气候变化领域集成服务门户(CCPortal): Electrical Resistivity Structure Around the Atotsugawa Fault, Central Japan, Revealed by a New 2-D Inversion Method Combining Wideband-MT and Network-MT Data Sets

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DOI	10.1029/2020JB020904
	Electrical Resistivity Structure Around the Atotsugawa Fault, Central Japan, Revealed by a New 2-D Inversion Method Combining Wideband-MT and Network-MT Data Sets
	Usui Y.; Uyeshima M.; Ogawa T.; Yoshimura R.; Oshiman N.; Yamaguchi S.; Toh H.; Murakami H.; Aizawa K.; Tanbo T.; Ogawa Y.; Nishitani T.; Sakanaka S.; Mishina M.; Satoh H.; Goto T.-N.; Kasaya T.; Mogi T.; Yamaya Y.; Shiozaki I.; Honkura Y.
发表日期	2021
ISSN	21699313
卷号	126 期号:4
英文摘要	The Atotsugawa fault is one of the most active faults in Japan, and the strain accumulation at the fault is considered to be caused by an aseismic shear zone in the fluid-rich lower crust. To identify the shear zone and investigate the origin of the aqueous fluid in the lower crust, we deployed a Network-MT survey in addition to a conventional wideband-MT survey around the fault and performed an inversion combining both the MT data sets. In the inversion, by modifying a conventional inversion algorism, we accurately represented kilometer-scale dipoles of the Network-MT measurement to provide constraints on the electrical resistivity structure. In the lower crust under the study area, there are localized conductive anomalies below the Atotsugawa fault, the Ushikubi fault, and the Takayama-Oppara fault zone. Comparing our electrical resistivity structure with the seismic velocity structure, we interpreted that the lower-crustal conductors are localized ductile shear zones with highly connected fluid. We considered that the localized ductile shear zones are responsible for the strain accumulation along the respective active faults. In addition, in the mantle wedge above the subducting Philippine Sea slab and its downward extension, a highly conductive portion is detected, which may be attributed to the fluid dehydrated from the Philippine Sea slab and/or the Pacific slab. The existence of the large conductive area supports the suggestion of previous seismic and geochemical studies that the fluid of the lower crust around the Atotsugawa fault originated from subducting slabs. © 2021. American Geophysical Union. All Rights Reserved.
英文关键词	ductile shear zone; fault-zone conductor; lower-crustal fluid; magnetotelluric inversion; Network-MT method; upper mantle fluid
语种	英语
来源期刊	Journal of Geophysical Research: Solid Earth
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/187203
作者单位	Earthquake Research Institute, The University of Tokyo, Tokyo, Japan; Disaster Prevention Research Institute, Kyoto University, Kyoto, Japan; Faculty of Science, Osaka City University, Osaka, Japan; Graduate School of Science, Kyoto University, Kyoto, Japan; Faculty of Science and Technology, Kochi University, Kochi, Japan; Faculty of Science, Institute of Seismology and Volcanology, Kyushu University, Fukuoka, Japan; Tateyama Caldera Sabo Museum, Toyama, Japan; Volcanic Fluid Research Center, Tokyo Institute of Technology, Tokyo, Japan; Faculty of Engineering and Resource Science, Akita University, Akita, Japan; Graduate School of Science, Tohoku UniversityMiyagi, Japan; Nuclear Regulation Department, Nuclear Regulation Authority, Tokyo, Japan; Graduate School of Life Science, University of Hyogo, Hyogo, Japan; Research and Development Center for Earthquake and Tsunami, Japan Agency for Marine-Earth Science and Technology, Yokosuka, Japan; Next-Generation Technology for Ocean Resources Exploration Projec...
推荐引用方式 GB/T 7714	Usui Y.,Uyeshima M.,Ogawa T.,et al. Electrical Resistivity Structure Around the Atotsugawa Fault, Central Japan, Revealed by a New 2-D Inversion Method Combining Wideband-MT and Network-MT Data Sets[J],2021,126(4).
APA	Usui Y..,Uyeshima M..,Ogawa T..,Yoshimura R..,Oshiman N..,...&Honkura Y..(2021).Electrical Resistivity Structure Around the Atotsugawa Fault, Central Japan, Revealed by a New 2-D Inversion Method Combining Wideband-MT and Network-MT Data Sets.Journal of Geophysical Research: Solid Earth,126(4).
MLA	Usui Y.,et al."Electrical Resistivity Structure Around the Atotsugawa Fault, Central Japan, Revealed by a New 2-D Inversion Method Combining Wideband-MT and Network-MT Data Sets".Journal of Geophysical Research: Solid Earth 126.4(2021).