Abstract. Cosmogenic-nuclide concentrations in subglacial bedrock cores show that the West Antarctic Ice Sheet (WAIS) at a site between Thwaites and Pope glaciers was at least 35 m thinner than present in the past several thousand years and then subsequently thickened. This is important because of concern that present thinning and grounding line retreat at these and nearby glaciers in the Amundsen Sea Embayment may irreversibly lead to deglaciation of significant portions of the WAIS, with decimeter- to meter-scale sea level rise within decades to centuries. A past episode of ice sheet thinning that took place in a similar, although not identical, climate was not irreversible. We propose that the past thinning–thickening cycle was due to a glacioisostatic rebound feedback, similar to that invoked as a possible stabilizing mechanism for current grounding line retreat, in which isostatic uplift caused by Early Holocene thinning led to relative sea level fall favoring grounding line advance.
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Reversible ice sheet thinning in the Amundsen Sea Embayment during the Late Holocene
Cosmogenic-nuclide concentrations in subglacial
bedrock cores show that theWest Antarctic Ice Sheet (WAIS)
at a site between Thwaites and Pope glaciers was at least
35m thinner than present in the past several thousand years
and then subsequently thickened. This is important because
of concern that present thinning and grounding line retreat at
these and nearby glaciers in the Amundsen Sea Embayment
may irreversibly lead to deglaciation of significant portions
of the WAIS, with decimeter- to meter-scale sea level rise
within decades to centuries. A past episode of ice sheet thinning
that took place in a similar, although not identical, climate
was not irreversible.We propose that the past thinning–
thickening cycle was due to a glacioisostatic rebound feedback,
similar to that invoked as a possible stabilizing mechanism
for current grounding line retreat, in which isostatic
uplift caused by Early Holocene thinning led to relative sea
level fall favoring grounding line advance.
more »
« less
- Award ID(s):
- 2317097
- NSF-PAR ID:
- 10499412
- Publisher / Repository:
- EGU
- Date Published:
- Journal Name:
- The Cryosphere
- ISSN:
- 1787–1801
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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