Incomplete separability of Antarctic plate rotation from glacial isostatic adjustment deformation within geodetic observations

King, M.A.; Whitehouse, P.L.; van der Wal, W.

Abstract

Geodetic measurements of Antarctic solid Earth deformation include signals from plate rotation and glacial isostatic adjustment (GIA). Through simulation, we investigate the degree to which these signals are separable within horizontal GPS site velocities that commonly define plate rotation estimates and that promise new constraints on models of GIA. Using a suite of GIA model predictions that incorporate both 1-D and 3-D Earth rheologies, we show that, given the present location of GPS sites within East Antarctica, unmodelled or mismodelled GIA signal within GPS velocities produces biased estimates of plate rotation. When biased plate rotation is removed from the GPS velocities, errors as large as 0.8 mm yr−1 are introduced; a value commonly larger than the predicted GIA signal magnitude. In the absence of reliable forward models of plate rotation or GIA then Antarctic geodetic velocities cannot totally and unambiguously constrain either process, especially GIA.

Citation

King, M., Whitehouse, P., & van der Wal, W. (2016). Incomplete separability of Antarctic plate rotation from glacial isostatic adjustment deformation within geodetic observations. Geophysical Journal International, 204(1), 324-330. https://doi.org/10.1093/gji/ggv461

• Journal Article Type: Article
• Acceptance Date: Oct 20, 2015
• Online Publication Date: Jul 7, 2015
• Publication Date: Jan 1, 2016
• Deposit Date: Oct 20, 2015
• Publicly Available Date: Feb 11, 2016
• Journal: Geophysical Journal International
• Print ISSN: 0956-540X
• Electronic ISSN: 1365-246X
• Publisher: Oxford University Press
• Peer Reviewed: Peer Reviewed
• Volume: 204
• Issue: 1
• Pages: 324-330
• DOI: https://doi.org/10.1093/gji/ggv461
• Keywords: Space geodetic surveys, Plate motions, Tectonics and climatic interactions, Antarctica.
• Public URL: https://durham-repository.worktribe.com/output/1420147