23 November 2009

Antarctic ice sheet melt

A study by researchers from the University of Texas using data from GRACE satellites indicates that the East Antarctic ice sheet is melting faster than previous thought. Abstract from Nature Geoscience
Accelerated Antarctic ice loss from satellite gravity measurements

J. L. Chen1, C. R. Wilson1,2, D. Blankenship3 & B. D. Tapley1

Accurate quantification of Antarctic ice-sheet mass balance and its contribution to global sea-level rise remains challenging, because in situ measurements over both space and time are sparse. Satellite remote-sensing data of ice elevations and ice motion show significant ice loss in the range of -31 to -196 Gt yr-1 in West Antarctica in recent years1, 2, 3, 4, whereas East Antarctica seems to remain in balance or slightly gain mass1, 2, 4, with estimated rates of mass change in the range of -4 to 22 Gt yr-1. The Gravity Recovery and Climate Experiment5 (GRACE) offers the opportunity of quantifying polar ice-sheet mass balance from a different perspective6, 7. Here we use an extended record of GRACE data spanning the period April 2002 to January 2009 to quantify the rates of Antarctic ice loss. In agreement with an independent earlier assessment4, we estimate a total loss of 190plusminus77 Gt yr-1, with 132plusminus26 Gt yr-1 coming from West Antarctica. However, in contrast with previous GRACE estimates, our data suggest that East Antarctica is losing mass, mostly in coastal regions, at a rate of -57plusminus52 Gt yr-1, apparently caused by increased ice loss since the year 2006.

  1. Center for Space Research, University of Texas at Austin, Austin, Texas 78759, USA
  2. Department of Geological Sciences, Jackson School of Geosciences, University of Texas at Austin, Austin, Texas 78712, USA
  3. Institute for Geophysics, Jackson School of Geosciences, University of Texas at Austin, Austin, Texas 78712, USA

Correspondence to: J. L. Chen1 e-mail: chen@csr.utexas.edu

See reporting by ABC (Aust), BBC, Reuters, AFP and Bloomberg.

57 billion tonnes is a lot of ice to melt. What a shame that climate change and global warming issues have become politicised. It would be an interesting exercise to see which American media outlets pick up this story without any spin, either way.

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