Short-term interaction between silent and devastating earthquakes in Mexico

Either the triggering of large earthquakes on a fault hosting aseismic slip or the triggering of slow slip events (SSE) by passing seismic waves involve seismological questions with important hazard implications. Just a few observations plausibly suggest that such interactions actually happen in nature. In this study we show that three recent devastating earthquakes in Mexico are likely related to SSEs, describing a cascade of events interacting with each other on a regional scale via quasi-static and/or dynamic perturbations across the states of Guerrero and Oaxaca. Such interaction seems to be conditioned by the transient memory of Earth materials subject to the traumatic stress produced by seismic waves of the great 2017 (Mw8.2) Tehuantepec earthquake, which strongly disturbed the SSE cycles over a 650km long segment of the subduction plate interface. Our results imply that seismic hazard in large populated areas is a short-term evolving function of seismotectonic processes that are often observable. This study shows how seismic and aseismic events are related in Mexico between 2017 and 2019. Based on a series of observations and models, the study suggests that the Mw 8.2 intraslab earthquake of 8 September 2017 severely altered the mechanical properties of the plate interface, facilitating the interaction between the events and disrupting the slow slip cycles at a regional scale.

Automated summary

The study suggests that the devastating earthquakes in Mexico between 2017 and 2019 may be related to slow slip events. It shows how seismic and aseismic events are interrelated, with the Mw 8.2 intraslab earthquake of 8 September 2017 altering the mechanical properties of the plate interface and disrupting slow slip cycles at a regional scale.