GRADES-IMAGE: Inverse Modelling of Antarctica and Global Eustasy

GRADES will investigate the state and stability of the Antarctic ice sheet. The West Antarctic Ice Sheet (WAIS) may be unstable because its base lies on rock below sea level. Measurements from satellites show that there is currently a substantial imbalance in part of the WAIS, which is contributing significantly to sea-level rise. BAS and the University of Texas, supported by US logistics, have already completed an airborne radio-echo sounding survey of approximately one third of the WAIS, covering the region where the most rapid change is taking place. GRADES will study further this important area to better predict how the WAIS contributes to sea level rise. GRADES will also develop ice-sheet models and test them using newly acquired ice-sheet histories. We use satellite data, reconstructions of past states of the ice sheet, and new data assimilation techniques to learn more about how ice sheets develop and evolve.

Antarctica's vast ice sheets contain a volume of water equivalent to a sea-level rise of 57m. Even small percentage changes in this volume would have profound social and economic consequences worldwide, since hundreds of millions of people and much important infrastructure are located on low-lying coastal areas. We aim to improve our understanding of Antarctic deglaciation to allow us to predict future sea level rise more accurately. GRADES will analyse models of ice sheet evolution, covering a period from the last ice age to a thousand years into the future.We will use existing and new data to assess the stability of the WAIS and its contribution to future sea level rise. GRADES has links with GEACEP, CACHE, ACES, and COMPLEXITY.