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New boundary conditions for the West Antarctic ice sheet: Subglacial topography beneath Pine Island Glacier
Author(s) -
Vaughan David G.,
Corr Hugh F. J.,
Ferraccioli Fausto,
Frearson Nicholas,
O'Hare Aidan,
Mach Dieter,
Holt John W.,
Blankenship Donald D.,
Morse David L.,
Young Duncan A.
Publication year - 2006
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2005gl025588
Subject(s) - geology , antarctic ice sheet , glacier , glacier morphology , ice stream , ice sheet , deglaciation , geomorphology , cryosphere , tidewater glacier cycle , ice divide , antarctic sea ice , ice shelf , glacial period , oceanography , sea ice , ice calving , pregnancy , lactation , biology , genetics
Predictions about future changes in the Amundsen Sea sector of the West Antarctic ice sheet (WAIS) have been hampered by poorly known subglacial topography. Extensive airborne survey has allowed us to derive improved subglacial topography for the Pine Island Glacier basin. The trunk of this glacier lies in a narrow, 250‐km long, 500‐m deep sub‐glacial trough, suggesting a long‐lived and constrained ice stream. Two tributaries lie in similar troughs, others lie in less defined, shallower troughs. The lower basin of the glacier is surrounded by bedrock, which, after deglaciation and isostatic rebound, could rise above sea level. This feature would impede ice‐sheet collapse initiated near the grounding line of this glacier, and prevent its progress into the deepest portions of WAIS. The inland‐slope of the bed beneath the trunk of the glacier, however, confirms potential instability of the lower basin, containing sufficient ice to raise global sea by ∼24 cm.