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Accelerated sea-level rise from West Antarctica
R Thomas1, E Rignot, G Casassa
1EG&G Inc., NASA Goddard Space Flight Center (GSFC)/Wallops Flight Facility (WFF), Building N-159, Wallops Island, VA 23337, USA. thomas@osb.wff.nasa.gov
Science (New York, N.Y.)
|September 25, 2004
Summary
West Antarctic glaciers are losing ice faster than accumulating it, discharging 250 cubic kilometers annually. This significant ice loss contributes to global sea-level rise, indicating potential ice-sheet instability.
Area of Science:
- Glaciology
- Climate Science
- Oceanography
Background:
- Recent surveys reveal accelerated ice discharge from West Antarctic glaciers into the Amundsen Sea.
- Glacier thinning rates have increased significantly between the 1990s and 2002-2003.
Purpose of the Study:
- To quantify the ice discharge from Amundsen Sea glaciers.
- To assess the contribution of this discharge to global sea-level rise.
- To investigate the underlying geological structures influencing glacier flow.
Main Methods:
- Aircraft and satellite laser altimetry surveys.
- Analysis of glacier catchment basin accumulation rates.
- Bedrock depth estimation using altimetry data.
Main Results:
- Glaciers are discharging approximately 250 cubic kilometers of ice annually.
- Ice discharge exceeds accumulation by nearly 60%, indicating a net loss.
- This discharge contributes over 0.2 millimeters per year to global sea-level rise.
- Glacier thinning rates have markedly increased in the early 2000s.
- Bedrock beneath ice shelves is deeper than previously estimated, potentially facilitating further ice flow.
Conclusions:
- The Amundsen Sea sector is experiencing substantial ice loss, exceeding accumulation.
- Accelerated glacier discharge poses a significant threat to global sea levels.
- Deeper bedrock may enable continued ice flow from inland areas, suggesting potential ice-sheet instability.
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