Publication Date:
2016-10-30
Description:
A recent data campaign in the East Siberian Sea has revealed evidence of grounded and floating ice
dynamics in regions of up to 1000 m water depth, and which are attributed to glaciations older than the
Last Glacial Maximum (21 kyrs BP). The main hypothesis based on this evidence is that a small ice cap
developed over Beringia and expanded over the East Siberian continental margin during some of the Late
Pleistocene glaciations. Other similar evidence of ice dynamics that have been previously collected on the
shallow continental shelves of the Arctic Ocean have been attributed to the penultimate glaciation, i.e.
Marine Isotopes Stage 6 (z 140 kyrs BP). We use an ice sheet model, forced by two previously simulated
MIS 6 glacial maximum climates, to carry out a series of sensitivity experiments testing the impact of
dynamics and mass-balance related parameters on the geometry of the East Siberian ice cap and ice
shelf. Results show that the ice cap developing over Beringia connects to the Eurasian ice sheet in all
simulations and that its volume ranges between 6 and 14 m SLE, depending on the climate forcing. This
ice cap generates an ice shelf of dimensions comparable with or larger than the present-day Ross ice shelf
in West Antarctica. Although the ice shelf extent strongly depends on the ice flux through the grounding
line, it is particularly sensitive to the choice of the calving and basal melting parameters. Finally,
inhibiting a merging of the Beringia ice cap with the Eurasian ice sheet affects the expansion of the ice
shelf only in the simulations where the ice cap fluxes are not large enough to compensate for the fluxes
coming from the Eurasian ice sheet.
Repository Name:
EPIC Alfred Wegener Institut
Type:
Article
,
isiRev
Format:
application/pdf
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