Nankai Trough fault slip behavior analyzed in-situ and in shear experiments

Abstract

The Nankai Trough subduction zone hosts various modes of fault slip from slow to megathrust earthquakes. Slow earthquakes release energy slowly over days to years and can only be recorded geodetically or by borehole observatories. It is not well understood how they connect to regular earthquakes. In contrast, megathrust earthquakes are rapid events that often generate destructive tsunamis, documented for several centuries in the Nankai Trough. Successful earthquake mitigation strategies can only be developed with a better understanding of fault slip behavior and deformation processes within the seismogenic zone and the overlying accretionary prism.