Antarctic upper mantle rheology

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

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

17 Citations (Scopus)
39 Downloads (Pure)

Abstract

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.

Original languageEnglish
Pages (from-to)267-294
Number of pages28
JournalGeological Society Memoir
Volume56
Issue number1
DOIs
Publication statusPublished - 2023

Funding

Funding This research was carried out at the Jet Propulsion Laboratory (JPL), California Institute of Technology, under a contract with the National Aeronautics and Space Administration (NASA) and funded through NASA Post-doctoral Program, and through NASA’s Earth Surface and Interior Focus Area Program (grant NNH15ZDA001N-ESI to E.R. Ivins), the Sea-Level Change Science Team (grant NNH16ZDA001N-SLCT to E.R. Ivins), the GRACE Follow-On Science Team (grant NNH19ZDA001N-GRACEFO to E.R. Ivins) and the NASA Cryosphere Program (grant NNH13ZDA001N-SLR to E.R. Ivins).

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