Publication Date:
2023-07-19
Description:
Resistivity is a physical parameter sensitive to the existence and connectivity of the crustal fluids and melts. In this paper, we present a 3-D resistivity model covering an area of 50km x 50km in the central part of the NE Japan volcanic arc. We have compiled wide-band magnetotelluric data, which were collected over 30 years. We used full impedances and tippers of the 410 stations between 0.4 and 1,300s periods. The final model shows the existence of a continuous low resistivity belt in the SSW-NNE direction along the volcanic arc in the deep crust (20 km to 30 km depth). On the forearc side, we also see a distribution of low resistivity anomalies, which imply fluid upwelling. These low resistivity anomalies in the deep crust correspond to strain-concentration areas along the volcanic arc and the forearc. The low resistivity zone along the volcanic arc locally shallows to a depth of 10 km, branching toward active quaternary volcanoes, such as Naruko volcano, Mt. Kurikoma, Onikobe caldera, and Takamatsu-dake. These swallow anomalies below the volcanoes imply magmatic melt and correlate well with the co-seismic subsidence zones due to "2011 off the Pacific coast of Tohoku earthquake" detected by InSAR.
Language:
English
Type:
info:eu-repo/semantics/conferenceObject
