The brittle-ductile transition as the switch of earthquakes: applications for seismic prediction

Abstract

The brittle-ductile transition (BDT) separates the lower crust where deformation occurs in steady-state regime, from the upper crust where it is rather dominated by stick-slip. The fault hangingwall above BDT accumulates elastic energy during the interseismic period, without significant evidence of surface strain rate Faults activate in areas of high strain rate gradients along the segments with lower strain rates Fluid discharge varies as a function of the tectonic setting The phenomenology gives insights for the parameters to be monitored in earthquake forecasting