Project Details
Projekt
Advancing the understanding of glacial isostatic adjustment in Antarctica
Applicants
Dr. Volker Klemann; Dr.-Ing. Mirko Scheinert
Subject Area
Geophysics
Geodesy, Photogrammetry, Remote Sensing, Geoinformatics, Cartography
Geodesy, Photogrammetry, Remote Sensing, Geoinformatics, Cartography
Term
since 2025
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 562072489
The Antarctic Ice Sheet (AIS) plays a key role in global climate. Glacial isostatic adjustment (GIA) describing the solid Earth’s response to changing ice masses is one key process controlling the stability of the AIS. Crucial mechanisms like the marine ice sheet instability (MISI) are controlled by interactions between ocean, atmosphere, ice sheets and the solid Earth, and involve feedbacks with the vertical bedrock displacements associated with GIA. Investigating the role of GIA for the future sea-level contribution of the AIS requires improvements in GIA modelling. The rheology of the Earth, especially the upper-mantle viscosity structure, controls the temporal scale and spatial pattern of the GIA response to ice mass changes. However, GIA modelling in Antarctica suffers from an imprecise knowledge and implementation of the rheological structure of the solid Earth, in particular of lateral viscosity variations. The goal of the project is to decisively improve the understanding of GIA-driven processes and, hence, the GIA modelling in Antarctica. In view of the dynamic state of the AIS and a proposed mid-Holocene re-advance, we focus on glacial changes from the Holocene to present day. Combining Antarctic-wide GNSS observations with the consideration of a laterally heterogeneous Earth structure below Antarctica, we aim (1) to narrow down the uncertainty of GIA model output and resolve previous inconsistencies with GNSS observations, and (2) to bring GIA models to a level of fidelity that allows a better understanding of the distinct ice sheet–solid Earth interactions. To reach this goal, we will exploit the new quality and quantity of geophysical, geological and geodetic observational data (a) to better constrain the glacial history from the Holocene to the present day, (b) to better parametrise the structure and rheology of the Antarctic lithosphere and mantle, and (c) to better interpret bedrock displacements measured by GNSS. In addition to an analysis for the whole continent, we will focus on three specific regions, which are the Amundsen Sea Embayment in West Antarctica, the Indian Sector and Dronning Maud Land in East Antarctica, to scrutinise the deformation process in response to present and past ice-load changes in high granularity. In this respect, a major aim is to assess the uncertainty space regarding the mechanisms controlling the GIA process and to close current caveats in the GIA modelling of Antarctica.
DFG Programme
Infrastructure Priority Programmes
