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Widespread low rates of Antarctic glacial isostatic adjustment revealed by GPS observations
journal contribution
posted on 2023-05-17, 23:06 authored by Thomas, ID, Matt KingMatt King, Bentley, MJ, Whitehouse, PL, Penna, NT, Williams, SDP, Riva, REM, Lavallee, DA, Clarke, PJ, King, EC, Hindmarsh, RCA, Koivula, HBedrock uplift in Antarctica is dominated by a combination of glacial isostatic adjustment (GIA) and elastic response to contemporary mass change. Here, we present spatially extensive GPS observations of Antarctic bedrock uplift, using 52% more stations than previous studies, giving enhanced coverage, and with improved precision. We observe rapid elastic uplift in the northern Antarctic Peninsula. After considering elastic rebound, the GPS data suggests that modeled or empirical GIA uplift signals are often over‐estimated, particularly the magnitudes of the signal maxima. Our observation that GIA uplift is misrepresented by modeling (weighted root‐mean-squares of observation‐model differences: 4.9–5.0 mm/yr) suggests that, apart from a few regions where large ice mass loss is occurring, the spatial pattern of secular ice mass change derived from Gravity Recovery and Climate Experiment (GRACE) data and GIA models may be unreliable, and that several recent secular Antarctic ice mass loss estimates are systematically biased, mainly too high.
History
Publication title
Geophysical Research LettersVolume
38Issue
22Article number
L22302Number
L22302Pagination
1-6ISSN
0094-8276Department/School
School of Geography, Planning and Spatial SciencesPublisher
Amer Geophysical UnionPlace of publication
2000 Florida Ave Nw, Washington, USA, Dc, 20009Rights statement
Copyright 2011 American Geophysical UnionRepository Status
- Restricted