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Sensitivity of Barnes Ice Cap, Baffin Island, Canada, to climate state and internal dynamics
Author(s) -
Gilbert A.,
Flowers G. E.,
Miller G. H.,
Rabus B. T.,
Van Wychen W.,
Gardner A. S.,
Copland L.
Publication year - 2016
Publication title -
journal of geophysical research: earth surface
Language(s) - English
Resource type - Journals
eISSN - 2169-9011
pISSN - 2169-9003
DOI - 10.1002/2016jf003839
Subject(s) - geology , ice sheet , greenland ice sheet , ice stream , ice sheet model , glacial period , climatology , pleistocene , climate change , last glacial maximum , current (fluid) , holocene , physical geography , oceanography , cryosphere , geomorphology , sea ice , geography , paleontology
Barnes Ice Cap is a remnant of the Laurentide Ice Sheet, which covered much of northern North America during the Last Glacial Maximum. Barnes reached a quasi‐equilibrium state ~2000 years ago and has remained similar in size since then, with a small increase during the Little Ice Age. In this study, we combine historical observations (1960–1980) with more recent satellite and airborne data (1995–2010) to drive a mass balance model coupled to a transient thermomechanical model with an adaptive mesh geometry. The model is used to characterize the current state of the ice cap and to investigate its stability as a function of climate and its own internal dynamics. On millennial time scales we show that ice flow is influenced by adjustment of an unsteady shape, by gently sloping bedrock, and by contrasting viscosities between the Pleistocene and Holocene ice. On shorter time scales, Barnes is affected by surge activity. Sensitivity tests reveal that Barnes experienced climate conditions which enabled its stability 2000 to 3000 years ago but will disappear under current climate conditions in the next millennium.