A COMPARISON BETWEEN SHORT-TERM (COSEISMIC) AND LONG-TERM (ONE-YEAR) SLIP FOR THE LANDERS EARTHQUAKE - MEASUREMENTS FROM STRONG-MOTION AND SAR INTERFEROMETRY

The long term relative displacements in the region of the Landers eart hquake were measured over a time interval of about one year using SAR interferometry. We have also evaluated the co-seismic slip distributio n through a strong motion inversion [Cotton and Campillo, 1995] and th ese results are used to compute the static displacement field associat ed with the coseismic slip. We show that the synthetic static and the interferometry measurements are in very good agreement. To give an eva luation of the magnitude of the pre- and post-seismic slip, a residual interferogram between data and synthetic co-seismic slip has been com puted. A simple analysis of the residual displacements gives a limitin g value of the amplitude of pre- and post-seismic slip integrated over a period of one year and suggests that it is on the order of a few de cimeters.