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Title: Mid-Holocene Antarctic sea-ice increase driven by marine ice sheet retreat
Abstract. Over recent decades Antarctic sea-ice extent has increased, alongsidewidespread ice shelf thinning and freshening of waters along the Antarcticmargin. In contrast, Earth system models generally simulate a decrease insea ice. Circulation of water masses beneath large-cavity ice shelves is notincluded in current Earth System models and may be a driver of thisphenomena. We examine a Holocene sediment core off East Antarctica thatrecords the Neoglacial transition, the last major baseline shift ofAntarctic sea ice, and part of a late-Holocene global cooling trend. Weprovide a multi-proxy record of Holocene glacial meltwater input, sedimenttransport, and sea-ice variability. Our record, supported by high-resolutionocean modelling, shows that a rapid Antarctic sea-ice increase during themid-Holocene (∼ 4.5 ka) occurred against a backdrop ofincreasing glacial meltwater input and gradual climate warming. We suggestthat mid-Holocene ice shelf cavity expansion led to cooling of surfacewaters and sea-ice growth that slowed basal ice shelf melting.Incorporating this feedback mechanism into global climate models will beimportant for future projections of Antarctic changes.  more » « less
Award ID(s):
1643845
PAR ID:
10355138
Author(s) / Creator(s):
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;
Date Published:
Journal Name:
Climate of the Past
Volume:
17
Issue:
1
ISSN:
1814-9332
Page Range / eLocation ID:
1 to 19
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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