Regional biases in absolute sea-level estimates from tide gauge data due to residual unmodeled vertical land movement

Edited: 2012-08-07
TitleRegional biases in absolute sea-level estimates from tide gauge data due to residual unmodeled vertical land movement
Publication TypeJournal Article
Year of Publication2012
AuthorsKing, M., M. Keshin, P. Whitehouse, I. Thomas, G. Milne, and R. Riva
JournalGeophysical Research Letters
Volume39
Issue14
Date Published07/2012
ISSN0094-8276
Keywordsgia, sea_level, tide_gauge
AbstractThe 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.
DOI10.1029/2012GL052348
Short TitleGeophys. Res. Lett.