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Instability of the Antarctic Ross Sea Embayment as climate warms
Author(s) -
Hughes Terence,
Zhao Zihong,
Hintz Raymond,
Fastook James
Publication year - 2017
Publication title -
reviews of geophysics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 8.087
H-Index - 156
eISSN - 1944-9208
pISSN - 8755-1209
DOI - 10.1002/2016rg000545
Subject(s) - ice shelf , geology , ice sheet , ice stream , antarctic ice sheet , antarctic sea ice , oceanography , iceberg , ice calving , glacier , sea ice , ice divide , cryosphere , future sea level , arctic ice pack , glacier morphology , geomorphology , pregnancy , lactation , biology , genetics
Abstract Collapse of the Antarctic Ice Sheet since the Last Glacial Maximum 18,000 years ago is most pronounced in the Ross Sea Embayment, which is partly ice‐free during Antarctic summers, thereby breaching the O‐ring of ice shelves and sea ice surrounding Antarctica that stabilizes the ice sheet. The O‐ring may have vanished during Early Holocene (5000 to 3000 B.C.), Roman (1 to 400 A.D.), and Medieval (900 to 1300 A.D.) warm periods and reappeared during the Little Ice Age (1300 to 1900 A.D.). We postulate further collapse in the embayment during the post‐1900 warming may be forestalled because East Antarctic outlet glaciers “nail” the Ross Ice Shelf to the Transantarctic Mountains so it can resist the push from West Antarctic ice streams. Our hypothesis is examined for Byrd Glacier and a static ice shelf using three modeling experiments having plastic, viscous, and viscoplastic solutions as more data and improved modeling became available. Observed crevasse patterns were not reproduced. A new research study is needed to model a dynamic Ross Ice Shelf with all its feeder ice streams, outlet glaciers, and ice calving dynamics in three dimensions over time to fully test our hypothesis. The required model must allow accelerated calving if further warming melts sea ice and discerps the ice shelf. Calving must then successively pull the outlet glacier “nails” so collapse of the marine West Antarctic Ice Sheet proceeds to completion.