Regional biases in absolute sea-level estimates from tide gauge data due to residual unmodeled vertical land movement
journal contribution
posted on 2023-05-17, 23:05authored byMatt KingMatt King, Keshin, M, Whitehouse, PL, Thomas, ID, Milne, G, Riva, REM
The only vertical land movement signal routinely corrected for when estimating absolute sea-level change from tide gauge data is that due to glacial isostatic adjustment (GIA). We compare modeled GIA uplift (ICE-5G + VM2) with vertical land movement at ~300 GPS stations located near to a global set of tide gauges, and find regionally coherent differences of commonly +-0.5-2 mm/yr. Reference frame differences and signal due to present-day mass trends cannot reconcile these differences. We examine sensitivity to the GIA Earth model by fitting to a subset of the GPS velocities and find substantial regional sensitivity, but no single Earth model is able to reduce the disagreement in all regions. We suggest errors in ice history and neglected lateral Earth structure dominate model-data differences, and urge caution in the use of modeled GIA uplift alone when interpreting regional- and global- scale absolute (geocentric) sea level from tide gauge data.
History
Publication title
Geophysical Research Letters
Volume
39
Issue
14
Article number
L14604
Number
L14604
Pagination
1-5
ISSN
0094-8276
Department/School
School of Geography, Planning and Spatial Sciences
Publisher
Amer Geophysical Union
Place of publication
2000 Florida Ave Nw, Washington, USA, Dc, 20009
Rights statement
Copyright 2012 American Geophysical Union
Repository Status
Restricted
Socio-economic Objectives
Understanding climate change not elsewhere classified