[J01-2] Monitoring of the cryosphere II

[J01-2-05] 5000 Year Advance and Retreat Models for West Antarctica and a Geodetically Based Solution for Mantle Viscosity and More Recent and Accelerated Cryospheric Loss

^○Erik Ivins¹, Helene Seroussi¹, Lambert Caron¹, Surendra Adhikari¹, Eric Larour¹, Douglas Wiens², Andrew Lloyd², Mirko Scheinert³ (1.Jet Propulsion Lab, California Institute of Technology, Pasadena, USA, 2.Washington University, Saint Louis, USA, 3.University of Dresden, Dresden, Germany)

We model the present-day time-dependent bedrock motion of Antarctica driven by deep Earth elastic and viscous-gravitational response to continent-wide glacial mass changes. During the past two decades ice mass balance assessment has been achieved using space-based imaging and surface mass balance (SMB) modelling, altimetry and SMB, and with GRACE time-varying gravity. Crustal uplift trends are only recently emerging as a reliable source of constraint from data employed in the POLENET Project using Global Positioning System (GPS) geodesy. Two other observations have also emerged in the last decade: seismic imaging on the upper mantle and transition zone, at various levels of resolution, and rough maps of the basal hydrology that reveal channels and lake activity to be rather pervasive in many part of west Antarctica. The latter two advances in our knowledge were poorly integrated into models of mantle and ice history, the two main features that control predictions of glacial isostatic adjustment (GIA) in West Antarctica. Numerous models have emerged using the seismic imaging of the shallow upper mantle to compute GIA with laterally varying viscosity. Here we present new results of a traditionally radially layered model with updated ice history and seismically informed upper mantle viscosity structure and relatively free lower mantle viscosity.