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Title: Sensitivity of the West Antarctic Ice Sheet to +2 °C (SWAIS 2C)
Abstract. The West Antarctic Ice Sheet (WAIS) presently holds enough ice to raise global sea level by 4.3 m if completely melted. The unknownresponse of the WAIS to future warming remains a significant challenge fornumerical models in quantifying predictions of future sea level rise. Sealevel rise is one of the clearest planet-wide signals of human-inducedclimate change. The Sensitivity of the West Antarctic Ice Sheet to a Warmingof 2 ∘C (SWAIS 2C) Project aims to understand past and currentdrivers and thresholds of WAIS dynamics to improve projections of the rateand size of ice sheet changes under a range of elevated greenhouse gaslevels in the atmosphere as well as the associated average globaltemperature scenarios to and beyond the +2 ∘C target of theParis Climate Agreement. Despite efforts through previous land and ship-based drilling on and alongthe Antarctic margin, unequivocal evidence of major WAIS retreat or collapse and its causes has remained elusive. To evaluate and plan for theinterdisciplinary scientific opportunities and engineering challenges thatan International Continental Drilling Program (ICDP) project along the Siple coast near the grounding zone of the WAIS could offer (Fig. 1), researchers, engineers, and logistics providers representing 10 countries held a virtualworkshop in October 2020. This international partnership comprised ofgeologists, glaciologists, oceanographers, geophysicists, microbiologists,climate and ice sheet modelers, and engineers outlined specific researchobjectives and logistical challenges associated with the recovery of Neogene and Quaternary geological records from the West Antarctic interior adjacent to the Kamb Ice Stream and at Crary Ice Rise. New geophysical surveys at these locations have identified drilling targets in which new drilling technologies will allow for the recovery of up to 200 m of sediments beneaththe ice sheet. Sub-ice-shelf records have so far proven difficult to obtainbut are critical to better constrain marine ice sheet sensitivity to pastand future increases in global mean surface temperature up to 2 ∘Cabove pre-industrial levels. Thus, the scientific and technological advances developed through this program will enable us to test whether WAIS collapsed during past intervals of warmth and determine its sensitivity to a +2 ∘C global warming threshold (UNFCCC, 2015).  more » « less
Award ID(s):
2034990
PAR ID:
10335831
Author(s) / Creator(s):
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; more » ; ; ; ; ; ; ; ; « less
Date Published:
Journal Name:
Scientific Drilling
Volume:
30
ISSN:
1816-3459
Page Range / eLocation ID:
101 to 112
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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The drill sites on the continental rise were in the path of numerous icebergs of various sizes that frequently forced us to pause drilling or leave the hole entirely as they approached the ship. The overall downtime caused by approaching icebergs was 50% of our time spent on site. 3. A medical evacuation cut the expedition short by 1 week. Recovery of core on the continental rise at Sites U1532 and U1533 cannot be used to indicate the extent of grounded ice on the shelf or, thus, of its retreat directly. However, the sediments contained in these cores offer a range of clues about past WAIS extent and retreat. At Sites U1532 and U1533, coarse-grained sediments interpreted to be ice-rafted debris (IRD) were identified throughout all recovered time periods. 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