Combination of geodetic observations and models for glacial isostatic adjustment fields in Fennoscandia
Journal article, 2010

We demonstrate a new technique for using geodetic data to update a priori predictions for Glacial Isostatic Adjustment (GIA) in the Fennoscandia region. Global Positioning System (GPS), tide gauge, and Gravity Recovery and Climate Experiment (GRACE) gravity rates are assimilated into our model. The technique allows us to investigate the individual contributions from these data sets to the output GIA model in a self‐consistent manner. Another benefit of the technique is that we are able to estimate uncertainties for the output model. These are reduced with each data set assimilated. Any uncertainties in the GPS reference frame are absorbed by reference frame adjustments that are estimated as part of the assimilation. Our updated model shows a spatial pattern and magnitude of peak uplift that is consistent with previous models, but our location of peak uplift is slightly to the east of many of these. We also simultaneously estimate a spatially averaged rate of local sea level rise. This regional rate (∼1.5 mm/yr) is consistent for all solutions, regardless of which data sets are assimilated or the magnitude of a priori GPS reference frame constraints. However, this is only the case if a uniform regional gravity rate, probably representing errors in, or unmodeled contributions to, the low‐degree harmonic terms from GRACE, is also estimated for the assimilated GRACE data. Our estimated sea level rate is consistent with estimates obtained using a more traditional approach of direct “correction” using collocated GPS and tide gauge sites.

GRACE

Glacial Isostatic Adjustment

GPS

Author

Emma M. Hill

James L. Davis

Mark E. Tamisiea

Martin Lidberg

Chalmers, Department of Radio and Space Science, Space Geodesy and Geodynamics

Journal of Geophysical Research

01480227 (ISSN) 21562202 (eISSN)

Vol. 115 B07

Subject Categories

Geophysics

DOI

10.1029/2009JB006967

More information

Created

10/7/2017