined the extent to which adolescent cannabis or alcohol use predicts educational attainment in emerging adulthood. Participant-level data were integrated from three longitudinal studies from Australia and New Zealand (Australian Temperament Project, Christchurch Health and Development Study, and Victorian Adolescent Health Cohort Study). The number of participants varied by analysis (N=2179-3678) and were assessed on multiple occasions between ages 13 and 25. We described the association between frequency of cannabis or alcohol use prior to age 17 and high school non-completion, university non-enrolment, and degree non-attainment by age 25. Two other measures of alcohol use in adolescence were also examined. After covariate adjustment using a propensity score approach, adolescent cannabis use (weekly+) was associated with 1½ to two-fold increases in the odds of high school non-completion (OR=1.60, 95% CI=1.09-2.35), university non-enrolment (OR=1.51, 95% CI=1.06-2.13), and degree non-attainment (OR=1.96, 95% CI=1.36-2.81). In contrast, adjusted associations for all measures of adolescent alcohol use were inconsistent and weaker. Attributable risk estimates indicated adolescent cannabis use accounted for a greater proportion of the overall rate of non-progression with formal education than adolescent alcohol use. Findings are important to the debate about the relative harms of cannabis and alcohol use. Adolescent cannabis use is a better marker of lower educational attainment than adolescent alcohol use and identifies an important target population for preventive intervention.
Measurement of oxygen and hydrogen isotopic ratios of speleothem fluid inclusion water using Picarro
Publisher: Science China Press., Co. Ltd.
Date: 03-08-2020
DOI: 10.1360/TB-2020-0201
Application of Avaatech X-ray fluorescence core-scanning in Sr/Ca analysis of speleothems
Publisher: Springer Science and Business Media LLC
Date: 29-03-2019
Holocene winter climate variability in mid-latitude western North America
Publisher: Springer Science and Business Media LLC
Date: 27-11-2012
DOI: 10.1038/NCOMMS2222
Abstract: Water resources in western North America depend on winter precipitation, yet our knowledge of its sensitivity to climate change remains limited. Similarly, understanding the potential for future loss of winter snow pack requires a longer perspective on natural climate variability. Here we use stable isotopes from a speleothem in southwestern Oregon to reconstruct winter climate change for much of the past 13,000 years. We find that on millennial time scales there were abrupt transitions between warm-dry and cold-wet regimes. Temperature and precipitation changes on multi-decadal to century timescales are consistent with ocean-atmosphere interactions that arise from mechanisms similar to the Pacific Decadal Oscillation. Extreme cold-wet and warm-dry events that punctuated the Holocene appear to be sensitive to solar forcing, possibly through the influence of the equatorial Pacific on the winter storm tracks reaching the US Pacific Northwest region.
East Asian summer monsoon variations during the last deglaciation, recorded from a stalagmite at Linyi, northern China
Publisher: Elsevier BV
Date: 2018
Simulation of the Interdecadal Pacific Oscillation and its impacts on the climate over eastern China during the last millennium
Publisher: American Geophysical Union (AGU)
Date: 13-08-2015
DOI: 10.1002/2015JD023104
Multi-decadal to centennial hydro-climate variability and linkage to solar forcing in the Western Mediterranean during the last 1000 years
Publisher: Springer Science and Business Media LLC
Date: 28-11-2018
DOI: 10.1038/S41598-018-35498-X
Abstract: Here we present a new composite record from two well-dated speleothem records from two caves in Northern Morocco. The high-resolution record covers the last millennium allowing to detect multi-decadal to centennial periodicities. Over the industrial period, δ 18 O values of our speleothems are shown to be dominated by the main mode of decadal variability in the North Atlantic region: the North Atlantic Oscillation (NAO). Statistical analyses confirm the previously reported multi-decadal variability related to the influence of the Atlantic Multidecadal Oscillation (AMO) in the region. High power and persistent centennial-scale periodicities, similar to the Vries-Suess 200-year solar cycle, are observed as well. Indeed, comparison between solar activity reconstructions and our record confirms the in-phase relationship on centennial time-scales. Low δ 18 O values, and hence negative phases of NAO that bring precipitation towards the Western Mediterranean, are observed during well-known solar minima periods. The results are consistent with previous models which describe low irradiance as a trigger for southward shifts of precipitation-bearing westerlies during winter.
Medieval Climate Variability in the eastern Amazon-Cerrado regions and its archeological implications
Publisher: Springer Science and Business Media LLC
Date: 30-12-2019
DOI: 10.1038/S41598-019-56852-7
Abstract: The South American Monsoon System is responsible for the majority of precipitation in the continent, especially over the Amazon and the tropical savannah, known as ‘Cerrado’. Compared to the extensively studied subtropical and temperate regions the effect of the Medieval Climate Anomaly (MCA) on the precipitation over the tropics is still poorly understood. Here, we present a multiproxy paleoprecipitation reconstruction showing a consistent change in the hydrologic regime during the MCA in the eastern Amazon and ‘Cerrado’, characterized by a substantial transition from humid to drier conditions during the Early (925-1150 C.E.) to Late-MCA (1150-1350 C.E.). We compare the timing of major changes in the monsoon precipitation with the expansion and abandonment of settlements reported in the archeological record. Our results show that important cultural successions in the pre-Columbian Central Amazon, the transition from Paredão to Guarita phase, are in agreement with major changes in the hydrologic regime. Phases of expansion and, subsequent abandonment, of large settlements from Paredão during the Early to Late-MCA are coherent with a reduction in water supply. In this context we argue that the sustained drier conditions during the latter period may have triggered territorial disputes with Guarita leading to the Paredão demise.
Radiocarbon Calibration and Comparison to 50 Kyr BP with Paired 14C and 230Th Dating of Corals from Vanuatu and Papua New Guinea
Publisher: Cambridge University Press (CUP)
Date: 2004
DOI: 10.1017/S0033822200033063
Abstract: We calibrated portions of the radiocarbon time scale with combined 230 Th, 231 Pa, 14 C measurements of corals collected from Espiritu Santo, Vanuatu and the Huon Peninsula, Papua New Guinea. The new data map 14 C variations ranging from the current limit of the tree-ring calibration [11,900 calendar years before present (cal BP), Kromer and Spurk 1998, now updated to 12,400 cal B P, see Kromer et al., this issue], to the 14 C-dating limit of 50,000 cal BP, with detailed structure between 14 to 16 cal kyr BP and 19 to 24 cal kyr BP. S les older than 25,000 cal BP were analyzed with high-precision 231 Pa dating methods (Pickett et al. 1994 Edwards et al. 1997) as a rigorous second check on the accuracy of the 230 Th ages. These are the first coral calibration data to receive this additional check, adding confidence to the age data forming the older portion of the calibration. Our results, in general, show that the offset between calibrated and 14 C ages generally increases with age until about 28,000 cal BP, when the recorded 14 C age is nearly 6800 yr too young. The gap between ages before this time is less at 50,000 cal BP, the recorded 14 C age is 4600 yr too young. Two major 14 C-age plateaus result from a 130 drop in Δ 14 C between 14–15 cal kyr BP and a 700 drop in Δ 14 C between 22–25 cal kyr BP. In addition, a large atmospheric Δ 14 C excursion to values over 1000 occurs at 28 cal kyr BP. Between 20 and 10 cal kyr BP, a component of atmospheric Δ 14 C anti-correlates with Greenland ice δ 18 O, indicating that some portion of the variability in atmospheric Δ 14 C is related to climate change, most likely through climate-related changes in the carbon cycle. Furthermore, the 28-kyr excursion occurs at about the time of significant climate shifts. Taken as a whole, our data indicate that in addition to a terrestrial magnetic field, factors related to climate change have affected the history of atmospheric 14 C.
The Holocene Pulleniatina Minimum Event revisited: Geochemical and faunal evidence from the Okinawa Trough and upper reaches of the Kuroshio current
Publisher: Elsevier BV
Date: 05-2006
East Asian hydroclimate modulated by the position of the westerlies during Termination I.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 02-11-2018
Abstract: Speleothem oxygen isotope records have revolutionized our understanding of the paleo East Asian monsoon, yet there is fundamental disagreement on what they represent in terms of the hydroclimate changes. We report a multiproxy speleothem record of monsoon evolution during the last deglaciation from the middle Yangtze region, which indicates a wetter central eastern China during North Atlantic cooling episodes, despite the oxygen isotopic record suggesting a weaker monsoon. We show that this apparent contradiction can be resolved if the changes are interpreted as a lengthening of the Meiyu rains and shortened post-Meiyu stage, in accordance with a recent hypothesis. Model simulations support this interpretation and further reveal the role of the westerlies in communicating the North Atlantic influence to the East Asian climate.
Geochronology, sediment provenance, and fossil emplacement at Sumidouro Cave, a classic late Pleistocene/early Holocene Paleoanthropological site in eastern Brazil
Publisher: Wiley
Date: 2005
DOI: 10.1002/GEA.20081
Timing, Duration, and Transitions of the Last Interglacial Asian Monsoon
Publisher: American Association for the Advancement of Science (AAAS)
Date: 23-04-2004
Abstract: Thorium-230 ages and oxygen isotope ratios of stalagmites from Dongge Cave, China, characterize the Asian Monsoon and low-latitude precipitation over the past 160,000 years. Numerous abrupt changes in 18 O/ 16 O values result from changes in tropical and subtropical precipitation driven by insolation and millennial-scale circulation shifts. The Last Interglacial Monsoon lasted 9.7 ± 1.1 thousand years, beginning with an abrupt (less than 200 years) drop in 18 O/ 16 O values 129.3 ± 0.9 thousand years ago and ending with an abrupt (less than 300 years) rise in 18 O/ 16 O values 119.6 ± 0.6 thousand years ago. The start coincides with insolation rise and measures of full interglacial conditions, indicating that insolation triggered the final rise to full interglacial conditions.
Centennial- to decadal-scale monsoon precipitation variability in the semi-humid region, northern China during the last 1860 years: Records from stalagmites in Huangye Cave
Publisher: SAGE Publications
Date: 24-08-2010
Abstract: We developed a composite oxygen isotopic record of cave calcite for the last 1860 years based on three stalagmites from the Huangye Cave in eastern Gansu Province, northern China. The δ 18 O values reflect monsoon precipitation changes, with lower δ 18 O values representing higher precipitation and vice versa. Three intervals of high precipitation were identified at AD 138—450, AD 730—1200, and AD 1860—1960. Two intervals of low precipitation occurred at AD 1320—1410 and AD 1530—1860. The reconstructed monsoon precipitation variations correlate well with other records further east in the eastern Yellow River Basin, suggesting synchronous precipitation changes during the late Holocene in the semi-humid region of northern China on decadal to centennial scales. Peak periods of warfare in dynastic transition times, such as at AD 391—420, AD 601—630, AD 1111—1140, AD 1351—1380, and AD 1621—1650, correspond to sharp declines in precipitation or temperature in semi-humid northern China, indicating a strong connection between climatic and societal changes. Our study suggests that climatic deterioration in semi-humid northern China has played an important role in Chinese societal evolution.
A multimillennial climatic context for the megafaunal extinctions in Madagascar and Mascarene Islands
Publisher: American Association for the Advancement of Science (AAAS)
Date: 16-10-2020
Abstract: Human activities within the context of a drying trend triggered the megafaunal extinctions in Madagascar and Mascarene Islands.
Centennial-scale Asian Monsoon variability during the mid-Younger Dryas from Qingtian Cave, central China
Publisher: Cambridge University Press (CUP)
Date: 09-2013
DOI: 10.1016/J.YQRES.2013.06.009
Abstract: The regional climate correlation within the Northern Hemisphere in the cold/dry mid-Younger Dryas event (YD) remains elusive. A key to unraveling this issue is sufficient knowledge of the detailed climate variability at the low latitudes. Here we present a high-resolution (3-yr) δ 18 O record of an annually laminated stalagmite from central China that reveals a detailed Asian monsoon (AM) history from 13.36 to 10.99 ka. The YD in this record is expressed as three phases, characterized by gradual onsets but rapid ends. During the mid-YD, the AM variability exhibited an increasing trend superimposed by three centennial oscillations, well-correlated to changes in Greenland temperatures. These warming/wetting fluctuations show a periodicity of ~ 200 yr, generally in agreement with centennial changes in cosmogenic nuclides indicated by the 10 Be flux from the Greenland ice. This relationship implies that centennial-scale climate changes during the mid-YD are probably caused by solar output and rapidly transported over broad regions through atmosphere reorganization.
A data-model comparison pinpoints Holocene spatiotemporal pattern of East Asian summer monsoon
Publisher: Elsevier BV
Date: 06-2021
Corrigendum to “U–Th dating of lake sediments: Lessons from the 700 ka sediment record of lake Junín, Peru” [Quat. Sci. Rev. 244 (2020) 106422]
Publisher: Elsevier BV
Date: 11-2020
A 6000-year high-resolution climatic record from a stalagmite in Xiangshui Cave, Guilin, China
Publisher: SAGE Publications
Date: 07-2004
DOI: 10.1191/0959683604HL748RP
Abstract: Middle-to late-Holocene palaeoclimate change has been reconstructed at high resolution by the analysis of the carbon and oxygen isotopes from a thermal ionization mass spectrometric (TIMS) U/Th dated stalagmite from Xiangshui Cave, near Guilin, Guangxi Province, China. The carbon and oxygen isotopic records from the stalagmite suggest that changes in the Asian monsoon since the middle Holocene (6000 BP) can be ided into two periods: (1) an interval from 6000 to 3800 BP when a strong East Asian summer monsoon gradually weakened and climate was relatively warm and humid (2) a cool period from 3800 to 373 BP when the East Asian summer monsoon was relatively weak and the winter monsoon was probably relatively strong. This cooler interval was interspersed with a number of short warm periods. A This interpretation is largely based upon the general increase in 6180 values of the stalagmite between 6000 and 3800 BP and shifts in 6180 about a relatively heavy mean value between 3800 and 373 BP. The 6000 to 3800 BP trend is probably associated with decrease in precipitation and temperature subsequent to the mid-Holocene climatic optimum.
High-resolution stalagmite δ18O records of Asian monsoon changes in central and southern China spanning the MIS 3/2 transition
Publisher: Elsevier BV
Date: 09-2010
Intense hydrothermal scavenging of 230Th and 231Pa in the deep Southeast Pacific
Publisher: Elsevier BV
Date: 04-2018
Early-Holocene monsoon instability and climatic optimum recorded by Chinese stalagmites
Publisher: SAGE Publications
Date: 28-02-2019
Abstract: The timing and duration of the Holocene East Asian summer monsoon (EASM) maximum and the interpretation of Chinese stalagmite δ 18 O records have long been disputed. Notably, interpretations of Holocene EASM variations are frequently based on a single record or study area and are often contradictory. In this study, we conducted stable isotope analyses of four Holocene stalagmites from Chongqing, southwest China. The results reveal differences in the timing of the Holocene EASM maximum and to try to resolve the inconsistency we analyzed and statistically integrated a total of 16 Holocene stalagmite records from 14 caves in the EASM region. The resulting synthesized Holocene stalagmite δ 18 O (δ 18 O syn ) record is in agreement with other EASM records and confirms that stalagmite δ 18 O records are a valid indicator of EASM intensity, rather of local precipitation amount. The δ 18 O syn record shows that the EASM intensified rapidly from the onset of the early Holocene notably, however, there were distinct EASM oscillations in the early Holocene, consisting of three abrupt millennial-scale events. This indicates that, contrary to several previous interpretations, the early Holocene EASM was unstable. Subsequently, during 8–6 kyr BP, the EASM was relatively stable and strong, with the strongest monsoon occurring during 8–7 kyr BP. This evidence of a stable and strong mid-Holocene EASM in eastern China is in accord with the classical view of a mid-Holocene Optimum in China.
Improvements in 230Th dating, 230Th and 234U half-life values, and U–Th isotopic measurements by multi-collector inductively coupled plasma mass spectrometry
Publisher: Elsevier BV
Date: 06-2013
Coral record of reduced El Nino activity in the early 15th to middle 17th centuries
Publisher: Geological Society of America
Date: 19-10-2012
DOI: 10.1130/G33510.1
U concentration and 234 U/ 238 U of seawater from the Okinawa Trough and Indian Ocean using MC-ICPMS with SEM protocols
Publisher: Elsevier BV
Date: 11-2017
A new perspective on the hydroclimate variability in northern South America during the Little Ice Age
Publisher: American Geophysical Union (AGU)
Date: 11-2009
DOI: 10.1029/2009GL041051
A comparison of
U
/
T
h and rapid‐screen
14
C
dates from
Publisher:
American Geophysical Union (AGU)
Date:
03-2016
DOI:
10.1002/2015GC005893
Publisher: American Geophysical Union (AGU)
Date: 03-2016
DOI: 10.1002/2015GC005893
Implications for soil environment from uranium isotopes of stalagmites
Publisher: Science China Press., Co. Ltd.
Date: 2002
DOI: 10.1360/02TB9363
Carbon and oxygen isotope records and paleoclimate reconstruction (140–250 ka B.P.) from a stalagmite of Shuinan Cave, Guilin, China
Publisher: Springer Science and Business Media LLC
Date: 30-11-2005
Centennial-scale climatic changes in Central China during the Holocene climatic optimum
Publisher: Elsevier BV
Date: 11-2020
Onset and duration of transitions into Greenland Interstadials 15.2 and 14 in northern China constrained by an annually laminated stalagmite
Publisher: Springer Science and Business Media LLC
Date: 10-02-2016
DOI: 10.1038/SREP20844
Abstract: The onset and duration of abrupt transitions into Dansgaard-Oeschger (DO) events can be studied in detail in Greenland ice cores given the excellent relative uncertainty of its lamina-counting chronology. For other geological archives, however, the shorter intervals are not determined accurately due to lack of clear annual lamina. Here, we present an oxygen isotope record of a stalagmite with well-developed annual lamina from Xinglong Cave, northern China, covering DO 15 and 14. Except for the absence of Greenland Interstadial (GIS) 15.1, the pattern of this record strongly resembles that of Greenland ice cores on millennial scales as well as the detailed centennial-scale cooling excursions within GIS 14. Additionally, the transitions into GIS 15.2 and 14, constrained by lamina counting, lasted 74 and 27 yr, respectively, both of which are in excellent agreement with that of the NGRIP record on the GICC05 timescales (100 ± 6 and 20 ± 1 yr, respectively). The close coupling of abrupt climatic oscillations on millennial to decadal scales between Greenland and northern China implies a rapid atmospheric teleconnection between the North Atlantic and the East Asian Summer Monsoon regions, probably via the westerlies.
Shallow particulate organic carbon regeneration in the South Pacific Ocean
Publisher: Proceedings of the National Academy of Sciences
Date: 29-04-2019
Abstract: Plankton in the sunlit surface ocean photosynthesize, fixing dissolved CO 2 into particulate organic carbon (POC). This POC sinks and is respired, releasing CO 2 into subsurface waters that are sequestered from the atmosphere. The depth scale over which this regeneration happens strongly affects atmospheric CO 2 , but estimates to date have been sparse and challenging to interpret. We use a new geochemical method to determine POC regeneration depth scales at unprecedented resolution in the South Pacific Ocean, finding shallow regeneration in both oxygen-deficient zone and oligotrophic gyre settings. Our results imply decreased future ocean carbon storage due to gyre expansion and two opposing feedbacks to expanding oxygen-deficient zones, the net effects of which on ocean carbon storage require future research.
Le système karstique de Sprimont (Belgique). Holotype d’une spéléogenèse par fantômisation
Publisher: EDP Sciences
Date: 2018
DOI: 10.1051/BSGF/2017205
Abstract: Le système karstique de Sprimont est riche de phénomènes karstiques variés dans un contexte géologique bien défini : un synclinal de carbonates carbonifères entourés au nord, à l’est et au sud par des formations famenniennes imperméables. À l’ouest, l’Ourthe recoupe le synclinal perpendiculairement à son axe d’allongement dans le cadre d’un relief appalachien typique et constitue le niveau de base karstique. Le relief consiste en un vallon orienté est-ouest dont l’axe coïncide avec celui du synclinal. Les ruisseaux qui descendent des hauteurs imperméables vers le vallon se perdent après leur entrée dans le domaine calcaire. Ces ruisseaux confluent sous terre pour résurger au « Trou Bleu », unique résurgence du système, non loin du talweg de l’Ourthe. Le système compte de nombreuses grottes, de dimensions souvent décamétriques. Quelques-unes sont de plus grande leur, dont la grotte du « Noû Bleû » récemment découverte, qui est un regard sur la rivière souterraine à quelques dizaines de mètres en amont de la résurgence. Les carrières ont dévoilé en plus de erses grottes des phénomènes karstiques de type fantôme de roche. La karstogenèse de type fantôme de roche consiste en une altération modérée des carbonates produisant une séparation de phase. D’une part, la phase soluble comprend essentiellement le calcium, le magnésium, le bicarbonate et la silice colloïdale. Elle sort du système par la voie souterraine. D’autre part, une altérite résiduelle constitue la phase solide restante comprenant une partie des carbonates cinétiquement moins solubles comme la calcite sparitique et la dolomie pro parte , les insolubles comme les minéraux argileux, le quartz, et la matière organique. Cette phase solide évolue de façon isovolume lors d’une première étape et voit donc sa porosité augmenter, de même que sa fragilité mécanique. Cette première étape se déroule durant une période géologique où le potentiel hydrodynamique est très réduit, la fantômisation s’exerçant grâce à des circulations phréatiques très lentes mais chimiquement agressives. On obtient ainsi des volumes soit totalement circonscrits dans la masse rocheuse (pseudoendokarsts) soit sous forme de couloirs descendant du toit de la roche mère, remplis par l’altérite résiduelle. À Sprimont, la carrière du Coreux a dévoilé ces fantômes de roche. Durant une seconde phase, lorsqu’apparaît un potentiel hydrodynamique suite à une surrection et à l’incision des rivières, l’altérite peut être mécaniquement érodée par des circulations fluviatiles : les grottes « spéléologiques » se forment. Dans le site étudié, une cavité, la grotte « Nico », a été ouverte par l’avancée du front de la carrière. On y trouve une coupe sédimentaire montrant l’altérite résiduelle ravinée par des formations fluviatiles. Cet article décrit la coupe levée dans ces formations au travers de la lithostratigraphie, de la granulométrie et de la minéralogie des grains. La grotte « Nico » résulte de la coalescence de deux grottes superposées, le plancher rocheux séparant les deux cavités étant fantômisé et affaissé. Les parois et le sol sont des fantômes de roche dont l’altérite résiduelle est essentiellement formée de grains dolomitiques, tels les encrines dolomitisées. Les formations fluviatiles ravinent l’altérite suivant une surface chenalisante. Les grains sont constitués de grains remaniés d’altérite, calcite et dolomite, et d’une faible partie d’insolubles tels des grains de muscovite et de quartz en provenance des psammites famenniens. La série détritique est coiffée par un plancher stalagmitiques dont deux échantillons ont été datés de 53 851 ± 2493 et 61 542 ± 1235 ans B.P. ce qui situe l’érosion de l’altérite à une date relativement récente dans le Pléistocène supérieur. Ces phénomènes éclairent d’un jour nouveau la formation des grottes en Haute Belgique. L’évolution du karst de Sprimont trouve son origine dans un massif fantômisé partiellement érodé au cours de la surrection plio-quaternaire. L’apparition du potentiel hydrodynamique responsable de cette érosion trouve son origine dans les différences d’altitude entre pertes supérieures et résurgence à l’aval par enfoncement du niveau de base : la rivière Ourthe. Nous sommes confrontés à un holotype de spéléogenèse dans le cadre d’un relief appalachien. La grotte « Nico » et les phénomènes associés permettent de concevoir un modèle d’évolution des karsts de la Haute Belgique. Enfin, cet exemple montre aussi qu’une distinction claire peut être faite entre le terme karstogenèse qui englobe la fantômisation de celui de spéléogenèse qui ne concerne que le creusement des grottes spéléologiques par érosion mécanique de l’altérite résiduelle.
A possible Younger Dryas-type event during Asian monsoonal Termination 3
Publisher: Springer Science and Business Media LLC
Date: 09-2006
On the low-frequency component of the ENSO–Indian monsoon relationship: a paired proxy perspective
Publisher: Copernicus GmbH
Date: 11-04-2014
Abstract: Abstract. There are a number of clear ex les in the instrumental period where positive El Niño–Southern Oscillation (ENSO) events were coincident with a severely weakened Indian summer monsoon (ISM). ENSO's influence on ISM precipitation has therefore remained the centerpiece of various predictive schemes of ISM rainfall for over a century. The teleconnection between ISM precipitation and ENSO has undergone a protracted weakening since the late 1980s, suggesting the strength of ENSO's influence on ISM precipitation may vary on multidecadal timescales. The recent weakening has occurred despite the fact that the ENSO system has experienced variance levels during the latter part of the 20th century that are as high as any period in the past millennium. The recent change in the ENSO–ISM coupling has prompted questions as to whether this shift represents a natural mode of climate variability or a fundamental change in ENSO and/or ISM dynamics due to anthropogenic warming or aerosol impacts on the ISM. Here we place the 20th century ENSO–ISM relationship in a millennial context by assessing the phase relationship between the two systems across the time spectrum using a a series of high-resolution reconstructions of ENSO and the ISM from tree rings, speleothems and corals. The results from all the proxies suggest that in the high-frequency domain (5–15 yr), warm (cool) sea surface temperatures in the eastern tropical Pacific lead to a weakened (strengthened) monsoon. This finding is consistent with the observed relationship between the two systems during the instrumental period. However, in the multidecadal domain (30–90 yr) the phasing between the systems is reversed such that periods of strong monsoons were, in general, coincident with periods of enhanced ENSO variability. This result is counterintuitive to the expectation that enhanced ENSO variance favors an asymmetric increase in the frequency of El Niño events and therefore a weakened monsoon system. The finding implies that the prominent multidecadal variability that characterizes the last 1000 yr of the ISM is not likely attributable to multidecadal shifts in ENSO. If there is a continued trend towards enhanced ENSO variance in the coming decades, the results presented here do not suggest this will force a reduction in ISM precipitation.
Petrographic and isotopic evidence for Holocene long-term climate change and shorter-term environmental shifts from a stalagmite from the Serra do Courel of northwestern Spain, and implications for cl
Publisher: Elsevier BV
Date: 05-2011
Orbital and Millennial-Scale Precipitation Changes in Brazil from Speleothem Records
Publisher: Springer Netherlands
Date: 2009
Droughts and societal change: The environmental context for the emergence of Islam in late Antique Arabia.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 17-06-2022
Abstract: In Arabia, the first half of the sixth century CE was marked by the demise of Himyar, the dominant power in Arabia until 525 CE. Important social and political changes followed, which promoted the disintegration of the major Arabian polities. Here, we present hydroclimate records from around Southern Arabia, including a new high-resolution stalagmite record from northern Oman. These records clearly indicate unprecedented droughts during the sixth century CE, with the most severe aridity persisting between ~500 and 530 CE. We suggest that such droughts undermined the resilience of Himyar and thereby contributed to the societal changes from which Islam emerged.
Understanding Interannual Variations of the Local Rainy Season over the Southwest Indian Ocean
Publisher: Springer Science and Business Media LLC
Date: 04-09-2021
Seasonal and Inter-Annual Variations of Stable Isotopic Characteristics of Rainfall and Cave Water in Shennong Cave, Southeast China, and Its Paleoclimatic Implication
Publisher: Frontiers Media SA
Date: 14-12-2021
DOI: 10.3389/FEART.2021.794762
Abstract: Speleothem calcite stable oxygen isotope (δ 18 O C ) is one of the most widely used proxies in paleoclimate research, and understanding its seasonal-annual variability is very significant for palaeoclimate reconstruction. Five-year precipitation and karst cave water from 2016 to 2021 were monitored in Shennong cave, Jiangxi Province, Southeast China. The local meteoric water line (LMWL) is δD = 8.20 × δ 18 O + 13.34, which is similar to the global meteoric water line. The stable hydrogen and oxygen isotope (δD and δ 18 O) characteristics of precipitation and cave water were studied. δ 18 O and δD of precipitation and cave water show obvious seasonal variations. Lower precipitation δ 18 O and δD generally occur during summer and autumn compared with higher δ 18 O and δD values during winter and spring. Meanwhile, low precipitation δ 18 O values do not only appear in June–July when precipitation is the highest of the year but also appear in August–September when precipitation is limited. The back-trajectory analysis of monsoon precipitation moisture sources shows that the moisture uptake regions vary little on inter-annual scales the water vapor of rainfall in June–July comes from the South China Sea and the Bay of Bengal, while the moisture source in August–September is mainly from the West Pacific and local area. The El Niño-Southern Oscillation is an important factor affecting the value of δ 18 O by modulating the percentage of summer monsoon precipitation in the annual precipitation and moisture source. The relationship between amount-weighted monthly mean precipitation δ 18 O and Niño-3.4 index shows that the East Asian summer monsoon (EASM) intensifies during La Niña phases, resulting in more precipitation in monsoon season (May to September, MJJAS) and lower δ 18 O values, and vice versa during El Niño phases.
A high-resolution stalagmite O-C isotope record from Nanjing and its rapid response to climatic events
Publisher: Elsevier BV
Date: 2002
DOI: 10.1360/02TB9032
Palaeoclimate significance of speleothems in crystalline rocks: a test case from the Late Glacial and early Holocene (Vinschgau, northern Italy)
Publisher: Copernicus GmbH
Date: 16-03-2018
Abstract: Abstract. Partly coeval flowstones formed in fractured gneiss and schist were studied to test the palaeoclimate significance of this new type of speleothem archive on a decadal-to-millennial timescale. The s les encompass a few hundred to a few thousand years of the Late Glacial and the early Holocene. The speleothem fabric is primarily comprised of columnar fascicular optic calcite and acicular aragonite, both indicative of elevated Mg ∕ Ca ratios in the groundwater. Stable isotopes suggest that aragonite is more prone to disequilibrium isotope fractionation driven by evaporation and prior calcite/aragonite precipitation than calcite. Changes in mineralogy are therefore attributed to these two internal fracture processes rather than to palaeoclimate. Flowstones formed in the same fracture show similar δ18O changes on centennial scales, which broadly correspond to regional lacustrine δ18O records, suggesting that such speleothems may provide an opportunity to investigate past climate conditions in non-karstic areas. The shortness of overlapping periods in flowstone growth and the complexity of in-aquifer processes, however, render the establishment of a robust stacked δ18O record challenging.
Timing and structure of the Younger Dryas event and its underlying climate dynamics
Publisher: Proceedings of the National Academy of Sciences
Date: 08-09-2020
Abstract: The Younger Dryas (YD) was an ∼1,300-y period of extreme climate that dramatically reversed the course of global warming that brought the last Ice Age to a close. Understanding what mechanisms triggered and terminated this event remains enigmatic, but it is fundamental for gaining insights into the inner workings of Earth’s climate system. In this study, we used a combination of well-dated speleothem and ice-core records to pinpoint the timing of its onsets and terminations in various climatic regimes around the world. We show that the YD event occurred first at high northern latitudes and then propagated southward into the tropical monsoon belt through both atmospheric and oceanic processes, ultimately reaching Antarctica before reversing the course to its eventual termination.
Large variations of δ13C values in stalagmites from southeastern C hina during historical times: implications for anthropogenic deforestation
Publisher: Wiley
Date: 04-2015
DOI: 10.1111/BOR.12112
Multi-proxy validation of glacial-interglacial rainfall variations in southwest Sulawesi
Publisher: Springer Science and Business Media LLC
Date: 13-06-2023
DOI: 10.1038/S43247-023-00873-8
Abstract: Speleothem δ 18 O is widely used as a proxy for rainfall amount in the tropics on glacial-interglacial to interannual scales. However, uncertainties in the interpretation of this renowned proxy pose a vexing problem in tropical paleoclimatology. Here, we present paired multi-proxy geochemical measurements for stalagmites from southwest Sulawesi, Indonesia, and confirm changes in rainfall amount across ice age terminations. Collectively, the stalagmites span two glacial-interglacial transitions from ~380,000 to 330,000 and 230,000 to 170,000 years ago. Mg/Ca in the slow-growing stalagmites is affected by water moving through the karst and prior calcite precipitation, making it a good proxy for changes in local rainfall. When paired, Mg/Ca and δ 18 O corroborate prominent shifts from drier glacials to wetter interglacials in the core of the Australasian monsoon domain. These shifts in rainfall occur 4,000-7,000 years later than glacial-interglacial increases in global temperature and the associated response of Sulawesi vegetation, determined by speleothem δ 13 C.
Multiproxy evidence from caves of Native Americans altering the overlying landscape during the late Holocene of east-central North America
Publisher: SAGE Publications
Date: 27-11-2009
Abstract: We compare environmental changes recorded in stalagmites and alluvium from the mountainous Buckeye Creek basin of West Virginia, USA to a nearby, independent archaeological record of Native American presences in the forested watershed. A climatic record constructed from stable isotopic (δ 18 O calc and δ 13 C calc ) and trace metal (Sr/Ca) ratios in stalagmitic calcite is consistent with regional palynology during much of the Holocene. The stalagmite δ 13 C calc and Sr/Ca values track aridity associated with North Atlantic Ocean (NAO) ice-rafting events during solar minima. However, the δ 13 C calc record erges sharply from the Sr/Ca record at ~2100 (calendar) years BP, which maintains the same relationship with ice rafting in the NAO. A dramatic and sustained enrichment in δ 13 C calc values ( ‰) without a corresponding shift in Sr/Ca values, suggests a systemic change in above-cave vegetation and soil carbon. This hypothesis is corroborated by a record of the stable isotopic composition of bulk organic carbon (δ 13 C org ) in alluvial silts. Cultural artefacts record Native American presences in the watershed during the late Holocene and archaeologists place peak Native American presence as having occurred between 750 and 550 years BP, nearly contemporaneous with peaks in δ 13 C calc , δ 13 C org , and relative charcoal abundances documented herein. Notably, values of the three environmental proxies decrease after Native Americans abandoned the watershed. The available evidence is consistent with Native Americans having made significant changes to the area’s ecosystem and soils prior to the arrival of Euro-colonial peoples at ~225 years BP. Our findings highlight the active roles native peoples had in shaping the North American “wilderness” described prior to its destruction by early European settlers.
Spatio-temporal evolution of Australasian monsoon hydroclimate over the last 40,000 years
Publisher: Elsevier BV
Date: 05-2019
On the glacial-interglacial variability of the Asian monsoon in speleothem δ 18 O records
Publisher: American Association for the Advancement of Science (AAAS)
Date: 14-02-2020
Abstract: Moisture transport pathway effect offsets glacial forcings, likely explaining a lack of G-IG variability in Chinese cave records.
Timing and structure of Termination II in north China constrained by a precisely dated stalagmite record
Publisher: Elsevier BV
Date: 04-2019
A high-resolution stalagmite record of the Holocene East Asian monsoon from Mt Shennongjia, central China
Publisher: SAGE Publications
Date: 25-02-2010
Abstract: High-resolution oxygen isotope (δ 18 O) profiles of six stalagmites from Sanbao Cave in Hubei province, central China, established with 1413 oxygen isotope data and 65 230 Th ages, provide a continuous history of East Asian Summer Monsoon (EASM) intensity for the period from 13—0.2 thousand years before present (ky BP, relative to AD 1950). The δ 18 O record includes four distinct stages in the evolution of the EASM: (1) an abrupt transition (~11.5 ky BP) into the Holocene (2) a period of gradual increase in monsoon intensity (11.5—9.5 ky BP) (3) the maximum humid period (9.5—6.5 ky BP) and (4) a period of gradual decline in monsoon intensity (6.5—0.2 ky BP). Comparison of Sanbao with regional records of comparable resolution reveals that the timing of the beginning and end of the Holocene Optimum (as defined by the minimum in δ 18 O) was similar in the Indian and East Asian monsoon systems. This supports the idea that shifts in the monsoon tied to shifts in the mean position of the Inter-Tropical Convergence Zone (ITCZ) may control monsoon intensity throughout the entire low-latitude region of Asia on orbital timescales. This observation also supports the idea that the fluctuations in δ 18 O recorded across southern Asia reflect broad changes in the monsoon, as opposed to local meteoric precipitation. The EASM records from Sanbao largely follow orbital-scale insolation changes, yet exhibit similar variability to Greenland ice core δ 18 O on millennial to centennial scales during the early to middle Holocene ( r = 0.94).
A high-resolution record of atmospheric 14C based on Hulu Cave speleothem H82
Publisher: Elsevier BV
Date: 02-2012
The control of the tropical North Atlantic on Holocene millennial climate oscillations
Publisher: Geological Society of America
Date: 23-01-2017
DOI: 10.1130/G38573.1
Global Monsoon Dynamics and Climate Change
Publisher: Annual Reviews
Date: 30-05-2015
DOI: 10.1146/ANNUREV-EARTH-060313-054623
Abstract: This article provides a comprehensive review of the global monsoon that encompasses findings from studies of both modern monsoons and paleomonsoons. We introduce a definition for the global monsoon that incorporates its three-dimensional distribution and ultimate causes, emphasizing the direct drive of seasonal pressure system changes on monsoon circulation and depicting the intensity in terms of both circulation and precipitation. We explore the global monsoon climate changes across a wide range of timescales from tectonic to intraseasonal. Common features of the global monsoon are global homogeneity, regional ersity, seasonality, quasi-periodicity, irregularity, instability, and asynchroneity. We emphasize the importance of solar insolation, Earth orbital parameters, underlying surface properties, and land-air-sea interactions for global monsoon dynamics. We discuss the primary driving force of monsoon variability on each timescale and the relationships among dynamics on multiple timescales. Natural processes and anthropogenic impacts are of great significance to the understanding of future global monsoon behavior.
Stable isotope records of plant cover change and monsoon variation in the past 2200 years: evidence from laminated stalagmites in Beijing, China
Publisher: Wiley
Date: 06-2003
Hydroclimatic variations in southeastern China during the 4.2 ka event reflected by stalagmite records
Publisher: Copernicus GmbH
Date: 27-11-2018
Abstract: Abstract. Although the collapses of several Neolithic cultures in China are considered to have been associated with abrupt climate change during the 4.2 ka BP event (4.2–3.9 ka BP), the timing and nature of this event and the spatial distribution of precipitation between northern and southern China are still controversial. The hydroclimate of this event in southeastern China is still poorly known, except for a few published records from the lower reaches of the Yangtze River. In this study, a high-resolution record of monsoon precipitation between 5.3 and 3.57 ka BP based on a stalagmite from Shennong Cave, Jiangxi Province, southeast China, is presented. Coherent variations in δ18O and δ13C reveal that the climate in this part of China was dominantly wet between 5.3 and 4.5 ka BP and mostly dry between 4.5 and 3.57 ka BP, interrupted by a wet interval (4.2–3.9 ka BP). A comparison with other records from monsoonal China suggests that summer monsoon precipitation decreased in northern China but increased in southern China during the 4.2 ka BP event. We propose that the weakened East Asian summer monsoon controlled by the reduced Atlantic Meridional Overturning Circulation resulted in this contrasting distribution of monsoon precipitation between northern and southern China. During the 4.2 ka BP event the rain belt remained longer at its southern position, giving rise to a pronounced humidity gradient between northern and southern China.
Indian summer monsoon variability in northeastern India during the last two millennia
Publisher: Elsevier BV
Date: 2021
Earliest parietal art: hominin hand and foot traces from the middle Pleistocene of Tibet
Publisher: Elsevier BV
Date: 12-2021
Measurement of Attogram Quantities of 231Pa in Dissolved and Particulate Fractions of Seawater by Isotope Dilution Thermal Ionization Mass Spectroscopy
Publisher: American Chemical Society (ACS)
Date: 28-01-2003
DOI: 10.1021/AC026247R
Abstract: A technique has been developed to quantify ultratrace 231Pa (50-2000 ag 1 ag = 10(-18) g) concentrations in seawater using isotope-dilution thermal ionization mass spectrometry (TIMS). The method is a modification of a process developed by Pickett et al. (Pickett, D. A. Murrell, M. T. Williams, R. W. Anal. Chem. 1994, 66, 1044-1049) and extends the technique to very low levels of protactinium. The procedural blank is 16 +/- 15 ag (2sigma), and the ionization efficiency (ions generated/atom loaded) approaches 0.5%. Measurement time is <1 h. The amount of 231Pa needed to produce 231Pa data with an uncertainty of +/-4-12% is 100-1000 ag (approximately 3 x 10(5) to 3 x 10(6) atoms). Replicate measurements made on known standards and seawater s les demonstrate that the analytical precision approximates that expected from counting statistics and that, based on detection limits of 38 and 49 ag, protactinium can be detected in a minimum s le size of surface seawater of approximately 2 L for suspended particulate matter and <0.1 L for filtered (<0.4 microm) seawater, respectively. The concentration of 231Pa (tens of attograms per liter) can be determined with an uncertainty of +/-5-10% (2sigma) for suspended particulate matter filtered from 5 to 10 L of seawater. For the dissolved fraction, 0.5-1 L of seawater yields 231Pa measurements with a precision of 1-10%. S le size requirements are orders of magnitude less than traditional decay-counting techniques and significantly less than previously reported ICP-MS techniques. Our technique can also be applied to other environmental s les, including cave waters, rivers, and igneous rocks.
A Test of Climate, Sun, and Culture Relationships from an 1810-Year Chinese Cave Record
Publisher: American Association for the Advancement of Science (AAAS)
Date: 07-11-2008
Abstract: A record from Wanxiang Cave, China, characterizes Asian Monsoon (AM) history over the past 1810 years. The summer monsoon correlates with solar variability, Northern Hemisphere and Chinese temperature, Alpine glacial retreat, and Chinese cultural changes. It was generally strong during Europe's Medieval Warm Period and weak during Europe's Little Ice Age, as well as during the final decades of the Tang, Yuan, and Ming Dynasties, all times that were characterized by popular unrest. It was strong during the first several decades of the Northern Song Dynasty, a period of increased rice cultivation and dramatic population increase. The sign of the correlation between the AM and temperature switches around 1960, suggesting that anthropogenic forcing superseded natural forcing as the major driver of AM changes in the late 20th century.
The global monsoon across time scales: Mechanisms and outstanding issues
Publisher: Elsevier BV
Date: 11-2017
A review of the South American monsoon history as recorded in stable isotopic proxies over the past two millennia
Publisher: Copernicus GmbH
Date: 23-08-2012
Abstract: Abstract. We review the history of the South American summer monsoon (SASM) over the past ~2000 yr based on high-resolution stable isotope proxies from speleothems, ice cores and lake sediments. Our review is complemented by an analysis of an isotope-enabled atmospheric general circulation model (GCM) for the past 130 yr. Proxy records from the monsoon belt in the tropical Andes and SE Brazil show a very coherent behavior over the past 2 millennia with significant decadal to multidecadal variability superimposed on large excursions during three key periods: the Medieval Climate Anomaly (MCA), the Little Ice Age (LIA) and the current warm period (CWP). We interpret these three periods as times when the SASM's mean state was significantly weakened (MCA and CWP) and strengthened (LIA), respectively. During the LIA each of the proxy archives considered contains the most negative δ18O values recorded during the entire record length. On the other hand, the monsoon strength is currently rather weak in a 2000-yr historical perspective, rivaled only by the low intensity during the MCA. Our climatic interpretation of these archives is consistent with our isotope-based GCM analysis, which suggests that these sites are sensitive recorders of large-scale monsoon variations. We hypothesize that these centennial-scale climate anomalies were at least partially driven by temperature changes in the Northern Hemisphere and in particular over the North Atlantic, leading to a latitudinal displacement of the ITCZ and a change in monsoon intensity (amount of rainfall upstream over the Amazon Basin). This interpretation is supported by several independent records from different proxy archives and modeling studies. Although ENSO is the main forcing for δ18O variability over tropical South America on interannual time scales, our results suggest that its influence may be significantly modulated by North Atlantic climate variability on longer time scales. Finally, our analyses indicate that isotopic proxies, because of their ability to integrate climatic information on large spatial scales, could complement more traditional proxies such as tree rings or documentary evidence. Future climate reconstruction efforts could potentially benefit from including isotopic proxies as large-scale predictors in order to better constrain past changes in the atmospheric circulation.
Stratigraphy and geochronology of pitfall accumulations in caves and fissures, Bermuda
Publisher: Elsevier BV
Date: 05-2004
Vegetation and environmental changes in tropical South America from the last glacial to the Holocene documented by multiple cave sediment proxies
Publisher: Elsevier BV
Date: 10-2019
Climate significance of speleothem δ18O from central China on decadal timescale
Publisher: Elsevier BV
Date: 07-2015
Holocene relative sea-level changes and coastal evolution along the coastlines of Kamaran Island and As-Salif Peninsula, Yemen, southern Red Sea
Publisher: Elsevier BV
Date: 2021
Variability of PDO identified by a last 300-year stalagmite δ18O record in Southwest China
Publisher: Elsevier BV
Date: 06-2021
Indian summer monsoon variability during the last millennium as recorded in stalagmite from Baratang Mahadev cave, Andaman Islands
Publisher: Elsevier BV
Date: 11-2020
Human remains from Zhirendong, South China, and modern human emergence in East Asia
Publisher: Proceedings of the National Academy of Sciences
Date: 25-10-2010
Abstract: The 2007 discovery of fragmentary human remains (two molars and an anterior mandible) at Zhirendong (Zhiren Cave) in South China provides insight in the processes involved in the establishment of modern humans in eastern Eurasia. The human remains are securely dated by U-series on overlying flowstones and a rich associated faunal s le to the initial Late Pleistocene, kya. As such, they are the oldest modern human fossils in East Asia and predate by ,000 y the oldest previously known modern human remains in the region. The Zhiren 3 mandible in particular presents derived modern human anterior symphyseal morphology, with a projecting tuber symphyseos, distinct mental fossae, modest lateral tubercles, and a vertical symphysis it is separate from any known late archaic human mandible. However, it also exhibits a lingual symphyseal morphology and corpus robustness that place it close to later Pleistocene archaic humans. The age and morphology of the Zhiren Cave human remains support a modern human emergence scenario for East Asia involving dispersal with assimilation or populational continuity with gene flow. It also places the Late Pleistocene Asian emergence of modern humans in a pre-Upper Paleolithic context and raises issues concerning the long-term Late Pleistocene coexistence of late archaic and early modern humans across Eurasia.
U-Th dating of lake sediments: Lessons from the 700 ka sediment record of Lake Junín, Peru
Publisher: Elsevier BV
Date: 09-2020
Hydro-climatic variability in the southwestern Indian Ocean between 6000 and 3000 years ago
Publisher: Copernicus GmbH
Date: 07-12-2018
Abstract: Abstract. The “4.2 ka event” is frequently described as a major global climate anomaly between 4.2 and 3.9 ka, which defines the beginning of the current Meghalayan age in the Holocene epoch. The “event” has been disproportionately reported from proxy records from the Northern Hemisphere, but its climatic manifestation remains much less clear in the Southern Hemisphere. Here, we present highly resolved and chronologically well-constrained speleothem oxygen and carbon isotopes records between ∼6 and 3 ka from Rodrigues Island in the southwestern subtropical Indian Ocean, located ∼600 km east of Mauritius. Our records show that the 4.2 ka event did not manifest itself as a period of major climate change at Rodrigues Island in the context of our record's length. Instead, we find evidence for a multi-centennial drought that occurred near-continuously between 3.9 and 3.5 ka and temporally coincided with climate change throughout the Southern Hemisphere.
Speleothem record from Pentadactylos cave (Cyprus): new insights into climatic variations during MIS 6 and MIS 5 in the Eastern Mediterranean
Publisher: Elsevier BV
Date: 12-2020
Modulation of centennial-scale hydroclimate variations in the middle Yangtze River Valley by the East Asian-Pacific pattern and ENSO over the past two millennia
Publisher: Elsevier BV
Date: 12-2021
Great flood in the middle-lower Yellow River reaches at 4000 a BP inferred from accurately-dated stalagmite records
Publisher: Elsevier BV
Date: 02-2018
Multi-speleothem record reveals tightly coupled climate between central Europe and Greenland during Marine Isotope Stage 3
Publisher: Geological Society of America
Date: 12-2014
DOI: 10.1130/G36063.1
Source parameters of the great Sumatran megathrust earthquakes of 1797 and 1833 inferred from coral microatolls
Publisher: American Geophysical Union (AGU)
Date: 06-2006
DOI: 10.1029/2005JB004025
Geomorphology and genesis of the remarkable Araras Ridge tufa deposit, Western Brazil
Publisher: Elsevier BV
Date: 11-2011
Can vein-filling speleothems constrain the timing of deep-seated gravitational slope deformation? A case study from the Vinschgau (Italian Alps)
Publisher: Springer Science and Business Media LLC
Date: 05-07-2018
IntCal13 and Marine13 radiocarbon age calibration curves 0-50,000 years cal BP
Publisher: Cambridge University Press (CUP)
Date: 2013
DOI: 10.2458/AZU_JS_RC.55.16947
Abstract: The IntCal09 and Marine09 radiocarbon calibration curves have been revised utilizing newly available and updated data sets from 14 C measurements on tree rings, plant macrofossils, speleothems, corals, and foraminifera. The calibration curves were derived from the data using the random walk model (RWM) used to generate IntCal09 and Marine09, which has been revised to account for additional uncertainties and error structures. The new curves were ratified at the 21st International Radiocarbon conference in July 2012 and are available as Supplemental Material at www.radiocarbon.org. The database can be accessed at intcal.qub.ac.uk/intcal13/.
Geochronology of late Pleistocene to Holocene speleothemsfrom central Texas: Implications for regional paleoclimate
Publisher: Geological Society of America
Date: 12-2001
Early Holocene permafrost retreat in West Siberia amplified by reorganization of westerly wind systems
Publisher: Springer Science and Business Media LLC
Date: 04-06-2026
DOI: 10.1038/S43247-021-00238-Z
Abstract: Rapid permafrost degradation and peatland expansion occurred in Eurasia during the Early Holocene and may be analogous to the region’s response to anthropogenic warming. Here we present a 230 Th-dated, multiproxy speleothem record with subdecadal s ling resolution from Kyok-Tash Cave, at the modern permafrost margin in the northern Altai Mountains, southwestern Siberia. Stalagmite K4, covering the period 11,400 to 8,900 years before present, indicates an absence of stable permafrost within three centuries of the Younger Dryas termination. Between 11,400 and 10,400 years ago, speleothem δ 18 O is antiphased between the Altai and Ural ranges, suggesting a reorganization of the westerly wind systems that led to warmer and wetter winters over West Siberia and Altai, relative to the zonally adjacent regions of Northern Eurasia. At the same time, there is evidence of peak permafrost degradation and peatland expansion in West Siberia, consistent with the interpreted climate anomaly. Based on these findings, we suggest that modern permafrost in Eurasia is sensitive to feedbacks in the ocean-cryosphere system, which are projected to alter circulation regimes over the continent.
Persistent multidecadal power of the Indian Summer Monsoon
Publisher: Elsevier BV
Date: 02-2010
Radiocarbon Dating of Deep-Sea Corals
Publisher: Cambridge University Press (CUP)
Date: 2002
DOI: 10.1017/S0033822200031921
Abstract: Deep-sea corals are a promising new archive of paleoclimate. Coupled radiocarbon and U-series dates allow 14 C to be used as a tracer of ocean circulation rate in the same manner as it is used in the modern ocean. Diagenetic alteration of coral skeletons on the seafloor requires a thorough cleaning of contaminating phases of carbon. In addition, 10% of the coral must be chemically leached prior to dissolution to remove adsorbed modern CO 2 . A survey of modern s les from the full δ 14 C gradient in the deep ocean demonstrates that the coralline CaCO 3 records the radiocarbon value of the dissolved inorganic carbon.
Quaternary glaciation and hydrologic variation in the South American tropics as reconstructed from the Lake Titicaca drilling project
Publisher: Cambridge University Press (CUP)
Date: 11-2007
DOI: 10.1016/J.YQRES.2007.07.008
Abstract: A 136-m-long drill core of sediments was recovered from tropical high-altitude Lake Titicaca, Bolivia-Peru, enabling a reconstruction of past climate that spans four cycles of regional glacial advance and retreat and that is estimated to extend continuously over the last 370,000 yr. Within the errors of the age model, the periods of regional glacial advance and retreat are concordant respectively with global glacial and interglacial stages. Periods of ice advance in the southern tropical Andes generally were periods of positive water balance, as evidenced by deeper and fresher conditions in Lake Titicaca. Conversely, reduced glaciation occurred during periods of negative water balance and shallow closed-basin conditions in the lake. The apparent coincidence of positive water balance of Lake Titicaca and glacial growth in the adjacent Andes with Northern Hemisphere ice sheet expansion implies that regional water balance and glacial mass balance are strongly influenced by global-scale temperature changes, as well as by precessional forcing of the South American summer monsoon.
The African Humid Period, rapid climate change events, the timing of human colonization, and megafaunal extinctions in Madagascar during the Holocene: Evidence from a 2m Anjohibe Cave stalagmite
Publisher: Elsevier BV
Date: 04-2019
Last glacial and Holocene stable isotope record of fossil dripwater from subtropical Brazil based on analysis of fluid inclusions in stalagmites
Publisher: Elsevier BV
Date: 09-2017
Flux of Particulate Elements in the North Atlantic Ocean Constrained by Multiple Radionuclides
Publisher: American Geophysical Union (AGU)
Date: 12-2018
DOI: 10.1029/2018GB005994
Climate changes in Northeastern Brazil from deglacial to Meghalayan periods and related environmental impacts
Publisher: Elsevier BV
Date: 12-2020
The WAIS Divide deep ice core WD2014 chronology – Part 1: Methane synchronization (68–31 ka BP) and the gas age–ice age difference
Publisher: Copernicus GmbH
Date: 05-02-2015
Abstract: Abstract. The West Antarctic Ice Sheet Divide (WAIS Divide, WD) ice core is a newly drilled, high-accumulation deep ice core that provides Antarctic climate records of the past ∼68 ka at unprecedented temporal resolution. The upper 2850 m (back to 31.2 ka BP) have been dated using annual-layer counting. Here we present a chronology for the deep part of the core (67.8–31.2 ka BP), which is based on stratigraphic matching to annual-layer-counted Greenland ice cores using globally well-mixed atmospheric methane. We calculate the WD gas age–ice age difference (Δage) using a combination of firn densification modeling, ice-flow modeling, and a data set of δ15N-N2, a proxy for past firn column thickness. The largest Δage at WD occurs during the Last Glacial Maximum, and is 525 ± 120 years. Internally consistent solutions can be found only when assuming little to no influence of impurity content on densification rates, contrary to a recently proposed hypothesis. We synchronize the WD chronology to a linearly scaled version of the layer-counted Greenland Ice Core Chronology (GICC05), which brings the age of Dansgaard–Oeschger (DO) events into agreement with the U/Th absolutely dated Hulu Cave speleothem record. The small Δage at WD provides valuable opportunities to investigate the timing of atmospheric greenhouse gas variations relative to Antarctic climate, as well as the interhemispheric phasing of the "bipolar seesaw".
Speleothem climate records from deep time? Exploring the potential with an example from the Permian
Publisher: Geological Society of America
Date: 05-2010
DOI: 10.1130/G30354.1
Asian summer monsoon precipitation recorded by stalagmite oxygen isotopic composition in the western Loess Plateau during AD1875–2003 and its linkage with ocean-atmosphere system
Publisher: Elsevier BV
Date: 07-2008
Enhanced El Niño–Southern Oscillation Variability in Recent Decades
Publisher: American Geophysical Union (AGU)
Date: 04-04-2020
DOI: 10.1029/2019GL083906
Onset of deglacial warming in West Antarctica driven by local orbital forcing
Publisher: Springer Science and Business Media LLC
Date: 08-2013
DOI: 10.1038/NATURE12376
Abstract: The cause of warming in the Southern Hemisphere during the most recent deglaciation remains a matter of debate. Hypotheses for a Northern Hemisphere trigger, through oceanic redistributions of heat, are based in part on the abrupt onset of warming seen in East Antarctic ice cores and dated to 18,000 years ago, which is several thousand years after high-latitude Northern Hemisphere summer insolation intensity began increasing from its minimum, approximately 24,000 years ago. An alternative explanation is that local solar insolation changes cause the Southern Hemisphere to warm independently. Here we present results from a new, annually resolved ice-core record from West Antarctica that reconciles these two views. The records show that 18,000 years ago snow accumulation in West Antarctica began increasing, coincident with increasing carbon dioxide concentrations, warming in East Antarctica and cooling in the Northern Hemisphere associated with an abrupt decrease in Atlantic meridional overturning circulation. However, significant warming in West Antarctica began at least 2,000 years earlier. Circum-Antarctic sea-ice decline, driven by increasing local insolation, is the likely cause of this warming. The marine-influenced West Antarctic records suggest a more active role for the Southern Ocean in the onset of deglaciation than is inferred from ice cores in the East Antarctic interior, which are largely isolated from sea-ice changes.
Speleothem‐Based Hydroclimate Reconstructions During the Penultimate Deglaciation in Northern China
Publisher: American Geophysical Union (AGU)
Date: 04-2021
DOI: 10.1029/2020PA004072
Abstract: Trace elements in a speleothem have been considered to be effective proxies to characterize hydroclimatic changes. In this study, we present speleothem trace element records of the penultimate glacial‐interglacial transition from 138 to 125.8 ka BP from the Shangxiaofeng cave in northeastern China. We used two analytical methods, namely, inductively coupled plasma optical emission spectrometry (ICP‐OES) and the Avaatech high‐resolution X‐ray fluorescence (XRF) core scanner. Both methods showed good consistency for Sr/Ca but not for Mg/Ca because of the high Mg detection limit of XRF. By comparing the trace element ratios (Sr/Ca and Mg/Ca) with δ 13 C and by analyzing the slope of the regression line of ln(Sr/Ca) versus ln(Mg/Ca), we found that trace element variations were dominated by hydroclimate‐related prior calcite precipitation (PCP) and water‐rock interaction (WRI). A gradually decreasing trend of Sr/Ca, Mg/Ca, and δ 13 C records during the glacial‐interglacial transition indicated that the hydroclimate moved toward a moist condition with an intensified East Asian summer monsoon (EASM) and transgression of the coastline. The transgression shortened the distance between the cave site and the coastline, possibly contributing to persistent rainfall enhancement at the study site.
Putting the Younger Dryas cold event into context
Publisher: Elsevier BV
Date: 05-2010
Black carbon traces of human activities in stalagmites from Turkey
Publisher: Elsevier BV
Date: 11-2020
The timing, two-pulsed nature, and variable climatic expression of the 4.2 ka event: A review and new high-resolution stalagmite data from Namibia
Publisher: Elsevier BV
Date: 04-2018
Precise dating of East-Asian-Monsoon D/O events during 95–56 ka BP: Based on stalagmite data from Shanbao Cave at Shennongjia, China
Publisher: Springer Science and Business Media LLC
Date: 02-2007
1000-Year Quasi-Periodicity of Weak Monsoon Events in Temperate Northeast Asia since the Mid-Holocene
Publisher: Springer Science and Business Media LLC
Date: 09-11-2017
DOI: 10.1038/S41598-017-15566-4
Abstract: The Holocene variability in the East Asian summer monsoon (EASM) based on speleothem δ 18 O records has inconsistencies in timing, duration, and expression of millennial-scale events among nearby regions, and even within the same cave. Here, we present another stalagmite δ 18 O record with multi-decadal time resolution from the temperate Korean Peninsula (KP) for the last 5500 years in order to compare with Holocene millennial-scale EASM events from Southeast Asia. Based on our new stalagmite δ 18 O record, millennial-scale events since the mid-Holocene were successfully identified in the KP, representing a noticeable cyclic pattern with a periodicity of around 1000 years. We propose that the Holocene millennial-scale events are common hydroclimatic phenomena at least in the East Asian monsoon system. Meanwhile, the shorter periodicity of millennial-scale events than that of the North Atlantic region is likely to decouple the EASM system from the North Atlantic climate system. This observation suggests that weak EASM and North Atlantic Bond events may have been induced independently by direct solar activity (and then possible feedback) and ocean–ice sheet dynamics, respectively, rather than simple propagation from the North Atlantic to the EASM regions.
Coupling of the Asian monsoon and Antarctic climates on multiple timescales and implications for termination
Publisher: Research Square Platform LLC
Date: 11-04-2022
DOI: 10.21203/RS.3.RS-1492594/V1
Abstract: Recurrent and intense climate changes during glacial periods are registered in geological records globally. A strong bipolar coupling has been revealed on the millennial timescale, while the north-south counterparts on finer timescales is less clear due to the locality of the Greenland ice core. Our high-resolution stalagmite record, which represents the East Asian summer monsoon circulation intensity, resembles the Antarctic temperature on millennial to sub-centennial timescales during the last glacial. This possibly indicates a teleconnection between monsoon and Antarctica via the Southern Ocean or the Intertropical Convergence Zone. Furthermore, monsoonal event sequence from Heinrich 4 to Dansgaard-Oeschger 8 cycle is highly analogous to that during Termination 1 and the Marine Isotope Stage 4/3 transition at trend, litude and internal structures. Within the context of correlative records, we suggest that the maximum ice volume and the positive feedbacks related with CO 2 buildup are critical for the terminations, rather than millennial-scale events.
87Sr/86Sr and Sr/Ca in speleothems for paleoclimate reconstruction in Central China between 70 and 280 kyr ago
Publisher: Elsevier BV
Date: 08-2005
Heterogenous Late Holocene Climate in the Eastern Mediterranean—The Kocain Cave Record From SW Turkey
Publisher: American Geophysical Union (AGU)
Date: 18-10-2021
DOI: 10.1029/2021GL094733
Abstract: Palaeoclimate variability must be constrained to predict the nature and impacts of future climate change in the Eastern Mediterranean. Here, we present a late Holocene high‐resolution multiproxy data set from Kocain Cave, the first of its kind from SW Turkey. Regional fluctuations in effective‐moisture are recorded by variations in magnesium, strontium, phosphorous and carbon isotopes, with oxygen isotopes reacting to changes in precipitation and effective‐moisture. The new record shows a double‐peak of arid conditions at 1150 and 800 BCE, a wet period 330–460 CE followed by a rapid shift to dry conditions 460–830 CE, and a dry/wet Medieval Climate Anomaly/Little Ice Age pattern. Large discrepancies exist between Turkish records and the Kocain record, which shares more similarities with other Eastern Mediterranean coastal records. Heterogeneity of regional climate and palaeoclimate proxy records are emphasized.
Timing and climatic impact of Greenland interstadials recorded in stalagmites from northern Turkey
Publisher: American Geophysical Union (AGU)
Date: 10-2009
DOI: 10.1029/2009GL040050
Ion microprobe δ18O analyses to calibrate slow growth rate speleothem records with regional δ18O records of precipitation
Publisher: Elsevier BV
Date: 2018
U/Th dating of cold-seep carbonates: An initial comparison
Publisher: Elsevier BV
Date: 11-2010
Speleothems as sensitive recorders of volcanic eruptions – the Bronze Age Minoan eruption recorded in a stalagmite from Turkey
Publisher: Elsevier BV
Date: 04-2014
The GEOTRACES Intermediate Data Product 2014
Publisher: Elsevier BV
Date: 12-2015
East Asian monsoon variability since the Mid-Holocene recorded in a high-resolution, absolute-dated aragonite speleothem from eastern China
Publisher: Elsevier BV
Date: 11-2008
Holocene variability in the intensity of wind-gap upwelling in the tropical eastern Pacific
Publisher: American Geophysical Union (AGU)
Date: 08-2015
DOI: 10.1002/2015PA002794
The palaeoenvironmental significance of δ13C of stalagmite BW ‐1 from Beijing, C hina during Y ounger D ryas intervals inferred from the g
Publisher: Wiley
Date: 19-07-2013
DOI: 10.1111/BOR.12034
The variation of summer monsoon precipitation in central China since the last deglaciation
Publisher: Elsevier BV
Date: 03-2010
A detailed East Asian monsoon history surrounding the ‘Mystery Interval’ derived from three Chinese speleothem records
Publisher: Cambridge University Press (CUP)
Date: 07-2014
DOI: 10.1016/J.YQRES.2014.01.010
Abstract: The ‘Mystery Interval’ (MI, 17.5−14.5 ka) was the first stage of the last deglaciation, a key interval for understanding mechanisms of glacial–interglacial cycles. To elucidate possible causes of the MI, here we present three high-resolution, precisely dated oxygen-isotope records of stalagmites from Qingtian and Hulu Caves in China, reflecting changes in the East Asian summer monsoon (EASM) then. Based on well-established chronologies using precise 230 Th dates and annual-band counting results, the two-cave δ 18 O profiles of ~7-yr resolution match well at decadal timescales. Both of the two-cave records document an abrupt weakening (2‰ of δ 18 O rise within 20 yr) in the EASM at ~16.1 ka, coinciding with the transition of the two-phased MI reconstructed from New Mexico's Lake Estancia. Our results indicate that the maximum southward displacement of the Intertropical Convergence Zone and associated southward shift of polar jet stream may generate this two-phase feature of the MI during that time. We also discover a linear relationship among decreasing EASM intensity, rising atmospheric CO 2 and weakening Atlantic Meridional Overturning Circulation between the MI and Younger Dryas episodes, suggesting a strong coupling of atmospheric/oceanic circulations in response to the millennial-scale forcing, which in turn regulates global climate changes and carbon cycles.
Evidence from giant-clam <i>δ</i><sup>18</sup>O of intense El Ninõ–Southern Oscillation-related variability but reduced frequency 3700 years ago
Publisher: Copernicus GmbH
Date: 04-2020
Abstract: Abstract. Giant clams (Tridacna) are the largest marine bivalves, and their carbonate shells can be used for high-resolution paleoclimate reconstructions. In this contribution, δ18Oshell was used to estimate climatic variation in the Xisha Islands of the South China Sea. We first evaluate sea surface temperature (SST) and sea surface salinity (SSS) influence on the modern res led monthly (r-monthly) resolution of Tridacna gigas δ18Oshell. The results obtained reveal that δ18Oshell seasonal variation is mainly controlled by SST and appears to be insensitive to local SSS change. Thus, the δ18O of Tridacna shells can be roughly used as a proxy of local SST: a 1 ‰ δ18Oshell change is roughly equal to 4.41 ∘C of SST. The r-monthly δ18O of a 40-year-old Tridacna squamosa (3673±28 BP) from the North Reef of the Xisha Islands was analyzed and compared with the modern specimen. The difference between the average δ18O of the fossil Tridacna shell (δ18O =-1.34 ‰) and the modern Tridacna specimen (δ18O =-1.15 ‰) probably implies a warm climate, roughly 0.84 ∘C, 3700 years ago. The seasonal variation 3700 years ago was slightly lower than that suggested by modern instrumental data, and the transition between warm and cold seasons was rapid. Higher litudes of reconstructed r-monthly and r-annual SST anomalies imply an enhanced climate variability during this warm period. Investigation of the El Ninõ–Southern Oscillation (ENSO) variation (based on the reconstructed SST series) indicates reduced ENSO frequency but increased ENSO-related variability and extreme El Ninõ winter events 3700 years ago.
Abrupt climate change: De-bate or action
Publisher: Science China Press., Co. Ltd.
Date: 2004
DOI: 10.1360/04WD0223
Integrating U-Th, 14C, and 210Pb methods to produce a chronologically reliable isotope record for the Belize River Valley Maya from a low-uranium stalagmite
Publisher: SAGE Publications
Date: 04-2019
Abstract: Social and environmental changes had great spatiotemporal variability in the Maya Lowlands during the Classic and Postclassic Periods, and stalagmites promise high-resolution paleoclimate data that can refine our understanding of this complex time. Unfortunately, stalagmites in this region are often difficult to date by U-Th methods because of low initial uranium concentrations. Other dating techniques can be used on such stalagmites, and we present here an age–depth model for BZBT1, a low-uranium stalagmite s led from Box Tunich cave in the Belize River Valley. This age–depth model dates the growth of BZBT1 to between 400 and 1610 yr BP (340–1550 CE) by combining evidence from U-Th results, radiocarbon dating of both stalagmite CaCO 3 and trapped organic material, and 210 Pb dating. The resulting stable isotope record from BZBT1 reveals paleoclimate changes that affected local Maya populations during the Classic and early Postclassic Periods. This record is further refined by isotopically tuning the BZBT1 data with two other regional stalagmite records. Our work offers additional paleoclimate insight into the relationship between the Maya and their environment from a stalagmite that would typically be disregarded for research purposes. Continued research into alternative dating techniques for speleothems can enable additional scientific discovery while promoting speleothem conservation.
A Chinese cave links climate change, social impacts and human adaptation over the last 500 years
Publisher: Springer Science and Business Media LLC
Date: 13-08-2015
DOI: 10.1038/SREP12284
Abstract: The collapse of some pre-historical and historical cultures, including Chinese dynasties were presumably linked to widespread droughts, on the basis of synchronicities of societal crises and proxy-based climate events. Here, we present a comparison of ancient inscriptions in Dayu Cave from Qinling Mountains, central China, which described accurate times and detailed impacts of seven drought events during the period of 1520–1920 CE, with high-resolution speleothem records from the same cave. The comparable results provide unique and robust tests on relationships among speleothem δ 18 O changes, drought events and societal unrest. With direct historical evidences, our results suggest that droughts and even modest events interrupting otherwise wet intervals can cause serious social crises. Modeling results of speleothem δ 18 O series suggest that future precipitation in central China may be below the average of the past 500 years. As Qinling Mountain is the main recharge area of two large water transfer projects and habitats of many endangered species, it is imperative to explore an adaptive strategy for the decline in precipitation and/or drought events.
Potential influence of temperature changes in the Southern Hemisphere on the evolution of the Asian summer monsoon during the last glacial period
Publisher: Elsevier BV
Date: 2016
The IntCal20 Northern Hemisphere Radiocarbon Age Calibration Curve (0–55 cal kBP)
Publisher: Cambridge University Press (CUP)
Date: 08-2020
DOI: 10.1017/RDC.2020.41
Abstract: Radiocarbon ( 14 C) ages cannot provide absolutely dated chronologies for archaeological or paleoenvironmental studies directly but must be converted to calendar age equivalents using a calibration curve compensating for fluctuations in atmospheric 14 C concentration. Although calibration curves are constructed from independently dated archives, they invariably require revision as new data become available and our understanding of the Earth system improves. In this volume the international 14 C calibration curves for both the Northern and Southern Hemispheres, as well as for the ocean surface layer, have been updated to include a wealth of new data and extended to 55,000 cal BP. Based on tree rings, IntCal20 now extends as a fully atmospheric record to ca. 13,900 cal BP. For the older part of the timescale, IntCal20 comprises statistically integrated evidence from floating tree-ring chronologies, lacustrine and marine sediments, speleothems, and corals. We utilized improved evaluation of the timescales and location variable 14 C offsets from the atmosphere (reservoir age, dead carbon fraction) for each dataset. New statistical methods have refined the structure of the calibration curves while maintaining a robust treatment of uncertainties in the 14 C ages, the calendar ages and other corrections. The inclusion of modeled marine reservoir ages derived from a three-dimensional ocean circulation model has allowed us to apply more appropriate reservoir corrections to the marine 14 C data rather than the previous use of constant regional offsets from the atmosphere. Here we provide an overview of the new and revised datasets and the associated methods used for the construction of the IntCal20 curve and explore potential regional offsets for tree-ring data. We discuss the main differences with respect to the previous calibration curve, IntCal13, and some of the implications for archaeology and geosciences ranging from the recent past to the time of the extinction of the Neanderthals.
Sub-millennial variability of Asian monsoon intensity during the early MIS 3 and its analogue to the ice age terminations
Publisher: Elsevier BV
Date: 05-2010
Evolution of marine terraces and sea level in the last interglacial, Cave Hill, Barbados
Publisher: Geological Society of America
Date: 2004
DOI: 10.1130/B25167.1
Variation of initial 230Th/232Th and limits of high precision U–Th dating of shallow-water corals
Publisher: Elsevier BV
Date: 09-2008
A novel application of triple oxygen isotope ratios of speleothems
Publisher: Elsevier BV
Date: 02-2020
Timing and structure of the 8.2 kyr B.P. event inferred from δ18O records of stalagmites from China, Oman, and Brazil
Publisher: Geological Society of America
Date: 11-2009
DOI: 10.1130/G30126A.1
Protracted Indian monsoon droughts of the past millennium and their societal impacts
Publisher: Proceedings of the National Academy of Sciences
Date: 19-09-2022
Abstract: Protracted droughts lasting years to decades constitute severe threats to human welfare across the Indian subcontinent. Such events are, however, rare during the instrumental period ( ca . since 1871 CE). In contrast, the historic documentary evidence indicates the repeated occurrences of protracted droughts in the region during the preinstrumental period implying that either the instrumental observations underestimate the full spectrum of monsoon variability or the historic accounts overestimate the severity and duration of the past droughts. Here we present a temporally precise speleothem-based oxygen isotope reconstruction of the Indian summer monsoon precipitation variability from Mawmluh cave located in northeast India. Our data reveal that protracted droughts, embedded within multidecadal intervals of reduced monsoon rainfall, frequently occurred over the past millennium. These extreme events are in striking temporal synchrony with the historically documented droughts, famines, mass mortality events, and geopolitical changes in the Indian subcontinent. Our findings necessitate reconsideration of the region’s current water resources, sustainability, and mitigation policies that discount the possibility of protracted droughts in the future.
Highly Variable El Niño–Southern Oscillation Throughout the Holocene
Publisher: American Association for the Advancement of Science (AAAS)
Date: 04-01-2013
Abstract: The El Niño–Southern Oscillation (ENSO) is the most energetic, quasiperiodic climate oscillation in the world—every few years warming large expanses of the surface equatorial Pacific Ocean surface and impacting temperatures and rainfall patterns across the globe. A pressing question, in the context of global warming, is whether ENSO might be affected by the rising atmospheric temperatures caused by anthropogenic greenhouse gas emissions. Climate models do not agree on the answer to this question, but one place to look for data about how global temperatures might influence ENSO is the record of past ENSO variability. Cobb et al. (p. 67 ) present a record of ENSO variability spanning the past 7000 years, in an attempt better to define its response to insolation forcing over this same period. The findings reveal high variability in ENSO behavior that has no clear dependence on insolation, which implies that a link to warming, if it exists, may be difficult to detect.
Determination of aragonite trace element distribution coefficients from speleothem calcite–aragonite transitions
Publisher: Elsevier BV
Date: 10-2016
East central North America climates during marine isotope stages 3-5
Publisher: American Geophysical Union (AGU)
Date: 05-2014
DOI: 10.1002/2014GL059884
Karst hydrological changes during the Late-Holocene in Southwestern China
Publisher: Elsevier BV
Date: 04-2021
A Great Basin-wide dry episode during the first half of the Mystery Interval?
Publisher: Elsevier BV
Date: 12-2009
Late Pleistocene–Holocene climatic implications of high‐resolution stable isotope profiles of a speleothem from south‐central Anatolia, Turkey
Publisher: Wiley
Date: 02-12-2021
DOI: 10.1002/JQS.3401
Abstract: High‐resolution 230 Th ages and stable isotope (δ 18 O and δ 13 C) records from a stalagmite that grew between 39 and 2 ka in Incesu Cave located in south‐central Anatolia allow us to evaluate paleoclimate conditions for growth periods during Marine Isotope Stage 3 (MIS3) and the Holocene. High δ 18 O values and Heinrich events H3 and H4 are observed during the MIS3 interval. After a dry period in the Younger Dryas, low values between ca. 10 and 5.3 ka suggest a transition to wet mid‐ to early Holocene conditions. In the early Holocene, there are drier periods at 9.4 and 10.3 ka, coincident with cooling events recorded in the North Atlantic sediments and, after 5.3 ka a relatively dry late Holocene is seen. The IN‐01 isotope record is in phase with general trends of speleothem records in Turkey and the Eastern Mediterranean but differs in detail at the millennial scale. The more depleted δ 18 O values of IN‐01 compared to those of Eastern Mediterranean speleothems during the Holocene indicate that central Anatolian winter rainfall was isotopically influenced by the same air mass trajectories derived from the North Atlantic and Mediterranean with an isotopic rain shadow effect.
Is Chinese stalagmite δ18O solely controlled by the Indian summer monsoon?
Publisher: Springer Science and Business Media LLC
Date: 12-02-2019
Reconstruction of the Northeast Asian monsoon climate history for the past 400 years based on textural, carbon and oxygen isotope record of a stalagmite from Yongcheon lava tube cave, Jeju Island, Kor
Publisher: Elsevier BV
Date: 10-2015
Paleoenvironmental evolution of Picos de Europa (Spain) during marine isotopic stages 5c to 3 combining glacial reconstruction, cave sedimentology and paleontological findings
Publisher: Elsevier BV
Date: 11-2020
Timing and structure of the Younger Dryas event in northern China
Publisher: Elsevier BV
Date: 05-2012
Cyclic precipitation variation on the western Loess Plateau of China during the past four centuries
Publisher: Springer Science and Business Media LLC
Date: 16-09-2014
DOI: 10.1038/SREP06381
Abstract: Precipitation variation on the Loess Plateau (LP) of China is not only important for rain-fed agriculture in this environmentally sensitive region, but also critical for the water and life securities over the whole Yellow River basin. Here we reconstruct high resolution precipitation variation on the western LP during the past 370 years by using two replicated, annually-laminated stalagmites. Spatial analysis suggests that the reconstruction can be also representative for the whole LP region. The precipitation variations show a significant quasi-50 year periodicity during the last 370 years and have an important role in determining the runoff of the middle Yellow River. The main factor controlling the decadal scale variations and long-term trend in precipitation over this region is southerly water vapour transport associated with the Asian summer monsoon. The Pacific Decadal Oscillation is also an important influence on precipitation variation in this region, as it can affect the East Asian summer monsoon and the West Pacific Subtropical High.
A high‐resolution monsoon record of millennial‐scale oscillations during Late MIS 3 from Wulu Cave, south‐west China
Publisher: Wiley
Date: 18-12-2013
DOI: 10.1002/JQS.2681
Strong coupling of centennial-scale changes of Asian monsoon and soil processes derived from stalagmite δ18O and δ13C records, southern China
Publisher: Cambridge University Press (CUP)
Date: 05-2016
DOI: 10.1016/J.YQRES.2016.02.008
Abstract: The paleoclimate application of speleothem δ 13 C is influenced by site-specific processes. Here we present four stalagmite δ 13 C records from two caves in southern China, covering early and late Marine Isotope Stage (MIS) 3 and the Holocene, to investigate the spatio-temporal pattern of calcite δ 13 C changes and the relationship with Asian monsoon (AM) variability. In each growth period, precessional- to millennial-scale changes are clear in the δ 18 O record. In contrast, millennial variability is absent in the δ 13 C record, which characterizes persistent centennial oscillations. However, centennial-scale δ 18 O variations agree well with those of δ 13 C, with a larger litude in δ 13 C changes (about twice that of δ 18 O). This suggests that soil humidity balance associated with regional hydrological circulations is important for these centennial δ 13 C changes, although evaporation-related kinetic fractionation can induce concurrent enrichments in δ 18 O and δ 13 C. In frequency, the detrended δ 18 O and δ 13 C records are coupled at a periodicity of about 300 yr during the last glacial period and 150 yr during the Holocene. Those centennial-scale δ 13 C variations are generally consistent with Greenland temperature variability, indicating a climate response over broad regions. Thus, strong co-variation of δ 18 O and δ 13 C records should have a climatic origin, even if it is lified by kinetic effects.
Central Europe temperature constrained by speleothem fluid inclusion water isotopes over the past 14,000 years
Publisher: American Association for the Advancement of Science (AAAS)
Date: 07-06-2019
Abstract: Past precipitation water sealed in stalagmites from Switzerland gives insight into temperature changes for the past 14,000 years.
Trace-element variations in an annually layered stalagmite as recorders of climatic changes and anthropogenic pollution in Central China
Publisher: Cambridge University Press (CUP)
Date: 03-2014
DOI: 10.1016/J.YQRES.2013.12.001
Abstract: We analyzed variations in the Sr/Ca, Ba/Ca, REE/Ca (REE: rare earth element), Zn/Ca, and Pb/Ca ratios preserved in an annually layered stalagmite, XL21, from central China. The stalagmite record spans the 95 year period AD 1914–2008. The Sr/Ca and Ba/Ca ratios have a significant positive correlation with the stalagmite's growth rate, suggesting that they were primarily controlled by growth-rate variations. Variations in REE/Ca ratios are consistent with local temperature changes, suggesting temperature influenced REE concentrations in the stalagmite over decadal to annual timescales. Higher temperature in this humid area can increase vegetation cover, microbial activity, and organic decomposition in the soil, resulting in enhanced pCO 2 , organic matter concentration and reduced pH, and consequently increased REE mobilization from the overlying soil layer and host rock. Higher temperatures may also increase the natural Zn mobilization from the overlying soil mediated by organic matter and consequently may have led to increased Zn retention in XL21. An increasing trend is seen in the Pb/Ca ratios from XL21 since 1985, which is consistent with increased lead production in this area, and indicates an increase in mine-derived lead pollution in the local environment over the past 30 years.
Stalagmite paleomagnetic record of a quiet mid-to-late Holocene field activity in central South America
Publisher: Springer Science and Business Media LLC
Date: 15-03-2022
DOI: 10.1038/S41467-022-28972-8
Abstract: Speleothems can provide high-quality continuous records of the direction and relative paleointensity of the geomagnetic field, combining high precision dating (with U-Th method) and rapid lock-in of their detrital magnetic particles during calcite precipitation. Paleomagnetic results for a mid-to-late Holocene stalagmite from Dona Benedita Cave in central Brazil encompass ~1900 years (3410 BP to 5310 BP, constrained by 12 U-Th ages) of paleomagnetic record from 58 s les (resolution of ~33 years). This dataset reveals angular variations of less than 0.06° yr −1 and a relatively steady paleointensity record (after calibration with geomagnetic field model) contrasting with the fast variations observed in younger speleothems from the same region under influence of the South Atlantic Anomaly. These results point to a quiescent period of the geomagnetic field during the mid-to-late Holocene in the area now comprised by the South Atlantic Anomaly, suggesting an intermittent or an absent behavior at the multi-millennial timescale.
Centennial-scale monsoon climate fluctuations from a stalagmite record during the mid-Holocene Epoch in Fulu cave of Huaping, Yunnan, China
Publisher: Springer Science and Business Media LLC
Date: 07-01-2015
Holocene climate change, permafrost and cryogenic carbonate formation: insights from a recently deglaciated, high-elevation cave in the Austrian Alps
Publisher: Copernicus GmbH
Date: 22-07-2014
Abstract: Abstract. Cryogenically formed carbonate particles represent a rather new class of speleothems whose origin is directly linked to the presence of perennial ice in the subsurface. Recent studies concluded that dating these deposits provides important time constraints on the presence and the thickness of permafrost, e.g., during the last glacial period. More precisely, these carbonates record episodes of progressive karst water freezing. Such conditions have been associated with periods of permafrost thawing allowing the infiltration of meltwater into formerly dry, frozen caves. To shed more light on the origin of the coarsely crystalline variety of these cryogenic cave carbonates – CCCcoarse for short – we examined a high-elevation cave site in the western part of the Austrian Alps which is located in an area dominated by permafrost features and transformed from an ice cave into an essentially ice-free cave during the past decade. Two side chambers of the main gallery revealed cryogenic calcite deposits whose isotopic composition indicates that they formed in in idual pools of water carved in ice which underwent very slow freezing under closed-system conditions, i.e., enclosed in ice. 230Th dating shows that most of these carbonates formed ca. 2600 yr BP. Based on comparisons with other palaeoclimate archives in the Alps this thawing episode did not occur during a climate optimum, nor did CCCcoarse form in this cave during, e.g., the Roman or the Medieval Warm Periods. Our results suggest that the occurrence of CCCcoarse, at least in mountain regions characterized by discontinuous permafrost, may be more stochastic than previously thought. Given the inherent heterogeneity of karst aquifers and the important role of localized water infiltration in modifying the thermal structure of the subsurface, we caution against attributing CCCcoarse occurrences solely to peak warming conditions, while confirming the unique significance of these deposits in providing robust age constraints on permafrost thawing episodes.
Time-scales of Differentiation from Mafic Parents to Rhyolite in North American Continental Arcs
Publisher: Oxford University Press (OUP)
Date: 09-2003
East Asian monsoon changes early in the last deglaciation and insights into the interpretation of oxygen isotope changes in the Chinese stalagmite record
Publisher: Elsevier BV
Date: 12-2020
Antarctic link with East Asian summer monsoon variability during the Heinrich Stadial–Bølling interstadial transition
Publisher: Elsevier BV
Date: 11-2016
Summer Monsoon Rainfall Variability in Central China over the Past 4700 Years and Its Possible Link to Solar Activity
Publisher: Springer Science and Business Media LLC
Date: 08-2021
Eastern North American climate in phase with fall insolation throughout the last three glacial-interglacial cycles
Publisher: Elsevier BV
Date: 09-2019
Climatic and biotic thresholds of coral-reef shutdown
Publisher: Springer Science and Business Media LLC
Date: 23-02-2015
DOI: 10.1038/NCLIMATE2541
The climate variability in northern Levant over the past 20,000 years
Publisher: American Geophysical Union (AGU)
Date: 28-10-2015
DOI: 10.1002/2015GL065397
Variation in the Asian monsoon intensity and dry–wet conditions since the Little Ice Age in central China revealed by an aragonite stalagmite
Publisher: Copernicus GmbH
Date: 10-2014
Abstract: Abstract. This paper focuses on the climate variability in central China since AD 1300, involving: (1) a well-dated, 1.5-year resolution stalagmite δ18O record from Lianhua Cave, central China (2) links of the δ18O record with regional dry–wet conditions, monsoon intensity, and temperature over eastern China (3) correlations among drought events in the Lianhua record, solar irradiation, and ENSO (El Niño–Southern Oscillation) variation. We present a highly precise, 230Th / U-dated, 1.5-year resolution δ18O record of an aragonite stalagmite (LHD1) collected from Lianhua Cave in the Wuling Mountain area of central China. The comparison of the δ18O record with the local instrumental record and historical documents indicates that (1) the stalagmite δ18O record reveals variations in the summer monsoon intensity and dry–wet conditions in the Wuling Mountain area. (2) A stronger East Asian summer monsoon (EASM) enhances the tropical monsoon trough controlled by ITCZ (Intertropical Convergence Zone), which produces higher spring quarter rainfall and isotopically light monsoonal moisture in the central China. (3) The summer quarter/spring quarter rainfall ratio in central China can be a potential indicator of the EASM strength: a lower ratio corresponds to stronger EASM and higher spring rainfall. The ratio changed from to after 1950, reflecting that the summer quarter rainfall of the study area became dominant under stronger influence of the Northwestern Pacific High. Eastern China temperatures varied with the solar activity, showing higher temperatures under stronger solar irradiation, which produced stronger summer monsoons. During Maunder, Dalton and 1900 sunspot minima, more severe drought events occurred, indicating a weakening of the summer monsoon when solar activity decreased on decadal timescales. On an interannual timescale, dry conditions in the study area prevailed under El Niño conditions, which is also supported by the spectrum analysis. Hence, our record illustrates the linkage of Asian summer monsoon precipitation to solar irradiation and ENSO: wetter conditions in the study area under stronger summer monsoon during warm periods, and vice versa. During cold periods, the Walker Circulation will shift toward the central Pacific under El Niño conditions, resulting in a further weakening of Asian summer monsoons.
Abrupt climate changes during Termination III in Southern Europe
Publisher: Proceedings of the National Academy of Sciences
Date: 05-09-2017
Abstract: We present an outstanding speleothem record that reconstructs the vegetation activity and hydrological availability during Termination III (T-III) in Southern Europe throughout δ 13 C, δ 18 O, and Mg/Ca variations. The results reveal for the North Atlantic region the sequence of abrupt stadial events during T-III, in close analogy to the Asian Monsoon changes reconstructed from Chinese speleothems. The two stadials identified in this record (S8.1 and S8.2) have similarities with Heinrich 1 and Heinrich 2 events in Termination I in terms of changes in the phasing of benthic δ 18 O, rise of semidesert pollen taxa, and ice-rafted debris release.
The Indian monsoon variability and civilization changes in the Indian subcontinent
Publisher: American Association for the Advancement of Science (AAAS)
Date: 12-2017
Abstract: Speleothem records of Indian monsoon provide climatic context to societal changes in Indian subcontinent over the last 5700 years.
Millennial‐scale precipitation changes in southern Brazil over the past 90,000 years
Publisher: American Geophysical Union (AGU)
Date: 04-12-2007
DOI: 10.1029/2007GL031149
Holocene variability of East Asian summer monsoon as viewed from the speleothem δ
Publisher:
Elsevier BV
Date:
03-2021
Publisher: Elsevier BV
Date: 03-2021
Winter precipitation changes during the Medieval Climate Anomaly and the Little Ice Age in arid Central Asia
Publisher: Elsevier BV
Date: 12-2017
(Pa-231/U-235)-(Th-230/U-238) of young mafic volcanic rocks from Nicaragua and Costa Rica and the influence of flux melting on U-series systematics of arc lavas
Publisher: No publisher found
Date: 2002
Reply to: Comments on: “Anatomy of a late Quaternary carbonate island: Constraints on timing and magnitude of sea-level fluctuations, West Caicos, Turks and Caicos Islands, BWI” by Wanless and Dravis [Quat. Sci. Rev. DOI:10.1016/j.quascirev.2020.106216]
Publisher: Elsevier BV
Date: 09-2020
Precipitation evolution of Central Asia during the last 5000 years
Publisher: SAGE Publications
Date: 06-10-2016
Abstract: Central Asia is located at the confluence of large-scale atmospheric circulation systems. However, the number of Holocene climate records is still low in most parts of this region and insufficient to allow detailed discussion and comparisons to disentangle the complex climate history and interplays between the different climatic systems. Here, we present the first stalagmite record from arid Central Asia (south-western Kyrgyzstan) by using δ 18 O, δ 13 C, and micro x-ray fluorescence (µXRF)-sulfur data spanning the last 5000 years. The cave hosting stalagmite Uluu-2 is ideally suited to identify past shifts in seasonal variations in precipitation in this part of the world. Comparison of instrumental and paleo-isotopic studies demonstrates that the Uluu-2 speleothem isotope composition faithfully records climate changes and responds to shifts in the proportion of moisture derived from mid-latitude Westerlies during the winter/spring season. The reconstructions suggest that the area was characterized by a dry climate from 4700 to 3900 yr BP, interrupted by a wet episode around 4200 yr BP. Further drier conditions also occurred between 4000 and 3500 yr BP. Wetter conditions were re-established at ca. 2500 yr BP, after another dry episode between 3000 and 2500 yr BP. With the exception of two short dry events (1150 and 1300 yr BP), the period after 1700 yr BP shows moderate to wet conditions. Regional comparisons suggest that the strength and position of the Westerly winds control climatic shifts in arid Central Asia, leading to complex local responses.
Pluvial periods in Southern Arabia over the last 1.1 million-years
Publisher: Elsevier BV
Date: 02-2020
Chinese cave records and the East Asia Summer Monsoon
Publisher: Elsevier BV
Date: 2014
Geochemical and isotopic (U, Th) variations in lake waters in the Qinghai Lake Basin, Northeast Qinghai-Tibet Plateau, China: origin and paleoenvironmental implications
Publisher: Springer Science and Business Media LLC
Date: 31-01-2019
A multiple cave deposit assessment of suitability of speleothem isotopes for reconstructing palaeo‐vegetation and palaeo‐temperature
Publisher: Wiley
Date: 11-12-2013
DOI: 10.1111/SED.12078
El Niño/Southern Oscillation and tropical Pacific climate during the last millennium
Publisher: Springer Science and Business Media LLC
Date: 07-2003
DOI: 10.1038/NATURE01779
Precise dating of abrupt shifts in the Asian Monsoon during the last deglaciation based on stalagmite data from Yamen Cave, Guizhou Province, China
Publisher: Springer Science and Business Media LLC
Date: 07-04-2010
Asian monsoon intensity coupled to Antarctic climate during Dansgaard–Oeschger 8 and Heinrich 4 glacial intervals
Publisher: Springer Science and Business Media LLC
Date: 28-11-2022
DOI: 10.1038/S43247-022-00633-0
Abstract: The transition from glacial to interglacial periods has been hypothesized to be linked to millennial-scale changes in oceanic/atmospheric circulation, but the relationships between these phenomena remain poorly constrained. Here we present a speleothem oxygen isotope record from Yongxing Cave, China, spanning 40.9 to 33.1 ka and compare this to existing Antarctic proxy records. We find that decadal-to-centennial rapid shifts in the Asian summer monsoon, Antarctic temperature, atmospheric methane and carbon dioxide are all coupled together during Dansgaard–Oeschger cycles, which may suggest an important role of the Intertropical Convergence Zone and Southern Ocean in driving the global greenhouse gas changes. Analogous to millennial-scale variations in trend, litude and internal sub-centennial-scale structures during Dansgaard–Oeschger 8 and Heinrich Stadial 4, the Younger Dryas and Heinrich Stadial 1 during the last ice termination provided critical positive feedbacks to changes in terrestrial vegetation and northern ice volume, and may have contributed to glacial to interglacial transition.
The Seasonally Altered Atmosphere Moisture Circulations With Rainfall and Rainfall Isotopes in Southwest China
Publisher: Frontiers Media SA
Date: 11-02-2022
DOI: 10.3389/FEART.2022.795857
Abstract: To interpret the climatic signals of precipitation/speleothem δ 18 O, it is critical to identify the importance of the factors affecting the precipitation δ 18 O. This study presents new stable isotope data for precipitation δ 18 O and δD in the site of Shenqi cave, southwest China, from November-2015 to October-2016 (the “Super-El Niño” event), to investigate the regional-scale climate forcing on precipitation δ 18 O. The precipitation δ 18 O, δD and d -excess have an obvious seasonality, relatively low values in the wet season and high in the dry season. The further analysis of seasonally altered LMWL and moisture circulations suggested that changes in atmosphere moisture circulations would be the key factor underlying the precipitation/speleothem δ 18 O fluctuations in our study area at least on seasonal timescales. Combined with the seasonal-monthly variations of the IsoGSM δ 18 O, GPCP/CRU rainfall and NCEP/NCAR moisture fluxes, we detected that the super-El Niño of 2016 have changed the distributions of monthly rainfall in wet season through the Western Pacific Subtropical High, but not mainly the precipitation isotopic compositions and moisture circulations in our study area.
Remote vs. local control on the Preboreal Asian hydroclimate and soil processes recorded by an annually-laminated stalagmite from Daoguan Cave, southern China
Publisher: Elsevier BV
Date: 09-2017
Summer monsoon precipitation variations in central China over the past 750years derived from a high-resolution absolute-dated stalagmite
Publisher: Elsevier BV
Date: 09-2009
Deep-Sea Coral Evidence for Rapid Change in Ventilation of the Deep North Atlantic 15,400 Years Ago
Publisher: American Association for the Advancement of Science (AAAS)
Date: 05-1998
DOI: 10.1126/SCIENCE.280.5364.725
Abstract: Coupled radiocarbon and thorium-230 dates from benthic coral species reveal that the ventilation rate of the North Atlantic upper deep water varied greatly during the last deglaciation. Radiocarbon ages in several corals of the same age, 15.41 ± 0.17 thousand years, and nearly the same depth, 1800 meters, in the western North Atlantic Ocean increased by as much as 670 years during the 30- to 160-year life spans of the s les. Cadmium/calcium ratios in one coral imply that the nutrient content of these deep waters also increased. Our data show that the deep ocean changed on decadal-centennial time scales during rapid changes in the surface ocean and the atmosphere.
Sixty-year quasi-period of the Asian monsoon around the Last Interglacial derived from an annually resolved stalagmite δ18O record
Publisher: Elsevier BV
Date: 03-2020
Uranium-series Dating of Marine and Lacustrine Carbonates
Publisher: Mineralogical Society of America
Date: 2003
DOI: 10.2113/0520363
Hydro-climate characteristics of the karst system of Wintimdouine cave (Western High Atlas, Morocco): monitoring and implications for paleoclimate research
Publisher: Springer Science and Business Media LLC
Date: 08-2019
Potential role of winter rainfall in explaining increased moisture in the Mediterranean and Middle East during periods of maximum orbitally-forced insolation seasonality
Publisher: Springer Science and Business Media LLC
Date: 02-03-2013
Evidence for solar cycles in a late Holocene speleothem record from Dongge Cave, China
Publisher: Springer Science and Business Media LLC
Date: 04-06-2014
DOI: 10.1038/SREP05159
Effect of precipitation seasonality on annual oxygen isotopic composition in the area of spring persistent rain in southeastern China and its paleoclimatic implication
Publisher: Copernicus GmbH
Date: 30-01-2020
Abstract: Abstract. This study examines the seasonality of precipitation amount and δ18O over the monsoon region of China (MRC). We found that the precipitation amount associated with the East Asian summer monsoon (EASM) in the spring persistent rain (SPR) region is equivalent to that of the nonsummer monsoon (NSM). The latter contributes ∼50 % to amount-weighted annual δ18O values, in contrast with other areas in the MRC, where the δ18O of annual precipitation is dominated by EASM precipitation. Interannual relationships between the El Niño–Southern Oscillation (ENSO) index, simulated δ18O data from IsoGSM, and seasonal precipitation amount in the SPR region were also examined. We found that on interannual timescales, the seasonality of precipitation amount (EASM ∕ NSM ratio) was modulated by ENSO and primarily influences the variability of amount-weighted annual precipitation δ18O values in the SPR region, although integrated regional convection and moisture source and transport distance may also play subordinate roles. During El Niño (La Niña) phases, less (more) EASM and more (less) NSM precipitation leading to lower (higher) EASM ∕ NSM precipitation amount ratios results in higher (lower) amount-weighted annual precipitation δ18O values and, consequently, in higher (lower) speleothem δ18O values. Characterizing spatial differences in seasonal precipitation is, therefore, key to correctly interpreting speleothem δ18O records from the MRC.
Connecting the Greenland ice-core and U∕Th timescales via cosmogenic radionuclides: testing the synchroneity of Dansgaard–Oeschger events
Publisher: Copernicus GmbH
Date: 20-11-2018
Abstract: Abstract. During the last glacial period Northern Hemisphere climate was characterized by extreme and abrupt climate changes, so-called Dansgaard–Oeschger (DO) events. Most clearly observed as temperature changes in Greenland ice-core records, their climatic imprint was geographically widespread. However, the temporal relation between DO events in Greenland and other regions is uncertain due to the chronological uncertainties of each archive, limiting our ability to test hypotheses of synchronous change. In contrast, the assumption of direct synchrony of climate changes forms the basis of many timescales. Here, we use cosmogenic radionuclides (10Be, 36Cl, 14C) to link Greenland ice-core records to U∕Th-dated speleothems, quantify offsets between the two timescales, and improve their absolute dating back to 45 000 years ago. This approach allows us to test the assumption that DO events occurred synchronously between Greenland ice-core and tropical speleothem records with unprecedented precision. We find that the onset of DO events occurs within synchronization uncertainties in all investigated records. Importantly, we demonstrate that local discrepancies remain in the temporal development of rapid climate change for specific events and speleothems. These may either be related to the location of proxy records relative to the shifting atmospheric fronts or to underestimated U∕Th dating uncertainties. Our study thus highlights the potential for misleading interpretations of the Earth system when applying the common practice of climate wiggle matching.
The Taravilla lake and tufa deposits (Central Iberian Range, Spain) as palaeohydrological and palaeoclimatic indicators
Publisher: Elsevier BV
Date: 03-2008
Climate change patterns in Amazonia and biodiversity
Publisher: Springer Science and Business Media LLC
Date: 29-01-2013
DOI: 10.1038/NCOMMS2415
Abstract: Precise characterization of hydroclimate variability in Amazonia on various timescales is critical to understanding the link between climate change and bio ersity. Here we present absolute-dated speleothem oxygen isotope records that characterize hydroclimate variation in western and eastern Amazonia over the past 250 and 20 ka, respectively. Although our records demonstrate the coherent millennial-scale precipitation variability across tropical-subtropical South America, the orbital-scale precipitation variability between western and eastern Amazonia exhibits a quasi-dipole pattern. During the last glacial period, our records imply a modest increase in precipitation amount in western Amazonia but a significant drying in eastern Amazonia, suggesting that higher bio ersity in western Amazonia, contrary to 'Refugia Hypothesis', is maintained under relatively stable climatic conditions. In contrast, the glacial-interglacial climatic perturbations might have been instances of loss rather than gain in bio ersity in eastern Amazonia, where forests may have been more susceptible to fragmentation in response to larger swings in hydroclimate.
Uranium and thorium isotopic and concentration measurements by magnetic sector inductively coupled plasma mass spectrometry
Publisher: Elsevier BV
Date: 05-2002
Holocene and Eemian climatic optima in the Korean Peninsula based on textural and carbon isotopic records from the stalagmite of the Daeya Cave, South Korea
Publisher: Elsevier BV
Date: 05-2011
Woo et al. reply
Publisher: Springer Science and Business Media LLC
Date: 30-09-2015
DOI: 10.1038/NATURE14977
A record of wet glacial stages and dry interglacial stages over the last 560 kyr from a standing massive stalagmite in Carlsbad Cavern, New Mexico, USA
Publisher: Elsevier BV
Date: 11-2015
New insights towards an integrated understanding of NE Asian monsoon during mid to late Holocene
Publisher: Elsevier BV
Date: 02-2021
A penultimate glacial monsoon record from Hulu Cave and two-phase glacial terminations
Publisher: Geological Society of America
Date: 2006
DOI: 10.1130/G22289.1
The Holocene Asian Monsoon: Links to Solar Changes and North Atlantic Climate
Publisher: American Association for the Advancement of Science (AAAS)
Date: 06-05-2005
Abstract: A 5-year-resolution absolute-dated oxygen isotope record from Dongge Cave, southern China, provides a continuous history of the Asian monsoon over the past 9000 years. Although the record broadly follows summer insolation, it is punctuated by eight weak monsoon events lasting ∼1 to 5 centuries. One correlates with the “8200-year” event, another with the collapse of the Chinese Neolithic culture, and most with North Atlantic ice-rafting events. Cross-correlation of the decadal- to centennial-scale monsoon record with the atmospheric carbon-14 record shows that some, but not all, of the monsoon variability at these frequencies results from changes in solar output.
Centennial- to decadal-scale monsoon precipitation variations in the upper Hanjiang River region, China over the past 6650 years
Publisher: Elsevier BV
Date: 2018
High-resolution variability of the South American summer monsoon over the last seven millennia: insights from a speleothem record from the central Peruvian Andes
Publisher: Elsevier BV
Date: 09-2013
Corrigendum to “Sixty-year quasi-period of the Asian monsoon around the Last Interglacial derived from an annually resolved stalagmite δ18O record” [Palaeogeogr. Palaeoclimatol. Palaeoecol. 541 (2020)
Publisher: Elsevier BV
Date: 2021
Oldest Dryas hydroclimate reorganization in the eastern Iberian Peninsula after the iceberg discharges of Heinrich Event 1
Publisher: Cambridge University Press (CUP)
Date: 13-01-2021
DOI: 10.1017/QUA.2020.112
Abstract: This study examines the first precisely dated and temporally highly resolved speleothem record from Iberia that reconstructs the Oldest Dryas (OD). The onset of cold conditions in the study area, contemporary with the beginning of Heinrich Stadial 1, is recorded at 18.13 ± 0.08 ka, with a pronounced drop of 6.1‰ in δ 13 C in 250 years. Henceforth, stadial conditions depict a period of instability in the Atlantic Meridional Overturning Circulation, peaking in freshwater input from iceberg melting during Heinrich Event 1. Anomalies in the δ 18 O of the stalagmite attributed to such a freshwater event are found from 16.17 to 15.89 ka. Such absolute dates given to the onset of the OD in Iberia and to the main iceberg discharges are reliable anchor points for non-absolute chronologies. Two periods are identified in the OD: OD-a (18.13–16.17 ka) is characterized by wet conditions and a faster growth rate, and OD-b (15.89–14.81 ka) exhibits relative dryness and a slower growth rate. The sudden release of fresh water is considered to be the reason for the disruption of rainfall patterns in eastern Iberia. The present study also highlights the existence of heterogeneous and complex hydrological conditions during the OD in Iberia when both Atlantic and Mediterranean realms are considered.
Stalagmite evidence from Belize indicating significant droughts at the time of Preclassic Abandonment, the Maya Hiatus, and the Classic Maya collapse
Publisher: Elsevier BV
Date: 06-2007
Three-phased Heinrich Stadial 4 recorded in NE Brazil stalagmites
Publisher: Elsevier BV
Date: 03-2019
Rapid forearc uplift and subsidence caused by impinging bathymetric features: Examples from the New Hebrides and Solomon arcs
Publisher: American Geophysical Union (AGU)
Date: 15-11-2005
DOI: 10.1029/2004TC001650
Author Correction: Climate variations of Central Asia on orbital to millennial timescales
Publisher: Springer Science and Business Media LLC
Date: 21-06-2021
DOI: 10.1038/S41598-021-92496-2
Abstract: An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Late Holocene droughts in the Fertile Crescent recorded in a speleothem from northern Iraq
Publisher: American Geophysical Union (AGU)
Date: 15-02-2017
DOI: 10.1002/2016GL071786
The climatic cyclicity in semiarid‐arid central Asia over the past 500,000 years
Publisher: American Geophysical Union (AGU)
Date: 2012
DOI: 10.1029/2011GL050202
A 3000-yr Annually Laminated Stalagmite Record of the Last Glacial Maximum from Hulu Cave, China
Publisher: Cambridge University Press (CUP)
Date: 03-2015
DOI: 10.1016/J.YQRES.2015.01.003
Abstract: A high-resolution, annual layer-counted and 230 Th-dated multi-proxy record is constructed from a stalagmite in Hulu Cave, China. These proxies, including δ 18 O, annual layer thickness (ALT), gray level (GL) and Sr/Ca, cover a time span of ~ 3000 yr from 21 to 24 ka. The physical proxies (ALT and GL) and the geochemical index (Sr/Ca), all primarily reflecting karst hydrological processes, vary in concert and their coherence is supported by wavelet analyses. Variations in the δ 18 O data agree with fluctuations in the ALT and Sr/Ca records on multi-decadal to centennial scales, suggesting that the Hulu δ 18 O signal is strongly associated with varying local rainfall amounts on short timescales. A monsoon failure event at ~ 22.2 ka correlates with a decrease in tropical rainfall, a reduction in global CH 4 and an ice-rafted event in the North Atlantic. This correlation highlights roles of the Asian monsoon and tropical hydrological cycle in modulating global CH 4, because the high-latitude emission was inhibited during the Last Glacial Maximum (LGM). Spectral analysis of the δ 18 O record displays peaks at periodicities of 139, 59, 53, 43, 30, 23 and 19"15 yr. The absence of typical centennial solar cycles may be related to muted changes in ocean circulation during the LGM.
Solar forcing of Holocene droughts in a stalagmite record from West Virginia in east‐central North America
Publisher: American Geophysical Union (AGU)
Date: 09-2008
DOI: 10.1029/2008GL034971
Milankovitch theory and monsoon
Publisher: Elsevier BV
Date: 11-2022
High-precision U-series dating of Locality 1 at Zhoukoudian, China
Publisher: Elsevier BV
Date: 12-2001
Millennial-scale variability in the local radiocarbon reservoir age of south Florida during the Holocene
Publisher: Elsevier BV
Date: 10-2017
The record of paleoclimatic change from stalagmites and the determination of termination II in the south of Guizhou Province, China
Publisher: Springer Science and Business Media LLC
Date: 2004
DOI: 10.1360/01YD0517
Late Palaeolithic cave art and permafrost in the Southern Ural
Publisher: Springer Science and Business Media LLC
Date: 13-08-2018
DOI: 10.1038/S41598-018-30049-W
Abstract: Shulgan-Tash (also known as Kapova) cave located on the western slope of the Ural Mountains (Russia) is the easternmost European cave art monument of late Palaeolithic age. Radiocarbon dates from cultural layers in the cave suggest an age of about 16.3 to 19.6 ka (cal BP), but dates directly on the paintings were not obtained. In order to constrain the age of this art using an independent method, we performed detailed 230 Th-U dating of calcite flowstone underlying and overgrowing the paintings at 22 sites in three halls of the cave. The youngest age for the underlying calcite (i.e., the maximum age of the cave art) is 36.4 ± 0.1 ka, and the oldest overlying calcite (constraining the minimum age of the cave art) is 14.5 ± 0.04 ka. The ca. 21.9 ka-long hiatus in calcite deposition during which the paintings were made is attributed to regional permafrost conditions and sub-zero temperatures inside the cave during Marine Isotope Stage (MIS) 2. This is supported by s les of cryogenic cave calcite, which document seven episodes of freezing and thawing of permafrost associated with stadials and interstadials of MIS 3, respectively.
Milankovitch-paced Termination II in a Nevada speleothem?
Publisher: American Geophysical Union (AGU)
Date: 17-09-2011
DOI: 10.1029/2011GL048560
Strong coupling of Asian Monsoon and Antarctic climates on sub-orbital timescales
Publisher: Springer Science and Business Media LLC
Date: 08-09-2016
DOI: 10.1038/SREP32995
Abstract: There is increasing evidence that millennial-scale climate variability played an active role on orbital-scale climate changes, but the mechanism for this remains unclear. A 230 Th-dated stalagmite δ 18 O record between 88 and 22 thousand years (ka) ago from Yongxing Cave in central China characterizes changes in Asian monsoon (AM) strength. After removing the 65°N insolation signal from our record, the δ 18 O residue is strongly anti-phased with Antarctic temperature variability on sub-orbital timescales during the Marine Isotope Stage (MIS) 3. Furthermore, once the ice volume signal from Antarctic ice core records were removed and extrapolated back to the last two glacial-interglacial cycles, we observe a linear relationship for both short- and long-duration events between Asian and Antarctic climate changes. This provides the robust evidence of a link between northern and southern hemisphere climates that operates through changes in atmospheric circulation. We find that the weakest monsoon closely associated with the warmest Antarctic event always occurred during the Terminations. This finding, along with similar shifts in the opal flux record, suggests that millennial-scale events play a key role in driving the deglaciation through positive feedbacks associated with enhanced upwelling and increasing CO 2 .
Variations in triple oxygen isotope of speleothems from the Asian monsoon region reveal moisture sources over the past 300 years
Publisher: Springer Science and Business Media LLC
Date: 18-10-2023
The Holocene Indian monsoon variability over the southern Tibetan Plateau and its teleconnections
Publisher: Elsevier BV
Date: 06-2012
Changing chemistry of particulate manganese in the near- and far-field hydrothermal plumes from 15°S East Pacific Rise and its influence on metal scavenging
Publisher: Elsevier BV
Date: 05-2021
Upper Pleistocene interstratal piping-cave speleogenesis: The Seso Cave System (Central Pyrenees, Northern Spain)
Publisher: Elsevier BV
Date: 2015
Stalagmite-inferred centennial variability of the Asian summer monsoon in southwest China between 58 and 79 ka BP
Publisher: Elsevier BV
Date: 03-2017
Comparison of mass spectrometry and spectroscopy methods applied to measurements of water triple oxygen isotopic compositions
Publisher: Science China Press., Co. Ltd.
Date: 19-10-2021
DOI: 10.1360/TB-2021-0773
Geochemistry of speleothems affected by aragonite to calcite recrystallization – Potential inheritance from the precursor mineral
Publisher: Elsevier BV
Date: 03-2017
The East Asian Monsoon During MIS 2 Expressed in a Speleothem δ18O Record From Jintanwan Cave, Hunan, China
Publisher: Cambridge University Press (CUP)
Date: 05-2010
DOI: 10.1016/J.YQRES.2010.01.003
Abstract: Stalagmite J1 from Jintanwan Cave, Hunan, China, provides a precisely dated, decadally resolved δ 18 O proxy record of paleoclimatic changes associated with the East Asian monsoon from ∽29.5 to 14.7 ka and from ∽12.9 to 11.0 ka. At the time of the last glacial maximum (LGM), the East Asian summer monsoon weakened and then strengthened in response to changes in Northern Hemisphere insolation. As the ice sheets retreated the East Asian summer monsoon weakened, especially during Heinrich event H1, when atmospheric and oceanic teleconnections transferred the climatic changes around the North Atlantic to the monsoonal regions of Eastern Asia. A depositional hiatus between ∽14.7 and 12.9 ka leaves the deglacial record incomplete, but an abrupt shift in δ 18 O values at ∽11.5 ka marks the end of the Younger Dryas and the transition into the Holocene. Comparisons of the J1 record to other Chinese speleothem records indicate synchronous climatic changes throughout monsoonal China. Further comparisons to a speleothem record from western Asia (Socotra Island) and to Greenland ice cores support hemispherical-scale paleoclimatic change. Spectral and wavelet analyses reveal centennial- and decadal-scale periodicities that correspond to solar frequencies and to oscillations in atmospheric and oceanic circulation.
Inter-relationship and environmental significance of stalagmite δ13C and δ18O records from Zhenzhu Cave, north China, over the last 130 ka
Publisher: Elsevier BV
Date: 04-2020
The GEOTRACES Intermediate Data Product 2017
Publisher: Elsevier BV
Date: 08-2018
The Global Paleomonsoon as seen through speleothem records from Asia and the Americas
Publisher: Springer Science and Business Media LLC
Date: 05-05-2012
Quantitative temperature reconstruction based on growth rate of annually-layered stalagmite: a case study from central China
Publisher: Elsevier BV
Date: 07-2013
Gradual South‐North Climate Transition in the Atlantic Realm Within the Younger Dryas
Publisher: American Geophysical Union (AGU)
Date: 21-04-2021
DOI: 10.1029/2021GL092620
Abstract: The abrupt climate event Younger Dryas (YD) has been extensively studied however, its structure is still poorly understood. Climate in northeastern Brazil is very sensitive to the latitudinal position of the intertropical convergence zone (ITCZ) associated with abrupt climate change in the Atlantic. Here, we report changes in the ITCZ position within the YD by using precise speleothem multiproxy records from northeastern Brazil. We provide evidence for a gradual northward migration of the ITCZ preceding poleward shifts of the westerlies and the polar front in northern high latitudes within the YD. This can be attributed to gradual increase in atmospheric CO 2 concentration as a consequence of the weakening Atlantic Meridional Overturning Circulation (AMOC). We suggest that a persistent increase in atmospheric CO 2 might have triggered a resumption of the AMOC and reorganization of the atmosphere circulation in the Atlantic during the mid‐YD.
High-latitude forcing of interhemispheric anti-phased precipitation during the last glacial-interglacial cycle
Publisher: Elsevier BV
Date: 08-2006
A multi-proxy stalagmite record from northwestern Namibia of regional drying with increasing global-scale warmth over the last 47 kyr: The interplay of a globally shifting ITCZ with regional currents,
Publisher: Elsevier BV
Date: 11-2016
A high-resolution fluid inclusion δ18O record from a stalagmite in SW France: modern calibration and comparison with multiple proxies
Publisher: Elsevier BV
Date: 02-2015
Paleovegetation seesaw in Brazil since the Late Pleistocene: A multiproxy study of two biomes
Publisher: Elsevier BV
Date: 06-2021
Rapid northern hemisphere ice sheet melting during the penultimate deglaciation
Publisher: Springer Science and Business Media LLC
Date: 02-07-2022
DOI: 10.1038/S41467-022-31619-3
Abstract: The rate and consequences of future high latitude ice sheet retreat remain a major concern given ongoing anthropogenic warming. Here, new precisely dated stalagmite data from NW Iberia provide the first direct, high-resolution records of periods of rapid melting of Northern Hemisphere ice sheets during the penultimate deglaciation. These records reveal the penultimate deglaciation initiated with rapid century-scale meltwater pulses which subsequently trigger abrupt coolings of air temperature in NW Iberia consistent with freshwater-induced AMOC slowdowns. The first of these AMOC slowdowns, 600-year duration, was shorter than Heinrich 1 of the last deglaciation. Although similar insolation forcing initiated the last two deglaciations, the more rapid and sustained rate of freshening in the eastern North Atlantic penultimate deglaciation likely reflects a larger volume of ice stored in the marine-based Eurasian Ice sheet during the penultimate glacial in contrast to the land-based ice sheet on North America as during the last glacial.
Correction for Bartolomé et al., Hydrological change in Southern Europe responding to increasing North Atlantic overturning during Greenland Stadial 1
Publisher: Proceedings of the National Academy of Sciences
Date: 24-06-2015
Three thousand years of extreme rainfall events recorded in stalagmites from Spring Valley Caverns, Minnesota
Publisher: Elsevier BV
Date: 11-2010
Coupling of Indo-Pacific climate variability over the last millennium
Publisher: Springer Science and Business Media LLC
Date: 09-03-2020
DOI: 10.1038/S41586-020-2084-4
Abstract: The Indian Ocean Dipole (IOD) affects climate and rainfall across the world, and most severely in nations surrounding the Indian Ocean
Sea-level variability over five glacial cycles
Publisher: Springer Science and Business Media LLC
Date: 25-09-2014
DOI: 10.1038/NCOMMS6076
Abstract: Research on global ice-volume changes during Pleistocene glacial cycles is hindered by a lack of detailed sea-level records for time intervals older than the last interglacial. Here we present the first robustly dated, continuous and highly resolved records of Red Sea sea level and rates of sea-level change over the last 500,000 years, based on tight synchronization to an Asian monsoon record. We observe maximum 'natural' (pre-anthropogenic forcing) sea-level rise rates below 2 m per century following periods with up to twice present-day ice volumes, and substantially higher rise rates for greater ice volumes. We also find that maximum sea-level rise rates were attained within 2 kyr of the onset of deglaciations, for 85% of such events. Finally, multivariate regressions of orbital parameters, sea-level and monsoon records suggest that major meltwater pulses account for millennial-scale variability and insolation-lagged responses in Asian monsoon records.
A high-resolution, absolute-dated Holocene and deglacial Asian monsoon record from Dongge Cave, China
Publisher: Elsevier BV
Date: 30-04-2005
A 200-year annually laminated stalagmite record of precipitation seasonality in southeastern China and its linkages to ENSO and PDO
Publisher: Springer Science and Business Media LLC
Date: 17-08-2018
DOI: 10.1038/S41598-018-30112-6
Abstract: In southeastern China (SEC), the precipitation amount produced by the East Asian summer monsoon (EASM) is almost equivalent to that during the non-summer monsoon (NSM) period, both of them significantly affecting agriculture and socioeconomy. Here, we present a seasonally-resolved stalagmite δ 18 O record (δ 18 O s ) for the interval 1810–2009 AD from E’mei cave, Jiangxi Province, SEC. The comparison between δ 18 O s and instrumental data indicates that the δ 18 O s variability is primarily controlled by the precipitation seasonality (i.e., the ratio of EASM/NSM precipitation) modulated by the El Niño/Southern Oscillation (ENSO) on interannual to interdecadal timescales. Higher (lower) δ 18 O s values thereby correspond to lower (higher) EASM/NSM ratios associated with El Niño (La Niña) events. Significant correlations with ENSO and the Pacific Decadal Oscillation (PDO) indicate that the precipitation seasonality in SEC is remarkably influenced by ocean-atmosphere interactions, with lower (higher) EASM/NSM ratios during warm (cold) phases of ENSO/PDO. The progressive increase in δ 18 O s since 2005 AD may reflect a strengthening of the central Pacific El Niño under continued anthropogenic global warming. The relationship between seasonal precipitation and δ 18 O s with ENSO/PDO requires further studies.
U-Th dating of deep-sea corals
Publisher: Elsevier BV
Date: 07-2000
Lake Level Reconstruction for 12.8–2.3 ka of the Ngangla Ring Tso Closed-Basin Lake System, Southwest Tibetan Plateau
Publisher: Cambridge University Press (CUP)
Date: 2015
DOI: 10.1016/J.YQRES.2014.07.012
Abstract: We present a shoreline-based, millennial-scale record of lake-level changes spanning 12.8–2.3 ka for a large closed-basin lake system on the southwestern Tibetan Plateau. Fifty-three radiocarbon and eight U–Th series ages of tufa and beach cement provide age control on paleoshorelines ringing the basin, supplemented by nineteen ages from shell and aquatic plant material from natural exposures generally recording lake regressions. Our results show that paleo-Ngangla Ring Tso exceeded modern lake level (4727 m asl) continuously between ~ 12.8 and 2.3 ka. The lake was at its highstand 135 m (4862 m asl) above the modern lake from 10.3 ka to 8.6 ka. This is similar to other closed-basin lakes in western Tibet, and coincides with peak Northern Hemisphere summer insolation and peak Indian Summer Monsoon intensity. The lake experienced a series of millennial-scale oscillations centered on 11.5, 10.8, 8.3, 5.9 and 3.6 ka, consistent with weak monsoon events in proxy records of the Indian Summer Monsoon. It is unclear whether these events were forced by North Atlantic or Indian Ocean conditions, but based on the abrupt lake-level regressions recorded for Ngangla Ring Tso, they resulted in significant periodic reductions in rainfall over the western Tibetan Plateau throughout the Holocene.
Noble gas based temperature reconstruction on a Swiss stalagmite from the last glacial–interglacial transition and its comparison with other climate records
Publisher: Elsevier BV
Date: 08-2018
A High-Resolution Absolute-Dated Late Pleistocene Monsoon Record from Hulu Cave, China
Publisher: American Association for the Advancement of Science (AAAS)
Date: 14-12-2001
Abstract: Oxygen isotope records of five stalagmites from Hulu Cave near Nanjing bear a remarkable resemblance to oxygen isotope records from Greenland ice cores, suggesting that East Asian Monsoon intensity changed in concert with Greenland temperature between 11,000 and 75,000 years before the present (yr. B.P.). Between 11,000 and 30,000 yr. B.P., the timing of changes in the monsoon, as established with 230 Th dates, generally agrees with the timing of temperature changes from the Greenland Ice Sheet Project Two (GISP2) core, which supports GISP2's chronology in this interval. Our record links North Atlantic climate with the meridional transport of heat and moisture from the warmest part of the ocean where the summer East Asian Monsoon originates.
Paleoclimate and growth rates of speleothems in the northwestern Iberian Peninsula over the last two glacial cycles
Publisher: Cambridge University Press (CUP)
Date: 09-2013
DOI: 10.1016/J.YQRES.2013.05.002
Abstract: Speleothem growth requires humid climates sufficiently warm to stimulate soil CO 2 production by plants. We compile 283 U/Th dates on 21 stalagmites from six cave systems in the NW coast of Spain to evaluate if there are patterns in stalagmite growth that are evidence of climatic forcing. In the oldest stalagmites, from marine oxygen isotope stage (MIS) 7–5, growth persists through the glacial period. Hiatuses and major reductions in growth rate occur during extreme minima in summer insolation. Stalagmites active during the last interglaciation cease growth at the MIS 5–4 boundary (74 ka), when regional sea-surface temperature cooled significantly. During MIS 3, only two stalagmites grew rates were highest between 50 and 60 ka during the maximum in summer insolation. One stalagmite grew briefly at 41 ka, 36.5 and 28.6 ka, all during warm phases of the Dansgaard–Oeschger cycles. A pronounced Holocene optimum in stalagmite growth occurs from 9 to 6 ka. The cessation of most growth by 4.1 ka, coincident with broad increases in aridity over the Mediterranean and areas influenced by the North African Monsoon, suggest that regions such as NW Spain, with dominant Atlantic moisture sources, also experienced increased aridity at this time.
Investigating the 8.2 ka event in northwestern Madagascar: Insight from data–model comparisons
Publisher: Elsevier BV
Date: 2019
Isotopic and lithologic variations of one precisely-dated stalagmite across the Medieval/LIA period from Heilong Cave, central China
Publisher: Copernicus GmbH
Date: 11-10-2012
Abstract: Abstract. Lithologic and isotopic changes of one stalagmite (224 mm in length) from Heilong Cave, Central China, are investigated here in order to explore multiple proxies of monsoon climate. High uranium concentrations (6–10 ppm) ensure Th-230 dates precisely and resultant chronology ranges from ~790 to 1780 AD across the Medieval Warm Period (MWP) to Little Ice Age (LIA). Annually resolved oxygen and carbon isotopic data, gray level and elemental Sr are highly related to macroscopic lithologic changes. A lamination sequence is composed of alternations of white-porous and dark-compact calcite clearly discerned on the polished surface. The dark-compact laminae have low values of gray level, high Sr and δ13C values, indicating periods of low growth rate under dry climate conditions, and vice versa for the white-porous laminae. This suggests that changes in hydrology, matter input of drip water and crystallization process were controlled by cave environments and climates. The alternation of dry and wet periods with a significant periodicity of ~90 yr, as indicated by spectral analyses of the multiple proxies, is further supported by a reconstructed precipitation index from historical documents and instrumental data extending back to 1470 AD. A strong coherence between monsoon proxy of calcite δ18O and the other proxies was observed during the LIA but not during the MWP. This is likely due to changes in atmospheric circulation pattern at the boundary of MWP/LIA. When the Intertropical Convergence Zone shifted southward during the LIA, summer monsoon precipitation at the cave site was probably dominated by the Mei-Yu, resulting in water vapor mainly originated from adjacent oceanic sources.
Insights into the speleogenesis of Ejulve cave (Iberian Range, NE Spain): quaternary hydrothermal karstification?
Publisher: Springer Science and Business Media LLC
Date: 11-06-2019
High-frequency shifts in the Indian summer monsoon following termination of the YD event
Publisher: Elsevier BV
Date: 05-2021
A NEW RECORD OF THE LATE PLEISTOCENE CORALPOCILLOPORA PALMATAFROM THE DRY TORTUGAS, FLORIDA REEF TRACT, USA
Publisher: Society for Sedimentary Geology
Date: 12-2015
Speleothem record of geomagnetic South Atlantic Anomaly recurrence
Publisher: Proceedings of the National Academy of Sciences
Date: 10-12-2018
Abstract: The diminishing strength of the Earth’s magnetic dipole over recent millennia is accompanied by the increasing prominence of the geomagnetic South Atlantic Anomaly (SAA), which spreads over the South Atlantic Ocean and South America. The longevity of this feature at millennial timescales is elusive because of the scarcity of continuous geomagnetic data for the region. Here, we report a unique geomagnetic record for the last ∼1500 y that combines the data of two well-dated stalagmites from Pau d’Alho cave, located close to the present-day minimum of the anomaly in central South America. Magnetic directions and relative paleointensity data for both stalagmites are generally consistent and agree with historical data from the last 500 y. Before 1500 CE, the data adhere to the geomagnetic model ARCH3K.1, which is derived solely from archeomagnetic data. Our observations indicate rapid directional variations ( .1°/y) from approximately 860 to 960 CE and approximately 1450 to 1750 CE. A similar pattern of rapid directional variation observed from South Africa precedes the South American record by 224 ± 50 y. These results confirm that fast geomagnetic field variations linked to the SAA are a recurrent feature in the region. We develop synthetic models of reversed magnetic flux patches at the core–mantle boundary and calculate their expression at the Earth’s surface. The models that qualitatively resemble the observational data involve westward (and southward) migration of midlatitude patches, combined with their expansion and intensification.
The SISAL database: a global resource to document oxygen and carbon isotope records from speleothems
Publisher: Copernicus GmbH
Date: 14-09-0030
DOI: 10.5194/ESSD-10-1687-2018
Abstract: Abstract. Stable isotope records from speleothems provide information on past climate changes, most particularly information that can be used to reconstruct past changes in precipitation and atmospheric circulation. These records are increasingly being used to provide “out-of-s le” evaluations of isotope-enabled climate models. SISAL (Speleothem Isotope Synthesis and Analysis) is an international working group of the Past Global Changes (PAGES) project. The working group aims to provide a comprehensive compilation of speleothem isotope records for climate reconstruction and model evaluation. The SISAL database contains data for in idual speleothems, grouped by cave system. Stable isotopes of oxygen and carbon (δ18O, δ13C) measurements are referenced by distance from the top or bottom of the speleothem. Additional tables provide information on dating, including information on the dates used to construct the original age model and sufficient information to assess the quality of each data set and to erect a standardized chronology across different speleothems. The metadata table provides location information, information on the full range of measurements carried out on each speleothem and information on the cave system that is relevant to the interpretation of the records, as well as citations for both publications and archived data. The compiled data are available at 0.17864/1947.147.
Relationships between climate change, human environmental impact, and megafaunal extinction inferred from a 4000-year multi-proxy record from a stalagmite from northwestern Madagascar
Publisher: Elsevier BV
Date: 04-2020
Ocean-atmosphere interconnections from the last interglacial to the early glacial: An integration of marine and cave records in the Iberian region
Publisher: Elsevier BV
Date: 12-2019
Implications of stalagmite density for past climate change: An example from stalagmite growth during the last deglaciation from Wanxiang Cave, western Loess Plateau
Publisher: Springer Science and Business Media LLC
Date: 12-2010
A detailed comparison of Asian Monsoon intensity and Greenland temperature during the Allerød and Younger Dryas events
Publisher: Elsevier BV
Date: 08-2008
Sea-level history and tectonic uplift during the last-interglacial period (LIG): Inferred from the Bab al-Mandab coral reef terraces, southern Red Sea
Publisher: Elsevier BV
Date: 02-2018
The nature of annual lamination in carbonate flowstones from non-karstic fractures, Vinschgau (northern Italy)
Publisher: Elsevier BV
Date: 05-2017
Anomalously high δD and micro-scale hydrogen isotope heterogeneities in the mantle: Ion microprobe analysis of amiboles from peridotite xenoliths at Nushan, eastern China
Publisher: Springer Science and Business Media LLC
Date: 03-2001
DOI: 10.1007/BF03187269
Control of insolation on stalagmite growth, rainfall, and migration of the tropical rain belt in northern Namibia over the last 100 kyr, as suggested by a rare MIS 5b-5c stalagmite from Dante Cave
Publisher: Elsevier BV
Date: 12-2019
Relationship between the Asian summer monsoon circulation and speleothem δ18O of Xiaobailong cave
Publisher: Springer Science and Business Media LLC
Date: 12-09-2019
Abrupt changes in Indian summer monsoon strength during the last ~900 years and their linkages to socio-economic conditions in the Indian subcontinent
Publisher: Elsevier BV
Date: 12-2019
Onset and termination of Heinrich Stadial 4 and the underlying climate dynamics
Publisher: Springer Science and Business Media LLC
Date: 08-11-2021
DOI: 10.1038/S43247-021-00304-6
Abstract: Heinrich Stadial 4 during the last glacial period was marked by severe cooling at northern high latitudes along with the attendant changes in Asian Monsoon (Chinese Stadial 4) and South American Monsoon (South American Stadial 4). Here we present improved constraints on timings of Heinrich/Chinese/South American Stadial 4 onset and termination at sub-centennial precision based on speleothem records. We show that their initial onsets were essentially synchronous (40.20 ± 0.08 thousand years ago) and led the Antarctic warming by ~300 years. The Heinrich/Chinese Stadial 4 termination commenced at 38.34 ± 0.07 thousand years ago following a centennial-scale reduction in the Amazon River runoff and a poleward shift of the Southern Westerly wind belt. These two precursor events may have contributed to a reduced Amazon Plume Region and an enhanced Agulhas salt/heat leakage that led to an abrupt resumption of the Atlantic Meridional Ocean Circulation eventually triggering the Heinrich/Chinese Stadial 4 termination.
Interhemispheric anti-phasing of rainfall during the last glacial period
Publisher: Elsevier BV
Date: 12-2006
High-Latitude Forcing of the South American Summer Monsoon During the Last Glacial
Publisher: American Association for the Advancement of Science (AAAS)
Date: 03-02-2012
Abstract: Dansgaard/Oeschger (D/O) events—the sudden, millennial-scale periods of warmth that punctuate the cold climate of the Last Glacial period, and Heinrich events—cold intervals characterized by tremendous discharges of icebergs into the North Atlantic, have been observed at many locations in the Northern Hemisphere but not extensively in the Southern Hemisphere. Kanner et al. (p. 570 , published online 12 January see the Perspective by Rodbell ) present a stable isotope record from the central Peruvian Andes, which represents a record of the South American Summer Monsoon from 50,000 to 16,000 years ago and which contains the signals of D/O and Heinrich events. The Southern Hemisphere monsoon displayed an antiphase relationship to Northern Hemisphere monsoon intensity at the millennial scale, and Antarctic millennial-scale climate fluctuations influenced the South American Summer Monsoon.
Composition and sources of lipid compounds in speleothem calcite from southwestern Oregon and their paleoenvironmental implications
Publisher: Springer Science and Business Media LLC
Date: 07-2010
Multiple proxy analyses of a U/Th-dated stalagmite to reconstruct paleoenvironmental changes in northwestern Madagascar between 370 CE and 1300 CE
Publisher: Elsevier BV
Date: 03-2017
230Th and 231Pa in the Arctic Ocean: implications for particle fluxes and basin-scale Th/Pa fractionation
Publisher: Elsevier BV
Date: 10-2004
Assessing the dead carbon proportion of a modern speleothem from central Brazil
Publisher: Elsevier BV
Date: 06-2019
NALPS: a precisely dated European climate record 120–60 ka
Publisher: Copernicus GmbH
Date: 24-11-2011
Abstract: Abstract. Accurate and precise chronologies are essential in understanding the rapid and recurrent climate variations of the Last Glacial – known as Dansgaard-Oeschger (D-O) events – found in the Greenland ice cores and other climate archives. The existing chronological uncertainties during the Last Glacial, however, are still large. Radiometric age data and stable isotopic signals from speleothems are promising to improve the absolute chronology. We present a record of several precisely dated stalagmites from caves located at the northern rim of the Alps (NALPS), a region that favours comparison with the climate in Greenland. The record covers most of the interval from 120 to 60 ka at an average temporal resolution of 2 to 22 yr and 2σ-age uncertainties of ca. 200 to 500 yr. The rapid and large oxygen isotope shifts of 1 to 4.5‰ occurred within decades to centuries and strongly mimic the Greenland D-O pattern. Compared to the updated Greenland ice-core timescale (GICC05modelext) the NALPS record confirms the timing of rapid warming and cooling transitions between 118 and 106 ka, but suggests younger ages for D-O events between 106 and 60 ka. As an exception, the timing of the rapid transitions into and out of the stadial following GI 22 is earlier in NALPS than in the Greenland ice-core timescale. In addition, there is a discrepancy in the duration of this stadial between the ice-core and the stalagmite chronology (ca. 2900 vs. 3650 yr). The short-lived D-O events 18 and 18.1 are not recorded in NALPS, provoking questions with regard to the nature and the regional expression of these events. NALPS resolves recurrent short-lived climate changes within the cold Greenland stadial and warm interstadial successions, i.e. abrupt warming events preceding GI 21 and 23 (precursor-type events) and at the end of GI 21 and 25 (rebound-type events), as well as intermittent cooling events during GI 22 and 24. Such superimposed events have not yet been documented outside Greenland.
Zircon U-Pb geochronology, Hf isotopes and geochemistry of intrusive rocks in the Simorgh prospecting area, Lut Block, eastern Iran: petrogenesis and geological implications
Publisher: Springer Science and Business Media LLC
Date: 19-04-2018
Collapse of the Liangzhu and other Neolithic cultures in the lower Yangtze region in response to climate change
Publisher: American Association for the Advancement of Science (AAAS)
Date: 26-11-2021
Abstract: Floods and megadroughts affected the Neolithic cultures in the Yangtze River Delta between 4300 and 4000 years ago.
Interpretation of orbital scale variability in mid-latitude speleothem δ18O: Significance of growth rate controlled kinetic fractionation effects
Publisher: Elsevier BV
Date: 11-2015
Age and significance of the Quaternary cemented deposits of the Duje Valley (Picos de Europa, Northern Spain)
Publisher: Cambridge University Press (CUP)
Date: 2013
DOI: 10.1016/J.YQRES.2012.10.005
Abstract: Cemented calcareous breccias appear in the Picos de Europa (Cantabrian Mountains, Spain) resting on glacially abraded surfaces and covered by moraines. U/Th dating of the calcite coating the clasts was successful in two s les, the oldest one indicating that the breccias accumulated during or prior to Marine Isotope Stage (MIS) 11, and the youngest indicating later cementation during MIS 8. The former introduces a limit for the age of the glaciation preceding the breccias, which cannot correspond to an event younger than MIS 12. This is the oldest absolute age so far obtained for intercalated glacial/interglacial deposits of the Iberian Peninsula.
Future Earth and Sustainable Developments
Publisher: Elsevier BV
Date: 11-2020
Timing and nature of the penultimate deglaciation in a high alpine stalagmite from Switzerland
Publisher: Elsevier BV
Date: 10-2015
Early Neanderthal constructions deep in Bruniquel Cave in southwestern France
Publisher: Springer Science and Business Media LLC
Date: 25-05-2016
DOI: 10.1038/NATURE18291
Abstract: Very little is known about Neanderthal cultures, particularly early ones. Other than lithic implements and exceptional bone tools, very few artefacts have been preserved. While those that do remain include red and black pigments and burial sites, these indications of modernity are extremely sparse and few have been precisely dated, thus greatly limiting our knowledge of these predecessors of modern humans. Here we report the dating of annular constructions made of broken stalagmites found deep in Bruniquel Cave in southwest France. The regular geometry of the stalagmite circles, the arrangement of broken stalagmites and several traces of fire demonstrate the anthropogenic origin of these constructions. Uranium-series dating of stalagmite regrowths on the structures and on burnt bone, combined with the dating of stalagmite tips in the structures, give a reliable and replicated age of 176.5 thousand years (±2.1 thousand years), making these edifices among the oldest known well-dated constructions made by humans. Their presence at 336 metres from the entrance of the cave indicates that humans from this period had already mastered the underground environment, which can be considered a major step in human modernity.
Past Millennium Contrasting Hydroclimate Patterns Between Monsoonal Northern China and Arid Central Asia: a Modeling Study
Publisher: Springer Science and Business Media LLC
Date: 08-2018
Interseismic deformation above the Sunda Megathrust recorded in coral microatolls of the Mentawai islands, West Sumatra
Publisher: American Geophysical Union (AGU)
Date: 02-2007
DOI: 10.1029/2006JB004450
A multiple-proxy stalagmite record reveals historical deforestation in central Shandong, northern China
Publisher: Springer Science and Business Media LLC
Date: 13-08-2020
An exceptionally strengthened East Asian summer monsoon event between 19.9 and 17.1 ka BP recorded in a Hulu stalagmite
Publisher: Springer Science and Business Media LLC
Date: 03-2009
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