Supplementary material to "Enhanced Moisture Delivery into Victoria Land, East Antarctica During the Early Last Interglacial: Implications for West Antarctic Ice Sheet Stability"

2021 ◽  
Author(s):  
Yuzhen Yan ◽  
Nicole E. Spaulding ◽  
Michael L. Bender ◽  
Edward J. Brook ◽  
John A. Higgins ◽  
...  
Keyword(s):  
Ice Sheet ◽  
East Antarctica ◽  
Last Interglacial ◽  
Antarctic Ice Sheet ◽  
West Antarctic Ice Sheet ◽  
West Antarctic ◽  
Victoria Land ◽  
Supplementary Material

Inferring the Last Interglacial West Antarctic Ice Sheet from the coupling of an ice core water stable isotope record and an atmospheric general circulation model

2020 ◽  
Author(s):  
Sentia Goursaud ◽  
Louise Sime ◽  
Eric Wolff
Keyword(s):  
General Circulation ◽  
Ice Core ◽  
Ice Sheet ◽  
Circulation Model ◽  
Last Interglacial ◽  
Antarctic Ice Sheet ◽  
West Antarctic Ice Sheet ◽  
West Antarctic ◽  
Isotope Record ◽  
Water Stable Isotope

<p><span><span>The Last Interglacial period (</span></span><span><span>130-115 ka BP, </span></span><span><span>hereafter LIG</span></span><span><span>) </span></span><span><span>is often considered as a</span></span> <span><span>prime example to study the effect of </span></span><span><span>warmer-than-present </span></span><span><span>temperatures on polar ice sheets evolution. As the debate mainly focuses on the causes and tip</span></span><span><span>ping</span></span><span><span> point of a potential collapse of the West Antarctic Ice Sheet </span></span><span><span>(hereafter </span></span><span><span>WAIS</span></span><span><span>), </span></span><span><span>few investigations examine the consequences of a wais collapse in terms of atmospheric circulation. </span></span><span><span>However, a knowledge of </span></span><span><span>the state of the atmosphere is necessary to use proxy data recorded in ice cores. </span></span><span><span>By analysing a new ice core drilled in Skytrain ice rise and using climate modeling, t</span></span><span><span>he WACSWAIN (WArm Climate Stability of West Antarctic ice sheet in the last Interglacial) </span></span><span><span>aims to </span></span><span><span>reconstruct WAIS extent during the LIG. Here, we use simulations from the atmospheric general circulation model HadCM3 </span></span> <span><span>with </span></span><span><span>different </span></span><span><span>WAIS configurations. We show that changes in temperature are directly linked to changes in orography through thermodynamic effects, as well as a linear sea ice extent rise over the Pacific Ocean with the WAIS reduction explained by a reversal of meridional winds turning southwards as the WAIS disappears.</span></span> <span><span>At the Skytrain ice rise, we show that not only the isotopic thermometer can be applied, but we also suggest that the water stable isotope record imprinted in the ice core will allow us to quantify the wais reduction.</span></span></p>

scholarly journals Environmental Constraints on West Antarctic Ice-Sheet Formation

1987 ◽  
Vol 33 (115) ◽  
pp. 346-356 ◽  
Author(s):  
D.R. Lindstrom ◽  
D.R. MacAyeal
Keyword(s):  
Sea Level ◽  
Environmental Influence ◽  
Accumulation Rate ◽  
Ice Sheet ◽  
Interglacial Period ◽  
Last Interglacial ◽  
The West ◽  
Antarctic Ice Sheet ◽  
West Antarctic Ice Sheet ◽  
West Antarctic

AbstractSmall perturbations in Antarctic environ-mental conditions can culminate in the demise of the Antarctic ice sheet’s western sector. This may have happened during the last interglacial period, and could recur within the next millennium due to atmospheric warming from trace gas and CO2increases. In this study, we investigate the importance of sea-level, accumulation rate, and ice influx from the East Antarctic ice sheet in the re-establishment of the West Antarctic ice sheet from a thin cover using a time-dependent numerical ice-shelf model. Our results show that a precursor to the West Antarctic ice sheet can form within 3000 years. Sea-level lowering caused by ice-sheet development in the Northern Hemisphere has the greatest environmental influence. Under favorable conditions, ice grounding occurs over all parts of the West Antarctic ice sheet except up-stream of Thwaites Glacier and in the Ross Sea region.

scholarly journals Environmental Constraints on West Antarctic Ice-Sheet Formation

1987 ◽  
Vol 33 (115) ◽  
pp. 346-356 ◽  
Author(s):  
D.R. Lindstrom ◽  
D.R. MacAyeal
Keyword(s):  
Sea Level ◽  
Environmental Influence ◽  
Accumulation Rate ◽  
Ice Sheet ◽  
Interglacial Period ◽  
Last Interglacial ◽  
The West ◽  
Antarctic Ice Sheet ◽  
West Antarctic Ice Sheet ◽  
West Antarctic

AbstractSmall perturbations in Antarctic environ-mental conditions can culminate in the demise of the Antarctic ice sheet’s western sector. This may have happened during the last interglacial period, and could recur within the next millennium due to atmospheric warming from trace gas and CO2increases. In this study, we investigate the importance of sea-level, accumulation rate, and ice influx from the East Antarctic ice sheet in the re-establishment of the West Antarctic ice sheet from a thin cover using a time-dependent numerical ice-shelf model. Our results show that a precursor to the West Antarctic ice sheet can form within 3000 years. Sea-level lowering caused by ice-sheet development in the Northern Hemisphere has the greatest environmental influence. Under favorable conditions, ice grounding occurs over all parts of the West Antarctic ice sheet except up-stream of Thwaites Glacier and in the Ross Sea region.

WACSWAIN project: isotope and chemical ice core records from Skytrain Ice Rise, Antarctica

2021 ◽  
Author(s):  
Mackenzie Grieman ◽  
Helene Hoffmann ◽  
Jack Humby ◽  
Robert Mulvaney ◽  
Christoph Nehrbass-Ahles ◽  
...  
Keyword(s):  
Ice Core ◽  
Ice Sheet ◽  
Before Present ◽  
Last Interglacial ◽  
Ice Shelf ◽  
The West ◽  
Antarctic Ice Sheet ◽  
West Antarctic Ice Sheet ◽  
West Antarctic ◽  
Water Isotope

<p>The aim of the WArm Climate Stability of the West Antarctic ice sheet in the last INterglacial (WACSWAIN) project is to investigate the possible collapse of the West Antarctic Ice Sheet (WAIS) and its surrounding ice shelves during the Last Interglacial (~120,000 years ago).  As part of this project, a 651-meter ice core was drilled to bedrock at Skytrain Ice Rise in Antarctica during the 2018/2019 field season.  Ions and elements originating from marine sources along with water isotope content in this ice core can be used to infer changes in ice sheet and ice shelf extent.  The stable water isotope signal has the potential to capture both regional climate change and changes in the elevation of the drilling site through time.  Marine chemical content in the ice core could indicate variability in the proximity of the site to a marine environment.  Water isotopes and chemical impurities in the ice core were analysed continuously using cavity ring down spectroscopy and inductively coupled plasma mass spectrometry, respectively. As expected, δ<sup>18</sup>O and δD increase from the last glacial maximum to the Holocene.  δ<sup>18</sup>O and δD increase and sodium and magnesium levels decline from deglaciation into the early Holocene. δ<sup>18</sup>O and δD show an abrupt increase in the early Holocene at about 8,000 years before present.  Sea salt similarly increases 2-fold and becomes more variable about 1,000 years later (7,000 years before present).  These increases could indicate a retreat of the ice shelf to its current position.</p>

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