Isostatic Rebound Caused by Antarctic Deglaciation

    John Wahr and Isabella Velicogna
	University of Colorado at Boulder


The glaciation/deglaciation cycle of the Antarctic ice
sheet acts as a time-variable load on the Earth's surface,
causing vertical crustal motion.  That motion
presumably feeds back into the
deglaciation process, with consequences 
that depend on the amplitude and time-scale of 
the Earth response to surface loading.
Those characteristics, in turn, depend on the
Earth's viscosity structure beneath
Antarctica, which is not well constrained.
In this talk I will discuss the 
likely range of spatial and temporal
crustal uplift patterns under a glaciating/deglaciating Antarctica, and 
the sensitivity of those patterns to the viscosity
profile.  I will assume a radially dependent but
laterally-homogeneous viscosity.
I will discuss various possible geodetic methods
for observing and constraining this rebound;
methods that include combinations of ice sheet altimetry,
time-variable satellite gravity, and GPS.