Estimation of dynamic rupture parameters from the radiated seismic energy and apparent stress, Geophys

Abstract. We propose a new procedure for estimating the critical slip weakening distance, Dc, by evaluating the spatio-temporal distribution of the apparent stress calcu-lated from the spatio-temporal distribution of the slip ve-locity function on the fault plane obtained from a kinematic inversion of the earthquake source. The idea is based on the fact that the apparent stress can be related to the dierence between the earthquake average stress and the frictional dy-namical stress on the fault plane during the rupture process. From the cumulative slip- apparent stress relationship we estimate the critical slip, Dc, of the 1992 Landers earth-quake. We nd that the critical slip weakening plays an important role in controlling the rupture velocity. In the case of the Landers earthquake the very low rupture veloc-ity in the central segment could be explained by the large Dc-value obtained for the main asperity on that segment