Where might we find evidence of a Last Interglacial West Antarctic Ice Sheet collapse in Antarctic ice core records?

West Antarctic ◽

Isotope Record ◽

Water Stable Isotope

The Last Interglacial period (130-115 ka BP, hereafter LIG) is often considered as a prime example to study the effect of warmer-than-present temperatures on polar ice sheets evolution. As the debate mainly focuses on the causes and tipping point of a potential collapse of the West Antarctic Ice Sheet (hereafter WAIS), few investigations examine the consequences of a wais collapse in terms of atmospheric circulation. However, a knowledge of the state of the atmosphere is necessary to use proxy data recorded in ice cores. By analysing a new ice core drilled in Skytrain ice rise and using climate modeling, the WACSWAIN (WArm Climate Stability of West Antarctic ice sheet in the last Interglacial) aims to reconstruct WAIS extent during the LIG. Here, we use simulations from the atmospheric general circulation model HadCM3 with different 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. 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.

Snow Accumulation Variability Over the West Antarctic Ice Sheet Since 1900: A Comparison of Ice Core Records With ERA‐20C Reanalysis

Geophysical Research Letters ◽

10.1002/2017gl075135 ◽

2017 ◽

Vol 44 (22) ◽

pp. 11,482-11,490 ◽

Cited By ~ 8

Author(s):

Yetang Wang ◽

Elizabeth R. Thomas ◽

Shugui Hou ◽

Baojuan Huai ◽

Shuangye Wu ◽

...

Keyword(s):

Ice Core ◽

Ice Sheet ◽

Snow Accumulation ◽

The West ◽

Antarctic Ice Sheet ◽

West Antarctic ◽

Ice Core Records

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

10.5194/egusphere-egu21-5504 ◽

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 ◽

Water Isotope

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).&#160; 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.&#160; 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.&#160; 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.&#160; Marine chemical content in the ice core could indicate variability in the proximity of the site to a marine environment.&#160; 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, &#948;18O and &#948;D increase from the last glacial maximum to the Holocene.&#160; &#948;18O and &#948;D increase and sodium and magnesium levels decline from deglaciation into the early Holocene. &#948;18O and &#948;D show an abrupt increase in the early Holocene at about 8,000 years before present.&#160; Sea salt similarly increases 2-fold and becomes more variable about 1,000 years later (7,000 years before present).&#160; These increases could indicate a retreat of the ice shelf to its current position.

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

10.5194/cp-2021-7-supplement ◽

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 ◽

Victoria Land ◽

Supplementary Material

Modelling the Antarctic Ice Sheet across the mid-Pleistocene transition – implications for Oldest Ice

The Cryosphere ◽

10.5194/tc-13-2023-2019 ◽

2019 ◽

Vol 13 (7) ◽

pp. 2023-2041 ◽

Cited By ~ 10

Author(s):

Johannes Sutter ◽

Hubertus Fischer ◽

Klaus Grosfeld ◽

Nanna B. Karlsson ◽

Thomas Kleiner ◽

...

Keyword(s):

Ice Core ◽

Ice Sheet ◽

Middle Pleistocene ◽

Climate Modelling ◽

Geothermal Heat ◽

Antarctic Ice Sheet ◽

Climate Conditions ◽

West Antarctic ◽

Pleistocene Climate

Abstract. The international endeavour to retrieve a continuous ice core, which spans the middle Pleistocene climate transition ca. 1.2–0.9 Myr ago, encompasses a multitude of field and model-based pre-site surveys. We expand on the current efforts to locate a suitable drilling site for the oldest Antarctic ice core by means of 3-D continental ice-sheet modelling. To this end, we present an ensemble of ice-sheet simulations spanning the last 2 Myr, employing transient boundary conditions derived from climate modelling and climate proxy records. We discuss the imprint of changing climate conditions, sea level and geothermal heat flux on the ice thickness, and basal conditions around previously identified sites with continuous records of old ice. Our modelling results show a range of configurational ice-sheet changes across the middle Pleistocene transition, suggesting a potential shift of the West Antarctic Ice Sheet to a marine-based configuration. Despite the middle Pleistocene climate reorganisation and associated ice-dynamic changes, we identify several regions conducive to conditions maintaining 1.5 Myr (million years) old ice, particularly around Dome Fuji, Dome C and Ridge B, which is in agreement with previous studies. This finding strengthens the notion that continuous records with such old ice do exist in previously identified regions, while we are also providing a dynamic continental ice-sheet context.

Atmospheric CO2over the last 1000 years: A high-resolution record from the West Antarctic Ice Sheet (WAIS) Divide ice core

Global Biogeochemical Cycles ◽

10.1029/2011gb004247 ◽

2012 ◽

Vol 26 (2) ◽

pp. n/a-n/a ◽

Cited By ~ 50

Author(s):

Jinho Ahn ◽

Edward J. Brook ◽

Logan Mitchell ◽

Julia Rosen ◽

Joseph R. McConnell ◽

...

Keyword(s):

High Resolution ◽

Ice Core ◽

Ice Sheet ◽

The West ◽

Antarctic Ice Sheet ◽

Interhemispheric coupling, the West Antarctic Ice Sheet and warm Antarctic interglacials

Climate of the Past ◽

10.5194/cp-6-431-2010 ◽

2010 ◽

Vol 6 (4) ◽

pp. 431-443 ◽

Cited By ~ 51

Author(s):

P. B. Holden ◽

N. R. Edwards ◽

E. W. Wolff ◽

N. J. Lang ◽

J. S. Singarayer ◽

...

Keyword(s):

Ice Core ◽

Ice Sheet ◽

Meridional Overturning Circulation ◽

Antarctic Ice Sheet ◽

West Antarctic ◽

Transient Simulations ◽

Series Of Experiments ◽

Atmospheric Co2 Concentrations ◽

The Impact

Abstract. Ice core evidence indicates that even though atmospheric CO2 concentrations did not exceed ~300 ppm at any point during the last 800 000 years, East Antarctica was at least ~3–4 °C warmer than preindustrial (CO2~280 ppm) in each of the last four interglacials. During the previous three interglacials, this anomalous warming was short lived (~3000 years) and apparently occurred before the completion of Northern Hemisphere deglaciation. Hereafter, we refer to these periods as "Warmer than Present Transients" (WPTs). We present a series of experiments to investigate the impact of deglacial meltwater on the Atlantic Meridional Overturning Circulation (AMOC) and Antarctic temperature. It is well known that a slowed AMOC would increase southern sea surface temperature (SST) through the bipolar seesaw and observational data suggests that the AMOC remained weak throughout the terminations preceding WPTs, strengthening rapidly at a time which coincides closely with peak Antarctic temperature. We present two 800 kyr transient simulations using the Intermediate Complexity model GENIE-1 which demonstrate that meltwater forcing generates transient southern warming that is consistent with the timing of WPTs, but is not sufficient (in this single parameterisation) to reproduce the magnitude of observed warmth. In order to investigate model and boundary condition uncertainty, we present three ensembles of transient GENIE-1 simulations across Termination II (135 000 to 124 000 BP) and three snapshot HadCM3 simulations at 130 000 BP. Only with consideration of the possible feedback of West Antarctic Ice Sheet (WAIS) retreat does it become possible to simulate the magnitude of observed warming.

Do blue-ice moraines in the Heritage Range show the West Antarctic ice sheet survived the last interglacial?

Palaeogeography Palaeoclimatology Palaeoecology ◽

10.1016/j.palaeo.2011.01.027 ◽

2012 ◽

Vol 335-336 ◽

pp. 61-70 ◽

Cited By ~ 29

Author(s):

Christopher J. Fogwill ◽

Andrew S. Hein ◽

Michael J. Bentley ◽

David E. Sugden

Keyword(s):

Ice Sheet ◽

Last Interglacial ◽

The West ◽

Antarctic Ice Sheet ◽

Ionic content in an ice core from the West Antarctic Ice Sheet: 1882-2008 A.D.

Brazilian Journal of Geology ◽

10.1590/2317-4889201820180037 ◽

2018 ◽

Vol 48 (4) ◽

pp. 853-865

Author(s):

Isaías Ullmann Thoen ◽

Jefferson Cardia Simões ◽

Filipe Gaudie Ley Lindau ◽

Sharon Buchanan Sneed

Keyword(s):

Ice Core ◽

Ice Sheet ◽

The West ◽

Antarctic Ice Sheet ◽

Ionic Content ◽

Environmental Constraints on West Antarctic Ice-Sheet Formation

Journal of Glaciology ◽

10.1017/s0022143000008947 ◽

1987 ◽

Vol 33 (115) ◽

pp. 346-356 ◽

Cited By ~ 5

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 ◽

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.