Re-analysis of broad-band magneto-telluric data in the focal region of the 2000 Western Tottori Earthquake (Mj=7.3)

Nakamura, Kensuke*; Aizawa, Koki*; Asamori, Koichi; Oshiman, Naoto*; Shiozaki, Ichiro*; The 2001 Research Group for Crustal Resistivity structure*

We show the resistivity structure around the focal region of the 2000 Western Tottori Earthquake (M7.3). The purpose of this study is to investigate the relationship between the rupture of the mainshock and the resistivity structure. In particular, we focus on the resistivity structure around the zones where the rupture started and arrested. In previous study, 3-D resistivity structure around the focal region was determined using 52 broad-band MT sites. In addition to the 52 sites, we added 12 broad-band MT sites. We recalculate the MT response functions and used full components of the impedance tensor and geomagnetic transfer functions to image three-dimensional resistivity structure. The new points of the analysis are summarized as follows. (1) re-calculation of MT response functions. (2) using full impedance tensor and geomagnetic transfer functions in three-dimensional inversion. (3) including oceans in three-dimensional inversion.