ORCID Profile
0000-0001-7499-603X
Current Organisations
The University of Auckland
,
Massey University - Manawatu Campus
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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.
Archaeology | Social and Cultural Anthropology | Archaeology of New Guinea and Pacific Islands (excl. New Zealand) | Volcanology
Conserving Pacific Peoples Heritage | Natural Hazards not elsewhere classified | Expanding Knowledge in History and Archaeology |
Publisher: Informa UK Limited
Date: 18-03-2020
Publisher: Elsevier BV
Date: 10-2018
Publisher: Geological Society of America
Date: 2008
DOI: 10.1130/G24186A.1
Publisher: CSIRO Publishing
Date: 2003
DOI: 10.1071/SR02126
Abstract: Phosphorus (P) fertilisers are an essential input for the economic production of legume-based pastures in New Zealand (NZ) and Australia, but they often contain some unwanted elements that can contaminate the soil, thereby creating potential risks to the health of grazing animal, food quality, and soil quality. Fluorine (F) and cadmium (Cd) are considered to be the elements of most concern. Incidences of F toxicity (from direct ingestion of fertiliser), and accumulation of Cd in offal products above the maximum permissible concentration (MPC) set by the food authorities, have been reported in NZ. Similarly, Cd concentrations in some food grains may exceed the newly proposed MPCs by the Australian and New Zealand Food Authority. Cadmium and F continue to accumulate in the topsoils of NZ and Australian pastures as a result of P fertiliser use. The mobility of both these elements in soils is low and is similar to that of P. Risk of ground water contamination from F and Cd applied to most NZ pastures is low. The plant uptake of these elements, especially F, is also low in most pastoral soils. Cadmium accumulates mainly in liver and kidney of grazing animals mostly through herbage ingestion, whereas F accumulates mainly in the bones of these animals, mostly through soil ingestion. Soil ingestion is highest during the wetter winter months and at high stocking rates. Models have been developed to assess the impact of fertiliser use on the potential risks associated with F and Cd accumulation in soils. Measures to control F and Cd accumulation in soils, plants, and grazing animals are presented and future research needs are identified.
Publisher: Springer Science and Business Media LLC
Date: 05-2015
Publisher: Geological Society of America
Date: 11-2012
DOI: 10.1130/G33277.1
Publisher: Elsevier BV
Date: 10-2014
Publisher: Springer Science and Business Media LLC
Date: 12-09-2012
Publisher: Elsevier BV
Date: 10-2014
Publisher: Wiley
Date: 20-01-2011
Publisher: Elsevier BV
Date: 12-2011
Publisher: Geological Society of America
Date: 19-09-2011
DOI: 10.1130/B30447.1
Publisher: Springer Science and Business Media LLC
Date: 31-03-2012
Publisher: Oxford University Press (OUP)
Date: 22-02-2012
Publisher: Oxford University Press (OUP)
Date: 21-02-2012
Publisher: Elsevier BV
Date: 03-2004
Publisher: Springer Science and Business Media LLC
Date: 28-12-2022
DOI: 10.1007/S00024-022-03215-5
Abstract: On January 15th, 2022, at approximately 4:47 pm local time (0347 UTC), several weeks of heightened activity at the Hunga volcano 65 km northwest of Tongatapu, culminated in an 11-h long violent eruption which generated a significant near-field tsunami. Although the Kingdom of Tonga lies astride a large and tsunamigenic subduction zone, it has relatively few records of significant tsunami. Assessment activities took place both remotely and locally. Between March and June 2022, a field team quantified tsunami runup and inundation on the main populated islands Tongatapu and Eua, along with several smaller islands to the north, including the Ha’apai Group. Peak tsunami heights were ~ 19 m in western Tongatapu, ~ 20 m on south-eastern Nomuka Iki island and ~ 20 m on southern Tofua, located ~ 65 km S and E and 90 km N from Hunga volcano, respectively. In western Tongatapu, the largest tsunami surge overtopped a 13–15 m-high ridge along the narrow Hihifo peninsula in several locations. Analysis of tide gauge records from Nukualofa (which lag western Tongatapu arrivals by ~ 18–20 min), suggest that initial tsunami surges were generated prior to the largest volcanic explosions at ~ 0415 UTC. Further waves were generated by ~ 0426 UTC explosions that were accompanied by air-pressure waves. Efforts to model this event are unable to reproduce the timing of the large tsunami wave that toppled a weather station and communication tower on a 13 m-high ridge on western Tongatapu after 0500 UTC. Smaller tsunami waves continued until ~ 0900, coincident with a second energetic phase of eruption, and noted by eyewitnesses on Tungua and Mango Islands. Despite an extreme level of destruction caused by this tsunami, the death toll was extraordinarily low (4 victims). Interviews with witnesses and analysis of videos posted on social media suggest that this can be attributed to the arrival of smaller ‘pre tsunami’ waves that prompted evacuations, heightened tsunami awareness due to tsunami activity and advisories on the day before, the absence of tourists and ongoing tsunami education efforts since the 2009 Niuatoputapu, Tonga tsunami. This event highlights an unexpectedly great hazard from volcanic tsunami worldwide, which in Tonga’s case overprints an already extreme level of tectonic tsunami hazard. Education and outreach efforts should continue to emphasize the ‘natural warning signs’ of strong ground shaking and unusual wave and current action, and the importance of self-evacuation from coastal areas of low-lying islands. The stories of survival from this event can be used as global best practice for personal survival strategies from future tsunami.
Publisher: Elsevier BV
Date: 04-2014
Publisher: Walter de Gruyter GmbH
Date: 2010
DOI: 10.2478/V10085-010-0013-8
Abstract: The Pannonian Basin (Central Europe) hosts numerous alkali basaltic volcanic fields in an area similar to 200 000 km2. These volcanic fields were formed in an approximate time span of 8 million years producing smallvolume volcanoes typically considered to be monogenetic. Polycyclic monogenetic volcanic complexes are also common in each field however. The original morphology of volcanic landforms, especially phreatomagmatic volcanoes, is commonly modified. by erosion, commonly aided by tectonic uplift. The phreatomagmatic volcanoes eroded to the level of their sub-surface architecture expose crater to conduit filling as well as diatreme facies of pyroclastic rock assemblages. Uncertainties due to the strong erosion influenced by tectonic uplifts, fast and broad climatic changes, vegetation cover variations, and rapidly changing fluvio-lacustrine events in the past 8 million years in the Pannonian Basin have created a need to reconstruct and visualise the paleoenvironment into which the monogenetic volcanoes erupted. Here phreatomagmatic volcanic fields of the Miocene to Pleistocene western Hungarian alkali basaltic province have been selected and compared with modern phreatomagmatic fields. It has been concluded that the Auckland Volcanic Field (AVF) in New Zealand could be viewed as a prime modern analogue for the western Hungarian phreatomagmatic fields by sharing similarities in their pyroclastic successions textures such as pyroclast morphology, type, juvenile particle ratio to accidental lithics. Beside the AVF two other, morphologically more modified volcanic fields (Pali Aike, Argentina and Jeju, Korea) show similar features to the western Hungarian ex les, highlighting issues such as preservation potential of pyroclastic successions of phreatomagmatic volcanoes.
Publisher: SAGE Publications
Date: 07-2007
Abstract: Andesite tephras have not been used in tephrostratigraphic studies to the same extent as rhyolitic units because they are seen as being chemically more complex than the latter. They are particularly difficult to `fingerprint' owing to apparent heterogeneity in glass analyses from single andesitic layers. Using case study tephras from two andesite volcanoes in New Zealand, Mts Taranaki and Ruapehu, glass chemical heterogeneity is shown to be due predominantly to (1) differing particle types generated during closed-and open-vent phases of single eruption sequences, resulting in a broad range of glass compositions, and (2) contaminated glass microprobe analyses by various proportions of microlite phase(s). A simple evaluation procedure using least-squares mixing calculations is presented to classify glass data sets for hybrid analyses and to estimate the proportions of the main contaminant microlite phase. By employing particle morphology studies as well as the glass-analysis evaluation procedure, variations in andesitic glass compositions can be significantly reduced. Hence this approach shows promise for enabling the use of some andesitic tephras for tephrostratigraphic correlation. This may facilitate the addition of a new degree of resolution in tephrostratigraphic records.
Publisher: Springer Science and Business Media LLC
Date: 27-04-2011
Publisher: Springer Science and Business Media LLC
Date: 07-06-2014
Publisher: Springer Science and Business Media LLC
Date: 27-04-2014
Publisher: Elsevier BV
Date: 07-2011
Publisher: Elsevier BV
Date: 10-2013
Publisher: Elsevier BV
Date: 10-2014
Publisher: Springer Science and Business Media LLC
Date: 2015
Publisher: Elsevier BV
Date: 04-2014
Publisher: American Geophysical Union (AGU)
Date: 10-2023
DOI: 10.1029/2023JB026729
Publisher: Elsevier BV
Date: 08-2008
Publisher: Informa UK Limited
Date: 02-05-2021
Publisher: Copernicus GmbH
Date: 15-05-2023
DOI: 10.5194/EGUSPHERE-EGU23-17221
Abstract: Submarine eruptions dominate volcanism on Earth, but the recent eruption of Hunga Tonga& #8211 Hunga Ha& #699 apai volcano in January 2022 was one of the most explosive eruptions ever recorded. Many large calderas collapse during eruptions and the resulting morphology provides unvaluable information for understanding the processes during highly unpredictable eruptions.Here we present a detailed analyses of the post-eruption morphology of the caldera of the Hunga Tonga& #8211 Hunga Ha& #699 apai submarine volcano. We use the first multibeam bathymetry of the caldera, acquired only 5 months after the eruption on the MV Pacific Horizon, in May 2022.The multibeam data shows landslides with 0.5-1 km wide scars, mainly on the southern rim, with the deposits extending to the central part of the caldera. However, the flat inner caldera suggests that most of the material was deposited simultaneously to the caldera drop following the eruption, on the order of 800 m. Sediment cores collected inside the caldera show repeated turbidity current sedimentation pointing to ongoing mass wasting, which could have potentially led to eventual breaching of the rim on the north and east side. Submarine ridges were preserved on these sites, separating the inner caldera and two erosional channels on the outer part, which point to the main debris transport paths during the eruption. More than 50 active gas plumes are observed on the eastern side, located following a straight W-E transect, and on the northern side, where the vents are covering the collapse walls close to the eastern Hunga Tonga& #8211 Hunga Ha& #699 apai island. The presence of these vents and their distribution related to the morphology of the caldera, indicate the most energetic parts of the volcano, which can potentially still be hazardous. Our morphological analyses provide new insights of transport and depositional processes following highly energetic submarine eruptions.
Publisher: Frontiers Media SA
Date: 22-06-2017
Publisher: Wiley
Date: 22-05-2023
DOI: 10.1111/BTP.13231
Abstract: Here, we investigate Mid‐ to Late‐Holocene vegetation changes in low‐lying coastal areas in Tonga and how changing sea levels and recurrent volcanic eruptions have influenced vegetation dynamics on four islands of the Tongan archipelago (South Pacific). To investigate past vegetation and environmental change at Ngofe Marsh (‘Uta Vava’u), we examined palynomorphs (pollen and spores), charcoal (fire), and sediment characteristics (volcanic activity) from a 6.7‐m‐long sediment core. Radiocarbon dating indicated the sediments were deposited over the last 7700 years. We integrated the Ngofe Marsh data with similar previously published data from Avai’o’vuna Sw on Pangaimotu Island, Lotofoa Sw on Foa Island, and Finemui Sw on Ha’afeva Island. Plant taxa were categorized as littoral, mangrove, rainforest, successional/ disturbance, and wetland groups, and linear models were used to examine relationships between vegetation, relative sea level change, and volcanic eruptions (tephra). We found that relative sea level change has impacted vegetation on three of the four islands investigated. Volcanic eruptions were not identified as a driver of vegetation change. Rainforest decline does not appear to be driven by sea level changes or volcanic eruptions. From all sites analyzed, vegetation at Finemui Sw was most sensitive to changes in relative sea level. While vegetation on low‐lying Pacific islands is sensitive to changing sea levels, island characteristics, such as area and elevation, are also likely to be important factors that mediate specific island responses to drivers of change.
Publisher: American Geophysical Union (AGU)
Date: 05-2018
DOI: 10.1029/2017JB015357
Publisher: Geological Society of America
Date: 26-08-2014
DOI: 10.1130/B31010.1
Publisher: Elsevier BV
Date: 2012
Publisher: Oxford University Press (OUP)
Date: 13-02-2014
Publisher: Oxford University Press (OUP)
Date: 06-2016
Publisher: Elsevier BV
Date: 12-2015
Publisher: Geological Society of America
Date: 19-10-2015
DOI: 10.1130/G37023C.1
Publisher: Elsevier BV
Date: 11-2008
Publisher: Springer Science and Business Media LLC
Date: 31-05-2015
Publisher: Elsevier BV
Date: 09-2012
Publisher: Geological Society of America
Date: 14-06-2011
DOI: 10.1130/B30367.1
Publisher: Elsevier BV
Date: 12-2011
Publisher: Springer Science and Business Media LLC
Date: 09-06-2011
Publisher: Elsevier BV
Date: 11-2006
Publisher: Mineralogical Society of America
Date: 12-2019
DOI: 10.2138/AM-2019-6963
Abstract: The generation of silica undersaturated phonolite from silica saturated trachytes is uncommon, as it implies the crossing of the thermal barrier and critical plane of silica undersaturation. Nevertheless, a co-genetic suite displaying compositional transition from benmoreite-trachyte to phonolite has been observed within the Al Shaatha pyroclastic sequence in the Harrat Rahat Volcanic Field (Kingdom of Saudi Arabia). We performed crystallization experiments on benmoreite and trachyte starting compositions to simulate the pressure-temperature-volatile conditions that generated the observed liquid line of descent. The experimental conditions were 200–500 MPa, 850–1150 °C, 0–10 wt% H2O, 0.0–0.5 wt% CO2, and NNO+2 oxygen buffer. The experimental mineral assemblage consists of clinopyroxene, feldspar, and titanomagnetite, as well as glass in variable proportions. The degree of crystallinity of hydrous runs is lower than that of anhydrous ones at analogous pressure and temperature conditions. Clinopyroxene crystallizes with compositions diopside-augite and augite-hedenbergite, respectively, at 500 and 200 MPa. The saturation of feldspar is primarily controlled by temperature and volatile content, with the more potassic composition equilibrating at low temperature (850–900 °C) and anhydrous (for benmoreite) or hydrous (for trachyte) conditions. At low pressure (200 MPa), temperatures below 850 °C, and anhydrous conditions, the degree of crystallization is extremely high (& %), and the residual glass obtained from trachyte experiments is characterized by peralkaline and sodic affinity. This finding is consistent with natural eruptive products containing interstitial phonolitic glass within an anorthoclase framework. The shift from trachyte to phonolite is therefore interpreted as the result of open system interaction between trachytic magma and intercumulus phonolitic melt, as well as of dissolution of anorthoclase from a crystal mush.
Publisher: Elsevier BV
Date: 03-2007
Publisher: Springer Science and Business Media LLC
Date: 03-04-2010
Publisher: Oxford University Press (OUP)
Date: 15-12-2011
Start Date: 2023
End Date: 2026
Funder: Marsden Fund
View Funded ActivityStart Date: 04-2020
End Date: 12-2024
Amount: $328,788.00
Funder: Australian Research Council
View Funded Activity