Re-analysis of broad-band magneto-telluric data in the focal region of the 2000 Western Tottori Earthquake

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, which was not discussed in the previous study. By using the broad-band MT data, Umeda et al. (2011) imaged a deep conductive body in the middle crust to the upper mantle on the southwestern side of the mainshock rupture fault. However, they did not investigate the spatial relationship between the resistivity structure and the slip distribution. Therefore, in this re-analysis, we have spatial attention to the shape and uniqueness of the conductors. In addition to the previous broad-band MT data, we use broad-band MT data at 12 sites obtained by Universities (The 2001 Research Group for Crustal Resistivity structure, Japan, 2001). We use full components of the impedance tensor and geomagnetic transfer functions to image preliminary 3-D resistivity structure, and investigate its relationship to the slip distribution of the mainshock and also occurrence of the aftershocks.