Toggle Main Menu Toggle Search

Open Access padlockePrints

Lower satellite-gravimetry estimates of Antarctic sea-level contribution

Lookup NU author(s): Professor Matt King, Dr Rory Bingham, Professor Philip Moore

Downloads

Full text for this publication is not currently held within this repository. Alternative links are provided below where available.


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(3). Time-varying rates of mass loss(2,4-6) contribute to this, but substantial technique-specific systematic errors also exist(3). 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(7,8) (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(9). 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(2,5), 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.


Publication metadata

Author(s): King MA, Bingham RJ, Moore P, Whitehouse PL, Bentley MJ, Milne GA

Publication type: Article

Publication status: Published

Journal: Nature

Year: 2012

Volume: 491

Issue: 7425

Pages: 586-589

Print publication date: 01/11/2012

ISSN (print): 0028-0836

ISSN (electronic): 1476-4687

Publisher: Nature Publishing Group

URL: http://dx.doi.org/10.1038/nature11621

DOI: 10.1038/nature11621


Altmetrics

Altmetrics provided by Altmetric


Actions

Find at Newcastle University icon    Link to this publication


Share