Quantifying the interplay between fast and slow earthquakes along the Mexican subduction zone

Subduction zones are among the most seismically active regions in the world, producing more than half of the global seismicity, releasing most of the total seismic energy, and hosting the largest known earthquakes and slow slip events (SSEs). SSEs and “fast” earthquakes are observed to coexist, interact, and complement each other at subduction margins, raising seismological questions with significant implications for earthquake and tsunami hazard assessments. Over the past two decades, almost 50 M_w ≥ 5.0 SSEs have been recorded in Mexico, and at least six of them began shortly after M_w ≥ 7.0 fast earthquakes. Here, we statistically quantify the interaction between regular earthquakes and SSEs along the Mexican subduction zone by analysing variations in seismological (e.g., Gutenberg-Richter a- and b-values), geodetic (e.g., seismic coupling), and kinematic (e.g., surface velocities) parameters before, during, and after the occurrence of SSEs. To do this, we use a catalogue of M_w ≥ 4.0 declustered seismicity, long-term estimates of interseismic strain rates based on GNSS data, and detailed SSE source models. Preliminary results indicate that the largest SSEs in Mexico tend to be shallow (d ≤ 30 km), spatially coinciding with relatively large crustal deformation rates (above 3.0 x 10^-7 / year)  and nucleating at a distance of approximately 20 km from historical M_w ≥ 7.0 interface earthquake ruptures.