Several viscoelastic models are being developed to provide end-member estimates of possible deformation following the Bhuj event. We are currently ignorant of the rheological properties, or depths of possible transitions to viscous behaviour in mid continent areas, because no great earthquake has hitherto occurred in these regions since the availability of precise geodetic methods.

A preliminary model developed by Fred Pollitz (USGS Menlo Park) is shown below.

The selected focal mechanism solution was developed by ERI. This solution is not perfect in that many of the sites do not fit Sh waves recorded teleseismically, however, the main features of the deformation field are obvious. The calculated strains and displacements are those that will occur between 2 months and 12 months after the earthquake.

The lower crust runs from 18 to 33 km depth, the fault from17.5 to 2.5 km depth, and all estimates are for the earth's surface

The selected viscosity of the crust and lower mantle are indicated with the suffixes c and m.

Horizontal displacement and strain (gamma1=eEE-eNN, gamma2=2eEN, where E=East, N=North)