scholarly journals Gravity Data Reveal Unexpected Antarctic Ice Variations

Eos ◽  
2020 ◽  
Vol 101 ◽  
Author(s):  
Stephanie Melchor
Keyword(s):  
Gravity Data ◽  
Ice Sheet ◽  
Antarctic Ice Sheet ◽  
Sea Levels ◽  
East Antarctic Ice Sheet

A new analysis of long-term satellite records shows the East Antarctic Ice Sheet is unexpectedly dependent on fluctuations in weather. This study may improve models of how much sea levels will rise.

scholarly journals A new sea-level record for the Neogene/Quaternary boundary reveals transition to a more stable East Antarctic Ice Sheet

2020 ◽  
Vol 117 (49) ◽  
pp. 30980-30987
Author(s):  
Kim A. Jakob ◽  
Paul A. Wilson ◽  
Jörg Pross ◽  
Thomas H. G. Ezard ◽  
Jens Fiebig ◽  
...  
Keyword(s):  
Sea Level ◽  
Northern Hemisphere ◽  
Ice Sheets ◽  
Ice Sheet ◽  
Deep Ocean ◽  
Antarctic Ice Sheet ◽  
Sea Levels ◽  
Ice Volume ◽  
Warming World ◽  
East Antarctic Ice Sheet

Sea-level rise resulting from the instability of polar continental ice sheets represents a major socioeconomic hazard arising from anthropogenic warming, but the response of the largest component of Earth’s cryosphere, the East Antarctic Ice Sheet (EAIS), to global warming is poorly understood. Here we present a detailed record of North Atlantic deep-ocean temperature, global sea-level, and ice-volume change for ∼2.75 to 2.4 Ma ago, when atmospheric partial pressure of carbon dioxide (pCO2) ranged from present-day (>400 parts per million volume, ppmv) to preindustrial (<280 ppmv) values. Our data reveal clear glacial–interglacial cycles in global ice volume and sea level largely driven by the growth and decay of ice sheets in the Northern Hemisphere. Yet, sea-level values during Marine Isotope Stage (MIS) 101 (∼2.55 Ma) also signal substantial melting of the EAIS, and peak sea levels during MIS G7 (∼2.75 Ma) and, perhaps, MIS G1 (∼2.63 Ma) are also suggestive of EAIS instability. During the succeeding glacial–interglacial cycles (MIS 100 to 95), sea levels were distinctly lower than before, strongly suggesting a link between greater stability of the EAIS and increased land-ice volumes in the Northern Hemisphere. We propose that lower sea levels driven by ice-sheet growth in the Northern Hemisphere decreased EAIS susceptibility to ocean melting. Our findings have implications for future EAIS vulnerability to a rapidly warming world.

scholarly journals Limited Retreat of the Wilkes Basin Ice Sheet during the Last Interglacial.

2020 ◽  
Author(s):  
Johannes Sutter ◽  
Olaf Eisen ◽  
Martin Werner ◽  
Klaus Grosfeld ◽  
Thomas Kleiner ◽  
...  
Keyword(s):  
Sea Level ◽  
Ice Core ◽  
Ice Sheet ◽  
Last Interglacial ◽  
Antarctic Ice Sheet ◽  
Future Global Warming ◽  
Grounding Line ◽  
Ice Core Record ◽  
East Antarctic Ice Sheet

&lt;p&gt;The response of the marine sectors of the East Antarctic Ice Sheet to future global warming represents a major source of uncertainty in sea level projections. If greenhouse gas emissions continue unbridled, ice loss in these areas may contribute up to several meters to long-term global sea level rise. In East Antarctica, thinning of the ice cover of the George V and Sabrina Coast is currently taking place, and its destabilization in past warm climate periods has been implied. The extent of such past interglacial retreat episodes cannot yet be quantitatively derived from paleo proxy records alone. Ice sheet modelling constrained by paleo observations is therefore critical to assess the stability of the East Antarctic Ice Sheet during warmer climates. We propose that a runaway retreat during the Last Interglacial of the George V Coast grounding line into the Wilkes Subglacial Basin would either leave a clear imprint on the water isotope composition in the neighbouring Talos Dome ice-core record or prohibit the preservation of an ice core record from the Last Interglacial alltogether. We test this hypothesis using a dynamic ice sheet model and infer that the marine Wilkes Basin ice sheet remained stable throughout the Last Interglacial (130,000-120,000 years ago). Our analysis provides the first constraint on Last Interglacial East Antarctic grounding line stability by benchmarking ice sheet model simulations with ice core records. Our findings also imply that ambitious mitigation efforts keeping global temperature rise in check could safeguard this region from irreversible ice loss in the long term.&lt;/p&gt;

scholarly journals Initiation and long-term instability of the East Antarctic Ice Sheet

Nature ◽  
2017 ◽  
Vol 552 (7684) ◽  
pp. 225-229 ◽  
Author(s):  
Sean P. S. Gulick ◽  
Amelia E. Shevenell ◽  
Aleksandr Montelli ◽  
Rodrigo Fernandez ◽  
Catherine Smith ◽  
...  
Keyword(s):  
Ice Sheet ◽  
Antarctic Ice Sheet ◽  
East Antarctic Ice Sheet

scholarly journals Windblown Pliocene diatoms and East Antarctic Ice Sheet retreat

2016 ◽  
Vol 7 (1) ◽  
Author(s):  
Reed P. Scherer ◽  
Robert M. DeConto ◽  
David Pollard ◽  
Richard B. Alley
Keyword(s):  
Ice Sheet ◽  
Antarctic Ice Sheet ◽  
East Antarctic Ice Sheet

scholarly journals East Antarctic ice sheet stability recorded in a high-elevation ice-cored moraine

2017 ◽  
Vol 159 ◽  
pp. 88-102 ◽  
Author(s):  
Nicole A. Bader ◽  
Kathy J. Licht ◽  
Michael R. Kaplan ◽  
Christine Kassab ◽  
Gisela Winckler
Keyword(s):  
Ice Sheet ◽  
High Elevation ◽  
Antarctic Ice Sheet ◽  
East Antarctic Ice Sheet

scholarly journals Evidence for a dynamic East Antarctic ice sheet during the mid-Miocene climate transition

2017 ◽  
Vol 478 ◽  
pp. 1-13 ◽  
Author(s):  
Elizabeth L. Pierce ◽  
Tina van de Flierdt ◽  
Trevor Williams ◽  
Sidney R. Hemming ◽  
Carys P. Cook ◽  
...  
Keyword(s):  
Ice Sheet ◽  
Antarctic Ice Sheet ◽  
Climate Transition ◽  
East Antarctic Ice Sheet

Anatomy of a meltwater drainage system beneath the ancestral East Antarctic ice sheet

2017 ◽  
Vol 10 (9) ◽  
pp. 691-697 ◽  
Author(s):  
Lauren M. Simkins ◽  
John B. Anderson ◽  
Sarah L. Greenwood ◽  
Helge M. Gonnermann ◽  
Lindsay O. Prothro ◽  
...  
Keyword(s):  
Ice Sheet ◽  
Drainage System ◽  
Antarctic Ice Sheet ◽  
East Antarctic Ice Sheet
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