Measurements of Time-Variable Gravity Show Mass Loss in Antarctica

Isabella Velicogna,John Wahr

doi:10.1126/science.1123785

Abstract

Using measurements of time-variable gravity from the Gravity Recovery and Climate Experiment satellites, we determined mass variations of the Antarctic ice sheet during 2002-2005. We found that the mass of the ice sheet decreased significantly, at a rate of 152 +/- 80 cubic kilometers of ice per year, which is equivalent to 0.4 +/- 0.2 millimeters of global sea-level rise per year. Most of this mass loss came from the West Antarctic Ice Sheet.

Highlights

Using measurements of time-variable gravity from the Gravity Recovery and Climate Experiment satellites, we determined mass variations of the Antarctic ice sheet during 2002–2005
The most recent Intergovernmental Panel on Climate Change (IPCC) assessment estimated that the Antarctic contribution to sea-level rise during the past century was 0.2 T 0.3 mm/year [2]
The gravitational survey of Antarctica provided by the Gravity Recovery and Climate Experiment (GRACE) satellites and discussed in this paper is a comprehensive survey of the entire ice sheet and is able to overcome the issue of limited sampling

Summary

Introduction

Using measurements of time-variable gravity from the Gravity Recovery and Climate Experiment satellites, we determined mass variations of the Antarctic ice sheet during 2002–2005. GRACE [5] provides monthly estimates of Earth_s global gravity field at scales of a few hundred kilometers and larger. We used GRACE gravity-field solutions for 34 months between April 2002 and August 2005 to estimate the mass change of the Antarctic ice sheet.

Results

Conclusion