Resistivity structure of a seismic gap along the Atotsugawa Fault, Japan

The lower crust appears as a conductive zone beneath the low-seismicity segment, less conductive beneath the high-seismicity segment. Fluid is inferred as a preferable cause of the conductive zone in this study. It is suggested that the conductive lower crust beneath the low-seismicity segment is recognized where fluid is trapped by an impermeable layer in the upper crust. On the other hand, fluid in the lower crust may upwell to the surface along the high-seismicity segment of the fault.