*Jun'ichi Okuno1,2
(1.National Institute of Polar Research, 2.SOKENDAI)
Keywords:Glacial Isostatic Adjustment, Antarctic Ice Sheet, Viscosity of the Earth's mantle, Solid Earth response
Crustal deformation in Antarctica on scales of 10-10,000 years depends on multi-scale Antarctic ice sheet changes and viscoelastic properties of the Earth's interior. Therefore, observational data analysis alone makes it difficult to extract information on ice sheet changes and the Earth's internal structure from observations on the solid Earth crustal deformation in Antarctica. Accordingly, numerical modelling related to the solid Earth is required to emulate the deformation of the Earth in response to ice sheet changes. This problem has been mathematically formulated as a viscoelastic spherical shell deformation problem since the late 1970s. It has been applied to the last deglaciation of ice sheets in the Northern Hemisphere, and valuable results have been obtained for past sea levels and crustal movements worldwide. It is called Glacial Isostatic Adjustment (GIA), and the framework considers ice sheet fluctuations as a redistribution of ice and water loads on the Earth's surface and their viscoelastic response. We have been applying the numerical modelling of GIA to Antarctic observational data in the Solid Earth Group of the GRANTARCTIC Project. This presentation will explain the importance and problems of numerical modelling of GIA in Antarctica and describe the results obtained in the past five years. In addition, future research topics will be discussed.