American Geophysical Union Become an AGU Member
Subscribe to AGU Journals		 AGU Home AGU Publications

Read Full Article (file size: 317959 bytes)    Cited by

GEOPHYSICAL RESEARCH LETTERS, VOL. 31, L24605, doi:10.1029/2004GL021435, 2004

Climate-driven deformation of the solid Earth from GRACE and GPS

J. L. Davis

Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts, USA


P. Elósegui

Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts, USA


J. X. Mitrovica

Department of Physics, University of Toronto, Ontario, Canada


M. E. Tamisiea

Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts, USA


Abstract

GRACE data indicate large seasonal variations in gravity that are assumed to be related to climate-driven fluxes of surface water. Seasonal redistribution of surface mass should deform the Earth, and our calculations using GRACE data suggest vertical deformations of ∼13 mm in the region of greatest flux, the Amazon River Basin. To test the GRACE gravity-hydrology connection, we analyzed GPS data acquired from sites in this region. After accounting for degree 1 variations not observable with GRACE, we find that annual deformation measured with GPS correlates highly with predictions calculated from GRACE measurements. These results confirm the variations in surface water sensed by GRACE, which are significantly larger than those predicted by some hydrology models. The results also demonstrate that GRACE can be an important tool for monitoring deformation of the Earth, and suggest that combined analysis of GRACE and GPS may be a useful approach for estimation of geocenter variations.

Received 7 September 2004; accepted 29 October 2004; published 22 December 2004.

Index Terms: 1214 Geodesy and Gravity: Geopotential theory and determination; 1208 Geodesy and Gravity: Crustal movements—intraplate (8110); 1229 Geodesy and Gravity: Reference systems; 1243 Geodesy and Gravity: Space geodetic surveys; 1833 Hydrology: Hydroclimatology.

Read Full Article (file size: 317959 bytes)    Cited by

Citation: Davis, J. L., P. Elósegui, J. X. Mitrovica, and M. E. Tamisiea (2004), Climate-driven deformation of the solid Earth from GRACE and GPS, Geophys. Res. Lett., 31, L24605, doi:10.1029/2004GL021435.