Using GPS and Gravity to Measure Postglacial Rebound
We compare vertical rates of deformation derived
from continuous global positioning system
(GPS) observations and episodic measurements of absolute
gravity. We concentrate on 4 sites in
a region of North America experiencing
postglacial rebound.
The rates of uplift from gravity and GPS
agree within one standard deviation for all sites.
The GPS vertical deformation rates are significantly more precise
than the gravity rates, primarily because of the denser
temporal spacing provided by continuous GPS tracking.
We conclude that continuous
GPS observations are more cost efficient and provide
more precise estimates of vertical deformation
rates than campaign style gravity observations
where systematic errors are difficult to quantify.
This paper was published in the December 1, 2000 issue of
Geophysical Research Letters. You can access the pdf file
here
or you can ask me for a reprint.