Antarctic upper mantle rheology

Antarctic upper mantle rheology

Ivins, E. R. (California Institute of Technology)
van der Wal, W. (TU Delft Astrodynamics & Space Missions)
Wiens, D. A. (Washington University in St. Louis)
Lloyd, A. J. (Lamont-Doherty Earth Observatory)
Caron, L. (California Institute of Technology; University of California)

2023

The Antarctic mantle and lithosphere are known to have large lateral contrasts in seismic velocity and tectonic history. These contrasts suggest differences in the response timescale of mantle flow across the continent, similar to those documented between the northeastern and southwestern upper mantle of North America. Glacial isostatic adjustment and geodynamical modelling rely on independent estimates of lateral variability in effective viscosity. Recent improvements in imaging techniques and the distribution of seismic stations now allow reso-lution of both lateral and vertical variability of seismic velocity, making detailed inferences about lateral viscosity variations possible. Geodetic and palaeosea-level investigations of Antarctica provide quantitative ways of independently assessing the 3D mantle viscosity structure. While observational and causal connections between inferred lateral viscosity variability and seismic velocity changes are qualitatively reconciled, significant improvements in the quantitative relations between effective viscosity anomalies and those imaged by P-and S-wave tomography have remained elusive. Here we describe several methods for estimating effective viscosity from S-wave velocity. We then present and com-pare maps of the viscosity variability beneath Antarctica based on the recent S-wave velocity model ANT-20 using three different approaches.

http://resolver.tudelft.nl/uuid:43cf9e4e-7e87-4de9-950e-30e253190ad2

https://doi.org/10.1144/M56-2020-19

0435-4052

Geological Society Memoir, 56 (1), 267-294

Institutional Repository

journal article

© 2023 E. R. Ivins, W. van der Wal, D. A. Wiens, A. J. Lloyd, L. Caron