Three-dimensional thermomechanical modelling beneath Guerrero, Mexico, and its relation to the occurrence of interplate seismic phenomena.

In this study, we investigated the relationships among the occurrence regions of megathrust earthquakes and slow earthquakes, estimated interplate temperatures, and dehydration processes at the plate interface in the subduction zone of the Cocos plate in Mexico, with a focus on the Guerrero seismic gap. For this purpose, we performed a series of 3-D thermomechanical numerical simulations of subduction based on a combination of multiple unknown model parameters. Comparing the temperature field for the optimal model with the occurrence region of the interplate seismic phenomena, the temperature along the slab surface where megathrust earthquakes tend to occur is estimated to range from 200 to 400 °C.