5-3. Study on Crustal Resistivity Structure

 

　The crustal resistivity structure is investigated in areas of high seismic and volcanic activities(Fig.1).  The results from seismically active areas indicate a relation between distribution of microearthquakes and/or deap seated active faults and crustal resistivity(Fig.2).  In volcanic areas, investigations aim to clarify the relations between ground water distribution and precursory signal generation, depth to magma source and features of volcanic eruption.

 

Fig.1 Sites of resistivity structure investigations performed by research group for resistivity structure.

 

Fig.2 2-D resistivity cross section determined by analysis of wide-band MT survey performed at active Tohoku backarc area. Also shown are seismicity data after Umino et al.(2000) (circles), S-wave reflectors (squares) & P-wave scatterers (stars) determined by Asano(1998), seismic reflection result after Hirata et al.(1999), and seismic refraction result after Iwasaki et al.(1999).