Paleorecords of Antarctic ice motion, subglacial hydrology, and chemical weathering
With more than 70m of sea level equivalent ice stored in the polar ice sheets, sea level forecasting is heavily reliant on projections of ice sheet response to changes in global climate. One way that Earth scientists have approached this problem is to look back at past warm periods to determine how...
Main Author: | |
---|---|
Other Authors: | |
Format: | Thesis |
Language: | English |
Published: |
eScholarship, University of California
2023
|
Subjects: | |
Online Access: | https://escholarship.org/uc/item/54f6c8rt |
id |
ftcdlib:oai:escholarship.org:ark:/13030/qt54f6c8rt |
---|---|
record_format |
openpolar |
spelling |
ftcdlib:oai:escholarship.org:ark:/13030/qt54f6c8rt 2023-10-09T21:46:20+02:00 Paleorecords of Antarctic ice motion, subglacial hydrology, and chemical weathering Piccione, Gavin Gerard Blackburn, Terrence J 2023-01-01 https://escholarship.org/uc/item/54f6c8rt en eng eScholarship, University of California qt54f6c8rt https://escholarship.org/uc/item/54f6c8rt CC-BY Geology Geochemistry Paleoclimate science Antarctica Paleoclimatology U-Series Geochronology etd 2023 ftcdlib 2023-09-18T18:02:50Z With more than 70m of sea level equivalent ice stored in the polar ice sheets, sea level forecasting is heavily reliant on projections of ice sheet response to changes in global climate. One way that Earth scientists have approached this problem is to look back at past warm periods to determine how terrestrial ice mass changed in during previous climatic events. In Antarctic, however, there is an added complexity that 97.6% of the modern continent is covered by ice, which restricts access to the geologic record. Without terrestrial archives of Antarctic ice sheet evolution, it is challenging to parameterize the dominant processes that govern ice sheet sensitivity to climate and the environmental effects of ice loss. In this dissertation, I applied geochronologic, isotopic, elemental, and spectroscopic analyses to Antarctic subglacial chemical precipitates – a novel terrestrial record of basal conditions – to investigate the processes that link climate change, Antarctic ice motion, and the hydrologic system at the ice-bed interface. Collectively, this work expands our understanding of Antarctic evolution on centennial to millennial timescales and establishes Antarctic subglacial precipitates as climate archives analogous to speleothems.The first two chapters investigate the physical processes associated with subglacial hydrology and ice motion. By applying geochronologic and geochemical analyses to a group of precipitates that formed over tens-of-thousands of years during the Late Pleistocene, we showed that the continent-wide Antarctic subglacial hydrologic system responds rapidly (within 60 yrs.) to millennial-scale climate events, with more intense subglacial flushing during warm periods and diminished basal meltwater flow during cold periods. This close coupling between climate and subglacial hydrologic activity requires changes to Antarctic ice surface slope caused by hundreds of meters of thinning at the ice sheet margins. These studies provide evidence that the Antarctic gains and loses ice during ... Thesis Antarc* Antarctic Antarctica Ice Sheet University of California: eScholarship Antarctic The Antarctic |
institution |
Open Polar |
collection |
University of California: eScholarship |
op_collection_id |
ftcdlib |
language |
English |
topic |
Geology Geochemistry Paleoclimate science Antarctica Paleoclimatology U-Series Geochronology |
spellingShingle |
Geology Geochemistry Paleoclimate science Antarctica Paleoclimatology U-Series Geochronology Piccione, Gavin Gerard Paleorecords of Antarctic ice motion, subglacial hydrology, and chemical weathering |
topic_facet |
Geology Geochemistry Paleoclimate science Antarctica Paleoclimatology U-Series Geochronology |
description |
With more than 70m of sea level equivalent ice stored in the polar ice sheets, sea level forecasting is heavily reliant on projections of ice sheet response to changes in global climate. One way that Earth scientists have approached this problem is to look back at past warm periods to determine how terrestrial ice mass changed in during previous climatic events. In Antarctic, however, there is an added complexity that 97.6% of the modern continent is covered by ice, which restricts access to the geologic record. Without terrestrial archives of Antarctic ice sheet evolution, it is challenging to parameterize the dominant processes that govern ice sheet sensitivity to climate and the environmental effects of ice loss. In this dissertation, I applied geochronologic, isotopic, elemental, and spectroscopic analyses to Antarctic subglacial chemical precipitates – a novel terrestrial record of basal conditions – to investigate the processes that link climate change, Antarctic ice motion, and the hydrologic system at the ice-bed interface. Collectively, this work expands our understanding of Antarctic evolution on centennial to millennial timescales and establishes Antarctic subglacial precipitates as climate archives analogous to speleothems.The first two chapters investigate the physical processes associated with subglacial hydrology and ice motion. By applying geochronologic and geochemical analyses to a group of precipitates that formed over tens-of-thousands of years during the Late Pleistocene, we showed that the continent-wide Antarctic subglacial hydrologic system responds rapidly (within 60 yrs.) to millennial-scale climate events, with more intense subglacial flushing during warm periods and diminished basal meltwater flow during cold periods. This close coupling between climate and subglacial hydrologic activity requires changes to Antarctic ice surface slope caused by hundreds of meters of thinning at the ice sheet margins. These studies provide evidence that the Antarctic gains and loses ice during ... |
author2 |
Blackburn, Terrence J |
format |
Thesis |
author |
Piccione, Gavin Gerard |
author_facet |
Piccione, Gavin Gerard |
author_sort |
Piccione, Gavin Gerard |
title |
Paleorecords of Antarctic ice motion, subglacial hydrology, and chemical weathering |
title_short |
Paleorecords of Antarctic ice motion, subglacial hydrology, and chemical weathering |
title_full |
Paleorecords of Antarctic ice motion, subglacial hydrology, and chemical weathering |
title_fullStr |
Paleorecords of Antarctic ice motion, subglacial hydrology, and chemical weathering |
title_full_unstemmed |
Paleorecords of Antarctic ice motion, subglacial hydrology, and chemical weathering |
title_sort |
paleorecords of antarctic ice motion, subglacial hydrology, and chemical weathering |
publisher |
eScholarship, University of California |
publishDate |
2023 |
url |
https://escholarship.org/uc/item/54f6c8rt |
geographic |
Antarctic The Antarctic |
geographic_facet |
Antarctic The Antarctic |
genre |
Antarc* Antarctic Antarctica Ice Sheet |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet |
op_relation |
qt54f6c8rt https://escholarship.org/uc/item/54f6c8rt |
op_rights |
CC-BY |
_version_ |
1779322018229911552 |