Rupture speed and slip velocity: What can we learn from simulated earthquakes?

Abstract

In this paper we consider a wide catalog of synthetic earthquakes, numerically modeled as spontaneous, fully dynamic, 3-D ruptures on extended faults, governed by different friction laws, including slip-dependent and rate- and state-dependent equations.We analyze the spatial correlations between the peak of fault slip velocity (v_peak) and the rupture speed (v_r) at which the earthquake spreads over the fault. We found that vpeak positively correlates with vr and that the increase of v_peak is roughly quadratic. We found that near the transition between sub- and supershear regimes vpeak significantly diminishes and then starts to increase againwith the square of v_r. This holds for all the governing models we consider and for both homogeneous and heterogeneous configurations. Moreover, we found that, on average, v_peak increases with the magnitude of the event (v_peak~M_0^0.18). Our results can be incorporated as constraints in the inverse modeling of faults.