Glacial isostatic adjustment and post-seismic deformation in Antarctica

Glacial isostatic adjustment and post-seismic deformation in Antarctica

van der Wal, W. (TU Delft Geoscience and Remote Sensing; TU Delft Astrodynamics & Space Missions)
Barletta, Valentina (Technical University of Denmark)
Nield, Grace (Durham University; University of Tasmania)
van Calcar, C.J. (TU Delft Astrodynamics & Space Missions; Universiteit Utrecht)

Geoscience and Remote Sensing

2023

This chapter reviews glacial isostatic adjustment (GIA) and post-seismic deformation in Antarctica. It discusses numerical models and their inputs, and observations and inferences that have been made from them. Both processes are controlled by mantle viscosity but their forcings are different. Ongoing GIA induced by the loss of ice since the last glacial maximum (LGM) could have amounted to 5–15 m of global sea-level rise. However, mantle viscosity is so low in parts of West Antarctica (c. 10¹⁸ Pa s) that changes in ice thickness over the last centuries and decades have controlled the current uplift rates there. The uplift due to GIA has promoted ice-sheet stability since the LGM, and in West Antarctica GIA is a significant negative feedback on the current decline of the ice sheet. Post-seismic deformation following the 1998 earthquake near the Balleny Islands south of New Zealand has been detected in global navigation satellite system (GNSS) data and compared to model outputs. The best-fitting viscosity for this area is c. 10¹⁹ Pa s, similar to GIA-based estimates for the Antarctic Peninsula. Future work should focus on unifying descriptions of viscosity across geodynamic models, and integrating information from seismic, gravity, experimental and geological data.

http://resolver.tudelft.nl/uuid:ca4c793d-e4c2-430e-91ca-cd03e19b6a7a

https://doi.org/10.1144/M56-2022-13

0435-4052

Geological Society Memoir, 56 (1), 315-341

Institutional Repository

journal article

© 2023 W. van der Wal, Valentina Barletta, Grace Nield, C.J. van Calcar