Multiple Linear Array Microtremor Measurement Across the Nagao Fault

We performed 18 linear arrays using 6 recorders simultaneously with high-sensitivity seismometer along the survey line which crosses an active fault, Nagao fault in Kagawa Prefecture, Japan. The survey line was set as the same line with that the seismic reflection survey have been conducted. We computed H/V, single-station cross-correlation and phase velocity using cross-correlation by zero-crossing method. The contour map of H/V shows significant variation of peak frequency at the expected fault location. The single-station cross-correlation and phase velocity also showed a variation at the fault location. It suggests a potential for the use of microtremors for the exploration of fault location with low-cost than seismic survey method.