Mid-to Late Holocene East Antarctic ice-core tephrochronology: Implications for reconstructing volcanic eruptions and assessing their climatic impacts over the last 5,500 years

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  • Peter M. Abbott
  • Joseph R. McConnell
  • Nathan J. Chellman
  • Sepp Kipfstuhl
  • Maria Hörhold
  • Johannes Freitag
  • Cook, Eliza
  • William Hutchison
  • Michael Sigl
Ice cores are powerful archives for reconstructing volcanism as they contain both soluble (i.e. aerosols) and insoluble (i.e. tephra) products of volcanic eruptions and for more recent periods have high-precision annually resolved chronologies. The identification and geochemical analysis of cryptotephra in these cores can provide their volcanic source and latitude of injection, complementing records of sulphur injections from volcanic eruptions developed using continuous flow ice-core analysis. Here, we aim to improve the volcanic record for the Southern Hemisphere using a sampling strategy for cryptotephra identification based on coeval deposition of sulphate and microparticles in ice cores from the interior of East Antarctica covering the Mid-to Late Holocene. In total, 15 cryptotephras and one visible horizon were identified and geochemically characterised. Through comparisons to proximal deposits a range of possible sources were isolated for these horizons including the South Sandwich Islands, South Shetland Islands, Victoria Land (Antarctica) and South America. This new tephra framework contributes to the volcanic history of the region by extending the known geographical range of tephra deposition for previously identified events and providing a potential indication of phases of eruptive activity from key sources. Using the tephra-based source attributions and comparison of the timing of the events to a database of sulphur injections from Holocene volcanic eruptions it is possible to refine injection latitudes for some events, which can lead to improved estimates of their radiative forcing potential. The relatively low magnitude of the volcanic stratospheric sulphur injections related to the events in the tephra framework indicates they would have had a limited impact on Southern Hemisphere climate. Further work is required to improve source attributions for some events and/or to determine the magnitude of sulphur injections for individual events during years when coeval eruptions occurred. One limitation of the framework is the dominance of cryptotephra from regional volcanic sources and a lack of tephra from tropical sources, which hampers the refinement of eruption parameters for these large magnitude and often climate-impacting eruptions. This issue could be explored further through increased sampling of these events and/or development of additional analytical techniques for the identification and robust geochemical analysis of glass tephra shards less than 5 μm in diameter. Such investigations could be coupled with model experiments to determine the likelihood that past tropical eruptions deposited glass tephra shards over Antarctica and the potential size range and geographical spread of deposition.
OriginalsprogEngelsk
Artikelnummer108544
TidsskriftQuaternary Science Reviews
Vol/bind329
Antal sider20
ISSN0277-3791
DOI
StatusUdgivet - 2024

Bibliografisk note

Funding Information:
PA and MS received funding from the European Research Council under the European Union's Horizon 2020 research and innovation programme (grant agreement no. 820047 ). WH is funded by a UKRI Future Leaders Fellowship (MR/S033505/1). Continuous analysis of the B53 and B54 cores for sulphur and insoluble particles was supported by internal funding from the Desert Research Institute , with partial support for interpretation provided by National Science Foundation grant 1925417 to JRM. We thank the German field team for collecting the cores, as well as students and staff in the DRI ice-core group for assistance in the laboratory. Thanks to Pierre Lanari, Coralie Vesin and Hugo Dominguez Carranza for assistance with EPMA analysis at the University of Bern. Thanks to Gill Plunkett for comments on the manuscript. We thank two anonymous reviewers for their comments on the manuscript. This research benefitted from the participation of some of the authors in the Volcanic Impacts on Climate and Society (VICS) working group of the Past Global Changes (PAGES) project.

Funding Information:
PA and MS received funding from the European Research Council under the European Union's Horizon 2020 research and innovation programme (grant agreement no. 820047). WH is funded by a UKRI Future Leaders Fellowship (MR/S033505/1). Continuous analysis of the B53 and B54 cores for sulphur and insoluble particles was supported by internal funding from the Desert Research Institute, with partial support for interpretation provided by National Science Foundation grant 1925417 to JRM. We thank the German field team for collecting the cores, as well as students and staff in the DRI ice-core group for assistance in the laboratory. Thanks to Pierre Lanari, Coralie Vesin and Hugo Dominguez Carranza for assistance with EPMA analysis at the University of Bern. Thanks to Gill Plunkett for comments on the manuscript. We thank two anonymous reviewers for their comments on the manuscript. This research benefitted from the participation of some of the authors in the Volcanic Impacts on Climate and Society (VICS) working group of the Past Global Changes (PAGES) project.

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© 2024 The Authors

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