Volume 23, Issue 9 p. 957-960

Antarctic Ice Sheet melting in the southeast Pacific

Stanley S. Jacobs

Stanley S. Jacobs

Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY

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Hartmut H. Hellmer

Hartmut H. Hellmer

Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY

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Adrian Jenkins

Adrian Jenkins

British Antarctic Survey, Cambridge, UK

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First published: 01 May 1996
Citations: 12

Abstract

The first oceanographic measurements across a deep channel beneath the calving front of Pine Island Glacier reveal a sub-ice circulation driven by basal melting of 10–12 m yr−1. A salt box model described here gives a melt rate similar to that of ice balance and numerical models, 5–50 times higher than averages for the George VI and Ross Ice Shelves. Melting is fueled by relatively warm Circumpolar Deep Water that floods the deep floor of the Amundsen and Bellingshausen Sea continental shelves, reaching the deep draft of this floating glacier. A revised melt rate for ice shelves in the Southeast Pacific sector raises circumpolar ice shelf melting to 756 Gt yr−1. Given prior estimates of surface accumulation and iceberg calving, this suggests that the Antarctic Ice Sheet is currently losing mass to the ocean.