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Lower satellite-gravimetry estimates of Antarctic sea-level contribution

Citation

King, MA and Bingham, RJ and Moore, P and Whitehouse, PL and Bentley, MJ and Milne, GA, Lower satellite-gravimetry estimates of Antarctic sea-level contribution, Nature, 491, (7425) pp. 586-590. ISSN 0028-0836 (2012) [Refereed Article]

Copyright Statement

Copyright 2012 Macmillan Publishers Limited

DOI: doi:10.1038/nature11621

Abstract

Recent estimates of Antarctica's present-day rate of ice-mass contribution to changes in sea level range from 31 gigatonnes a year (Gt yr -1; ref. 1) to 246 Gt yr -1 (ref. 2), a range that cannot be reconciled within formal errors. Time-varying rates of mass loss contribute to this, but substantial technique-specific systematic errors also exist. In particular, estimates of secular ice-mass change derived from Gravity Recovery and Climate Experiment (GRACE) satellite data are dominated by significant uncertainty in the accuracy of models of mass change due to glacial isostatic adjustment (GIA). Here we adopt a new model of GIA, developed from geological constraints, which produces GIA rates systematically lower than those of previous models, and an improved fit to independent uplift data. After applying the model to 99 months (from August 2002 to December 2010) of GRACE data, we estimate a continent-wide ice-mass change of -69 ± 18 Gt yr -1 (+0.19 ± 0.05 mm yr -1 sea-level equivalent). This is about a third to a half of the most recently published GRACE estimates, which cover a similar time period but are based on older GIA models. Plausible GIA model uncertainties, and errors relating to removing longitudinal GRACE artefacts ('destriping'), confine our estimate to the range -126 Gt yr -1 to -29 Gt yr -1 (0.08-0.35 mm yr -1 sea-level equivalent). We resolve 26 independent drainage basins and find that Antarctic mass loss, and its acceleration, is concentrated in basins along the Amundsen Sea coast. Outside this region, we find that West Antarctica is nearly in balance and that East Antarctica is gaining substantial mass.

Item Details

Item Type:Refereed Article
Research Division:Earth Sciences
Research Group:Physical Geography and Environmental Geoscience
Research Field:Physical Geography and Environmental Geoscience not elsewhere classified
Objective Division:Expanding Knowledge
Objective Group:Expanding Knowledge
Objective Field:Expanding Knowledge in the Earth Sciences
Author:King, MA (Professor Matt King)
ID Code:83481
Year Published:2012
Web of Science® Times Cited:89
Deposited By:Geography and Environmental Studies
Deposited On:2013-03-14
Last Modified:2017-10-27
Downloads:1 View Download Statistics

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