Geophysical characterization of lava flows at Shiraito Falls near Mt. Fuji in Japan using GPR

It has been identified that New Fuji lava over Old Fuji lava form current Mt. Fuji. Although the area is known for abundant groundwater resources, it is still not well understood where groundwater actually flows. In this study, surface GPR was used to obtain geological profiles of Shiraito Falls in southwest foot of Mt. Fuji, where water falls from clinkers and voids in lava flow. Comparing with borehole data, reflections identified in GPR profile and CMP data were interpreted to those corresponding to top soil, New Fuji lava flows, and Old Fuji lava flows. On the other hand, porous and dense layers within the New Fuji lava were not clearly identified. This study demonstrated that 100 MHz GPR can be an effective tool to characterize geology at the lava flow site.