Sustained retreat of the Pine Island Glacier

We use satellite observations to show that, between 1992 and 2011, the Pine Island Glacier hinge line retreated at a rate of 0.95 ± 0.09 km yr−1 despite a progressive steepening and shoaling of the glacier surface and bedrock slopes, respectively, which ought to impede retreat. The retreat has remai...

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Bibliographic Details
Published in:Geophysical Research Letters
Main Authors: Park, J. W., Gourmelen, N., Shepherd, A., Kim, S. W., Vaughan, D. G., Wingham, D. J.
Format: Article in Journal/Newspaper
Language:English
Published: American Geophysical Union 2013
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Online Access:http://nora.nerc.ac.uk/id/eprint/502339/
https://nora.nerc.ac.uk/id/eprint/502339/1/grl50379.pdf
https://doi.org/10.1002/grl.50379
Description
Summary:We use satellite observations to show that, between 1992 and 2011, the Pine Island Glacier hinge line retreated at a rate of 0.95 ± 0.09 km yr−1 despite a progressive steepening and shoaling of the glacier surface and bedrock slopes, respectively, which ought to impede retreat. The retreat has remained constant because the glacier terminus has thinned at an accelerating rate of 0.53 ± 0.15 m yr−2, with comparable changes upstream. This acceleration is consistent with an intensification of ocean-driven melting in the cavity beneath the floating section of the glacier. The pattern of hinge-line retreat meanders and is concentrated in isolated regions until ice becomes locally buoyant. Because the glacier-ocean system does not appear to have reached a position of relative stability, the lower limit of sea level projections may be too conservative.