[SEM16-P02] MAGNETOTELLURIC TRANSECT OF THE UNZEN GRABEN
Keywords:Graben, Conduit, Faults, Resistivity, Magnetotelluric, 3D structure
In April-May 2017, we installed 4 magnetotelluric and 23 telluric stations along approximately 9 km N-S trending survey line with distance between each station is 300 m-400m. Then, we recorded the electromagnetic field variations approximately for one week. Resistivity model by 2-D inversion shows good coincidence with the seismic reflection profile. In this case, high resistivity zone is correlated with low reflection zone in the possible conduit region. However this correspondence should be carefully investigated, because the phase tensors (Caldwell et al., 2004) and induction vectors behaviour indicate 3-D structure in the deeper region. We will conduct 3-D inversion to confirm the relationship between electrical resistivity and seismic reflection, and discuss the physical property of structure beneath Unzen graben.