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Reduced ice mass loss and three-dimensional viscoelastic deformation in northern Antarctic Peninsula inferred from GPS

Citation

Samrat, NH and King, MA and Watson, C and Hooper, A and Chen, X and Barletta, VR and Bordoni, A, Reduced ice mass loss and three-dimensional viscoelastic deformation in northern Antarctic Peninsula inferred from GPS, Geophysical Journal International, 222, (2) pp. 1013-1023. ISSN 0956-540X (2020) [Refereed Article]


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Copyright Statement

Copyright The Author(s) 2020. Published by Oxford University Press on behalf of The Royal Astronomical Society

DOI: doi:10.1093/gji/ggaa229

Abstract

We consider the viscoelastic rheology of the solid Earth under the Antarctic Peninsula due to ice mass loss that commenced after the breakup of the Larsen-B ice shelf. We extend the previous analysis of nearby continuous GPS time-series to include five additional years and the additional consideration of the horizontal components of deformation. They show strong uplift from ∼2002 to 2011 followed by reduced uplift rates to 2018. Modelling the GPS-derived uplift as a viscoelastic response to ongoing regional ice unloading from a new ice model confirms earlier estimates of low upper-mantle viscosities of ∼0.3–3 × 1018 Pa s in this region but allows a wide range of elastic lithosphere thickness. The observed and modelled north coordinate component shows little nonlinear variation due to the location of ice mass change to the east of the GPS sites. However, comparison of the observed and modelled east coordinate component constrains the upper-mantle viscosity to be less than ∼9 × 1018 Pa s, consistent with the viscosity range suggested by the uplift rates alone and providing important, largely independent, confirmation of that result. Our horizontal analysis showed only marginal sensitivity to modelled lithospheric thickness. The results for the horizontal components are sensitive to the adopted plate rotation model, with the estimate based on ITRF2014 suggesting that the sum of residual plate motion and pre-2002 glacial isostatic adjustment is likely less than ∼±0.5 mm yr−1 in the east component.

Item Details

Item Type:Refereed Article
Keywords:GPS, Antarctic Peninsula, glacial isostatic adjustment, satellite geodesy, space geodetic surveys, Antarctica, dynamics of lithosphere and mantle, rheology, crust and lithosphere, mantle
Research Division:Earth Sciences
Research Group:Geophysics
Research Field:Geodesy
Objective Division:Expanding Knowledge
Objective Group:Expanding knowledge
Objective Field:Expanding knowledge in the earth sciences
UTAS Author:Samrat, NH (Mr Nahidul Samrat)
UTAS Author:King, MA (Professor Matt King)
UTAS Author:Watson, C (Dr Christopher Watson)
ID Code:139276
Year Published:2020
Web of Science® Times Cited:1
Deposited By:Geography and Spatial Science
Deposited On:2020-06-04
Last Modified:2020-08-17
Downloads:5 View Download Statistics

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