RG Research: Geodesy
 Geodesy is the science of measurement of the size, shape, rotation, and gravitational field of the Earth. RG researchers specialize in acquiring, analyzing, interpreting space-based geodetic measurements, and improving the accuracy of such measurements. A variety of processes can influence geodetic measurements over a range of spatial and temporal scales, including:

  • tides of the solid Earth and the oceans;
  • weather and climate, and atmospheric structure and dynamics;
  • hydrology and continental water storage;
  • mass fluctuations and motions of glaciers and ice complexes;
  • ocean and atmospheric circulation;
  • changes in sea level;
  • crustal motion associated with plate tectonics, earthquakes, and volcanos;
  • postglacial rebound.
Project Links

Space Geodesy Group


James L. Davis, Eric Malikowski, Sarah Block

  Maps of seasonal radial crustal deformation

Maps of seasonal radial (i.e., vertical) crustal deformation in and around the Amazon Basin inferred from gravity variations measured by the NASA GRACE satellites.
The left frame shows the amplitude of the deformation on January 1, and the right frame shows the amplitude of the deformation on April 1. The gravity variations are assumed to arise from water that is redistributed seasonally on the surface of the Earth. The weight of the water should deform the crust of the Earth beneath it. The correctness of this hypothesis was demonstrated in Davis et al. 2004 by measuring the radial position variations at South American GPS sites (triangles with site names on right).


Section Photo