A new Glacial Isostatic Adjustment model for Antarctica (Invited)
Abstract
We present a glacial isostatic adjustment (GIA) model which is based on a new reconstruction of ice mass changes in Antarctica during the last glacial cycle. The ice sheet reconstruction was constrained using a continent-wide dataset of glacial geological and glaciological data, and generated using a numerical ice sheet model driven by spatial and temporal variations in temperature and accumulation rate. This reconstruction of the Antarctic ice sheet was then incorporated into a global history of ice mass change in order to solve the sea-level equation and make predictions of past relative sea-level change, as well as present-day land uplift and geoid rates, for a range of earth models. The earth model component of the GIA model was then tuned using near-field observations of relative sea-level change. The sparse distribution of both relative sea-level data and glacial geological data limits the degree to which we can constrain past ice mass changes and Earth structure using the above procedure, therefore, a range of uncertainty will feed into our new GIA model parameters. We estimate this range, and attempt to differentiate between possible solutions using a newly reprocessed data set of GPS-determined vertical rates. Our new model will be used to provide improved estimates of present-day gravity changes due to GIA in Antarctica. In the future these results will be applied to the interpretation of GRACE data; thus enabling tighter constraints to be placed on the magnitude and source of present-day ice mass change in Antarctica.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2010
- Bibcode:
- 2010AGUFM.G34A..05W
- Keywords:
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- 0798 CRYOSPHERE / Modeling;
- 1223 GEODESY AND GRAVITY / Ocean/Earth/atmosphere/hydrosphere/cryosphere interactions;
- 1621 GLOBAL CHANGE / Cryospheric change;
- 1641 GLOBAL CHANGE / Sea level change