@article{0f07b5a6d05648b583da08055936674e,
title = "Resistivity structure of high-angle subduction zone in the southern Kyushu district, southwestern Japan",
abstract = "Magnetotelluric observations were carried out in the southern Kyushu district of southwestern Japan to investigate the characteristics of the electrical resistivity structure of a high-angle subduction zone. We constructed a 2-D resistivity model parallel to the subducting plate motion by using the inversion technique with the Akaike Bayesian Information Criterion (ABIC) smoothness constraint. The general features of the obtained resistivity structure are as follows: (1) a conductive block (below 1 Ω·m) is found beneath the volcanic zone and is widespread bilaterally below 40 km depth, (2) a resistive block (about 1000 Ω·m) distributes from 10 to 25 km depth in the forearc region and (3) a conductor (1 ˜ 30 Ω·m) is embedded beneath the resistive block, which may correspond to the negative Bouguer gravity anomaly observed in this region. We propose the following for the high-angle subduction zone: A serpentinized block is generated in the lower crust of the forearc region and a partial melting and hydrothermal fluid are well developed beneath the volcanic front.",
author = "Masahiro Ichiki and Norihiko Sumitomo and Tsuneomi Kagiyama",
note = "Funding Information: Acknowledgments. We thank H. Utada, Y. Sasai, H. Shimizu, N. Oshiman, T. Furuzawa, Y. Tanaka and T. Kakuta for their helpful comments, discussion, and critical reading of the manuscript. We also acknowledge M. Teraishi, Y. Sonoda, T. Hashimoto, F. Masu-tani, Y. Makino and K. Iwakiri for their help with the observations. We are indebted to K. Ishihara, T. Eto and H. Miyamachi for facilitating the observations. For the observation, one of the author (M. I.) was supported by the Faculty of Science, Kagoshima Univ. through the system for extramural research fellowships. A special acknowledgment goes to T. Uchida and Y. Ogawa for providing their MT-inversion programs. We also wish to thank A. Chave for providing the robust estimation program for magnetotelluric responses through the MTNET home page (http://www.cg.NRCan.gc.ca/ mt-net/progs/progs.html). The subsequent version has been greatly improved by H. Toh and H. Brasse. A reference was kindly provided by M. Shimoizumi and M. Nakada. Some of the figures were created by using GMT systems ver. 3.3.2 (Wessel and Smith, 1998). We list those who kindly allowed the observation us to use their sites for observations and for supporting, sustaining, and understanding our scientific research: the Ochiai family in Kiyotake, Miyazaki Prefecture, S. Morinaga in Saito, Miyazaki Prefecture, S. Shirakawada in Miyanojo, Kagoshima Prefecture, Fujikawa-Sanrin Co. Ltd., Kirishima-Tsuma Shrine, Miyanojo Town Office, Yokogawa Town Office, Miyazaki Prefectural Office, Miyazaki District Forestry Office and Aya District Forestry Office.",
year = "2000",
doi = "10.1186/BF03351661",
language = "English",
volume = "52",
pages = "539--548",
journal = "Earth, Planets and Space",
issn = "1343-8832",
publisher = "Terra Scientific Publishing Company",
number = "8",
}