Joint inversion estimate of regional glacial isostatic adjustment in Antarctica considering a lateral varying Earth structure (ESA STSE Project REGINA)

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • I. Sasgen - , Alfred Wegener Institute - Helmholtz Centre for Polar and Marine Research (Author)
  • A. Martín-Español - , University of Bristol (Author)
  • A. Horvath - , Technical University of Munich (Author)
  • V. Klemann - , Helmholtz Centre Potsdam - German Research Centre for Geosciences (Author)
  • E. J. Petrie - , University of Glasgow (Author)
  • B. Wouters - , Utrecht University (Author)
  • M. Horwath - , Chair of Geodetic Earth System Research (Author)
  • R. Pail - , Technical University of Munich (Author)
  • J.L. Bamber - , University of Bristol (Author)
  • P.J. Clarke - , Newcastle University (Author)
  • H. Konrad - , University of Leeds (Author)
  • M.R. Drinkwater - , ESTEC - European Space Research and Technology Centre (Author)

Abstract

A major uncertainty in determining the mass balance of the Antarctic ice sheet from measurements of satellite gravimetry, and to a lesser extent satellite altimetry, is the poorly known correction for the ongoing deformation of the solid Earth caused by glacial isostatic adjustment (GIA). Although much progress has been made in consistently modeling the ice-sheet evolution throughout the last glacial cycle, as well as the induced bedrock deformation caused by these load changes, forward models of GIA remain ambiguous due to the lack of observational constraints on the ice sheet's past extent and thickness and mantle rheology beneath the continent. As an alternative to forward-modeling GIA, we estimate GIA from multiple space-geodetic observations: Gravity Recovery and Climate Experiment (GRACE), Envisat/ICESat and Global Positioning System (GPS). Making use of the different sensitivities of the respective satellite observations to current and past surface-mass (ice mass) change and solid Earth processes, we estimate GIA based on viscoelastic response functions to disc load forcing. We calculate and distribute the viscoelastic response functions according to estimates of the variability of lithosphere thickness and mantle viscosity in Antarctica. We compare our GIA estimate with published GIA corrections and evaluate its impact in determining the ice-mass balance in Antarctica from GRACE and satellite altimetry. Particular focus is applied to the Amundsen Sea Sector in West Antarctica, where uplift rates of several centimetres per year have been measured by GPS. We show that most of this uplift is caused by the rapid viscoelastic response to recent ice-load changes, enabled by the presence of a low-viscosity upper mantle in West Antarctica. This paper presents the second and final contributions summarizing the work carried out within a European Space Agency funded study, REGINA (www.regina-science.eu).

Details

Original languageEnglish
Pages (from-to)1534-1553
JournalGeophysical Journal International
Publication statusPublished - Dec 2017
Peer-reviewedYes

External IDs

Scopus 85043579954
ORCID /0000-0001-5797-244X/work/142246507

Keywords

DFG Classification of Subject Areas according to Review Boards

Subject groups, research areas, subject areas according to Destatis

ASJC Scopus subject areas

Keywords

  • Geodäsie