Duanne White

Can in-situ cosmogenic 14C be used to assess the influence of clast recycling on exposure dating of ice retreat in Antarctica?

Publisher: Elsevier BV

Date: 06-2011

DOI: 10.1016/J.QUAGEO.2011.03.004

Late Holocene temperature variability in Tasmania inferred from borehole temperature data

Publisher: Copernicus GmbH

Date: 02-06-2017

DOI: 10.5194/CP-13-559-2017

Abstract: Abstract. Thirty-six borehole temperature–depth profiles were analysed to reconstruct the ground surface temperature history (GSTH) of eastern Tasmania for the past 5 centuries. We used the singular value decomposition method to invert borehole temperatures to produce temperature histories. The quality of borehole data was classified as high or low based on model misfit. The quality of the borehole data was not dependent on topography or land use. Analysis reveals that three to five high-quality borehole temperature–depth profiles were adequate to reconstruct robust paleotemperature records from any area. Average GSTH reconstructed from Tasmanian boreholes shows temperature increases about 1.2 ± 0.2 °C during the past 5 centuries. Reconstructed temperatures were consistent with meteorological records and other proxy records from Tasmania during their period of overlap. Temperature changes were greatest around the north-east coast and decreased towards the centre of Tasmania. The extension of the East Australian Current (EAC) further south and its strengthening around the north-east coast of Tasmania over the past century was considered a prime driver of warmer temperatures observed in north-east Tasmania.

Retreat history of the East Antarctic Ice Sheet since the Last Glacial Maximum

Publisher: Elsevier BV

Date: 09-2014

DOI: 10.1016/J.QUASCIREV.2013.07.024

Beryllium isotope signatures of ice shelves and sub-ice shelf circulation

Publisher: Elsevier BV

Date: 2019

DOI: 10.1016/J.EPSL.2018.10.004

Exposure ages from mountain dipsticks in Mac. Robertson Land, East Antarctica, indicate little change in ice-sheet thickness since the Last Glacial Maximum

Publisher: Geological Society of America

Date: 2007

DOI: 10.1130/G23503A.1

Products and stability of phosphate reactions with lead under freeze-thaw cycling in simple systems

Publisher: Elsevier BV

Date: 12-2011

DOI: 10.1016/J.ENVPOL.2011.08.026

Abstract: Orthophosphate fixation of metal contaminated soils in environments that undergo freeze-thaw cycles is understudied. Freeze-thaw cycling potentially influences the reaction rate, mineral chemical stability and physical breakdown of particles during fixation. This study determines what products form when phosphate (triple superphosphate [Ca(H(2)PO(4))(2)] or sodium phosphate [Na(3)PO(4)]) reacts with lead (PbSO(4) or PbCl(2)) in simple chemical systems in vitro, and assesses potential changes in formation during freeze-thaw cycles. Systems were subjected to multiple freeze-thaw cycles from +10 °C to -20 °C and then analysed by X-ray diffractometry. Pyromorphite formed in all systems and was stable over multiple freeze-thaw cycles. Low temperature lead orthophosphate reaction efficiency varied according to both phosphate and lead source the most time-efficient pyromorphite formation was observed when PbSO(4) and Na(3)PO(4) were present together. These findings have implications for the manner in which metal contaminated materials in freezing ground can be treated with phosphate.

Geomorphology and glacial history of Rauer Group, East Antarctica

Publisher: Cambridge University Press (CUP)

Date: 07-2009

DOI: 10.1016/J.YQRES.2009.04.001

Abstract: The presence of glacial sediments across the Rauer Group indicates that the East Antarctic ice sheet formerly covered the entire archipelago and has since retreated at least 15 km from its maximum extent. The degree of weathering of these glacial sediments suggests that ice retreat from this maximum position occurred sometime during the latter half of the last glacial cycle. Following this phase of retreat, the ice sheet margin has not expanded more than ∼ 1 km seaward of its present position. This pattern of ice sheet change matches that recorded in Vestfold Hills, providing further evidence that the diminutive Marine Isotope Stage 2 ice sheet advance in the nearby Larsemann Hills may have been influenced by local factors rather than a regional ice-sheet response to climate and sea-level change.

Rapid ice sheet response to deglacial and Holocene paleoenvironmental changes in eastern Prydz Bay, East Antarctica

Publisher: Elsevier BV

Date: 03-2022

DOI: 10.1016/J.QUASCIREV.2022.107401

Unglaciated areas in East Antarctica during the Last Glacial (Marine Isotope Stage 3) – New evidence from Rauer Group

Publisher: Elsevier BV

Date: 12-2016

DOI: 10.1016/J.QUASCIREV.2016.08.021

Formation and stability of Pb-, Zn-& Cu-PO 4 phases at low temperatures: Implications for heavy metal fixation in polar environments

Publisher: Elsevier BV

Date: 02-2012

DOI: 10.1016/J.ENVPOL.2011.09.035

Abstract: Low temperatures and frequent soil freeze-thaw in polar environments present challenges for the immobilisation of metals. To address these challenges we investigated the chemical forms of Pb, Zn and Cu in an Antarctic landfill, examined in vitro reaction kinetics of these metals and orthophosphate at 2 and 22 °C for up to 185 days, and subjected the products to freeze-thaw. Reaction products at both temperatures were similar, but the rate of production varied, with Cu-PO(4) phases forming faster, and the Zn- and Pb-PO(4) phases slower at 2 °C. All metal-orthophosphate phases produced were stable during a 2.5 h freeze-thaw cycle to -30 °C. Metal immobilisation using orthophosphate can be successful in polar regions, but treatments will need to consider differing mineral stabilities and reaction rates at low temperatures.

Chapter 12 Antarctica at the Last Glacial Maximum, deglaciation and the Holocene

Publisher: Elsevier

Date: 2008

DOI: 10.1016/S1571-9197(08)00012-8

A review of the Australian-New Zealand sector of the Southern Ocean over the last 30ka (Aus-INTIMATE project)

Publisher: Elsevier BV

Date: 08-2013

DOI: 10.1016/J.QUASCIREV.2012.07.018

Genomewide SNP markers breathe new life into phylogeography and species delimitation for the problematic short‐necked turtles (Chelidae: Emydura) of eastern Australia

Publisher: Wiley

Date: 12-2018

DOI: 10.1111/MEC.14925

Abstract: Understanding the evolutionary history of ersifying lineages and the delineation of evolutionarily significant units and species remains major challenges for evolutionary biology. Low-cost representational s ling of the genome for single nucleotide polymorphisms shows great potential at the temporal scales that are typically the focus of species delimitation and phylogeography. We apply these markers to a case study of a freshwater turtle, Emydura macquarii, whose systematics has so far defied resolution, to bring to light a dynamic system of substantive allopatric lineages erging on independent evolutionary trajectories, but held back in the process of speciation by low level and episodic exchange of alleles across drainage ides on various timescales. In the context of low-level episodic gene flow, speciation is often reticulate, rather than a bifurcating process. We argue that species delimitation needs to take into account the pattern of ancestry and descent of erging lineages in allopatry together with the recent and contemporary processes of dispersal and gene flow that retard and obscure that ergence. Underpinned by a strong focus on lineage diagnosability, this combined approach provides a means for addressing the challenges of incompletely isolated populations with uncommon, but recurrent gene flow in studies of species delimitation, a situation likely to be frequently encountered. Taxonomic decisions in cases of allopatry often require subjective judgements. Our strategy, which adds an additional level of objectivity before that subjectivity is applied, reduces the risk of taxonomic inflation that can accompany lineage approaches to species delimitation.

Glaciology and geological signature of the Last Glacial Maximum Antarctic ice sheet

Publisher: Elsevier BV

Date: 10-2013

DOI: 10.1016/J.QUASCIREV.2013.08.011

Phylogeography and species delimitation of Cherax destructor (Decapoda: Parastacidae) using genome-wide SNPs

Publisher: CSIRO Publishing

Date: 2019

DOI: 10.1071/MF18347

Abstract: Cherax is a genus of 58 species of decapod crustaceans that are widespread across Australia and New Guinea. We use single-nucleotide polymorphisms (SNPs) to examine phylogeographic patterns in the most widespread species of Cherax, namely, C. destructor, and test the distinctiveness of one undescribed species, two C. destructor subspecies, previously proposed evolutionarily significant units, and management units. Both the phylogenetic analyses and the analysis of fixed allelic differences between populations support the current species-level taxonomy of C. setosus, C. depressus, C. dispar and C. destructor, the distinctiveness of C. destructor albidus and C. d. destructor and the existence of one undescribed species. The two populations of C. d. albidus from the Glenelg and Wimmera rivers were significantly distinct, with eight diagnostic differences (& % fixed differences, null expectation is four fixed differences), but this low level of ergence is interpreted as within the range that might be expected of management units, that is, among allopatric populations of a single species or subspecies. A southern clade of C. d. destructor comprising the Murray River and its tributaries upstream from its confluence with the Darling River is genetically distinct from a northern clade comprising populations from the Lake Eyre Basin, the northern half of the Murray–Darling Basin (Darling River catchment) and the Lower Murray River below the Darling confluence.

A community-based geological reconstruction of Antarctic Ice Sheet deglaciation since the Last Glacial Maximum

Publisher: Elsevier BV

Date: 09-2014

DOI: 10.1016/J.QUASCIREV.2014.06.025

Cosmogenic nuclide evidence for enhanced sensitivity of an East Antarctic ice stream to change during the last deglaciation

Publisher: Geological Society of America

Date: 03-12-2010

DOI: 10.1130/G31591.1

Reproductive ecology of a critically endangered alpine galaxiid

Publisher: Wiley

Date: 28-01-2021

DOI: 10.1111/JFB.14603

Age-related environmental gradients influence invertebrate distribution in the Prince Charles Mountains, East Antarctica

Publisher: The Royal Society

Date: 12-2016

DOI: 10.1098/RSOS.160296

Abstract: The potential impact of environmental change on terrestrial Antarctic ecosystems can be explored by inspecting bio ersity patterns across large-scale gradients. Unfortunately, morphology-based surveys of Antarctic invertebrates are time-consuming and limited by the cryptic nature of many taxa. We used bio ersity information derived from high-throughput sequencing (HTS) to elucidate the relationship between soil properties and invertebrate bio ersity in the Prince Charles Mountains, East Antarctica. Across 136 analysed soil s les collected from Mount Menzies, Mawson Escarpment and Lake Terrasovoje, we found invertebrate distribution in the Prince Charles Mountains significantly influenced by soil salinity and/or sulfur content. Phyla Tardigrada and Arachnida occurred predominantly in low-salinity substrates with abundant nutrients, whereas Bdelloidea (Rotifera) and Chromadorea (Nematoda) were more common in highly saline substrates. A significant correlation between invertebrate occurrence, soil salinity and time since deglaciation indicates that terrain age indirectly influences Antarctic terrestrial bio ersity, with more recently deglaciated areas supporting greater ersity. Our study demonstrates the value of HTS metabarcoding to investigate environmental constraints on inconspicuous soil bio ersity across large spatial scales.

Eastern Australian late Holocene paleotemperature variation inferred from borehole temperature data

Publisher: Elsevier BV

Date: 11-2018

DOI: 10.1016/J.GLOPLACHA.2018.09.001

Retreat of the East Antarctic ice sheet during the last glacial termination

Publisher: Springer Science and Business Media LLC

Date: 16-01-2011

DOI: 10.1038/NGEO1061

Effects of freeze-thaw cycling on metal-phosphate formation and stability in single and multi-metal systems

Publisher: Elsevier BV

Date: 04-2013

DOI: 10.1016/J.ENVPOL.2013.01.007

Abstract: Freeze-thaw cycling may influence the chemistry, mineral stability and reaction rate during metal orthophosphate fixation. This study assessed the formation and stability of Cu-, Pb-, and Zn-phosphates in chemically simple laboratory systems during 240 freeze-thaw cycles (120 days) from +10 to -20 °C, using X-ray diffractometry. In single heavy metal systems, chloro- and hydroxy-pyromorphite (Pb(5)(PO(4))(3)(Cl,OH)), sodalite (Na(6)Zn(6)(PO(4))(6)·8H(2)O), chiral zincophosphate (Na(12)(Zn(12)P(12)O(48))·12H(2)O), and copper phosphate hydrate (Cu(3)(PO(4))(2)·3H(2)O) were the primary phosphate minerals that formed, and were typically stable during the experiment. Zinc and Cu-phosphate formation was reduced in multi heavy metal systems, and was substantially lower in abundance than chloropyromorphite. Successful Cu-, Pb- and Zn-phosphate formation can be expected in cold and freezing environments like the polar regions. However, field implementation of orthophosphate fixation needs to consider competing ion effects, concentration of the phosphate source, and the amount of free-water.

Deglaciation and weathering of Larsemann Hills, East Antarctica

Publisher: Cambridge University Press (CUP)

Date: 03-06-2009

DOI: 10.1017/S0954102009002028

Linkage Projects - Grant ID: LP140100521

Start Date: 12-2014

End Date: 06-2018

Amount: $269,692.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE140100023

Start Date: 2014

End Date: 12-2014

Amount: $360,000.00

Funder: Australian Research Council

Special Research Initiatives - Grant ID: SR200100008

Start Date: 08-2021

End Date: 12-2027

Amount: $20,000,000.00

Funder: Australian Research Council