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 22 dynamic, 3-D ruptures on extended faults, governed by different friction laws, including slip-dependent and 23 rate- and state-dependent equations.We analyze the spatial correlations between the peak of fault slip velocity 24 (vpeak) and the rupture speed (vr) at which the earthquake spreads over the fault.We found that vpeak positively 25 correlates with vr and that the increase of vpeak is roughly quadratic.We found that near the transition between 26 sub- and supershear regimes vpeak significantly diminishes and then starts to increase againwith the square of vr . 27 This holds for all the governing models we consider and for both homogeneous and heterogeneous configura- 28 tions. Moreover, we found that, on average, vpeak increases with the magnitude of the event (vpeak~M0 0.18). Our 29 results can be incorporated as constraints in the inverse modeling of faults.