Anticipating the Next Large Silent Earthquake in Mexico

Abstract

Silent earthquakes, or slow slip events (SSEs), in subduction zones [Schwartz and Rokosky, 2007] release accumulated strain energy within tens of minutes to a few months, as opposed to a few seconds or minutes for “regular” earthquakes [Kostoglodov et al., 2003]. This phenomenon has important implications for the seismic cycle because SSEs significantly modify the loading‐unloading budget of faults; their existence suggests that the buildup and relaxing mechanisms of the earthquake cycle are much more complex than previously thought.Numerous important questions have to be answered concerning SSEs, in particular, their specific location on the fault, the amount of slip at depth, and their recurrence. Depending on whether they occur on the seismogenic or creeping section of the fault, they may release some accumulated elastic strain or further load the brittle part of the fault, effectively lengthening or shortening the time before the next large regular earthquake. In that framework, assessing the repartition of the displacement on the subduction interface and the frequency of SSEs is of particular importance, because these parameters govern the extent to which SSEs may slow or accelerate the regular earthquake clock.