Unraveling Scaling Properties of Slow-Slip Events

A major debate in geophysics is whether earthquakes and slow-slip events (SSEs) arise from similar failure mechanisms. Recent observations from different subduction zones suggest that SSEs follow the same moment-duration scaling as earthquakes, unlike qualitatively different scaling proposed by earlier studies. Here, we examine the scaling properties using dynamic simulations of frictional sliding. The resulting sequences of SSEs match observations from the Cascadia subduction zone, including the earthquake-like cubic moment-duration scaling. In contrast to conventional and widely used assumptions of magnitude-invariant rupture velocities and stress drops, both simulated and natural SSEs have rupture velocities and stress drops that increase with event magnitudes. These findings support the same frictional origin for both earthquakes and SSEs while suggesting a new explanation for the observed SSEs scaling.