• 3-D electrical resistivity structure based on geomagnetic transfer functions exploring the features of arc magmatism beneath Kyushu, Southwest Japan Arc

Hata, Maki

Uyeshima, Makoto

Handa, Shun

Shimoizumi, Masashi

Tanaka, Yoshikazu

Hashimoto, Takeshi

Kagiyama, Tsuneomi

Utada, Hisashi

Munekane, Hiroshi

Ichiki, Masahiro

Fuji-ta, Kiyoshi

    • Copyright 2016 American Geophysical Union.
  • NDC 450
  • Our 3-D electrical resistivity model clearly detects particular subsurface features for magmatism associated with subduction of the Philippine Sea Plate (PSP) in three regions: a southern and a northern volcanic region, and a nonvolcanic region on the island of Kyushu. We apply 3-D inversion analyses for geomagnetic transfer function data of a short-period band, in combination with results of a previous 3-D model that was determined by using Network-Magnetotelluric response function data of a longer-period band as an initial model in the present inversion to improve resolution at shallow depths; specifically, a two-stage inversion is used instead of a joint inversion. In contrast to the previous model, the presented model clearly reveals a conductive block on the back-arc side of Kirishima volcano at shallow depths of ~50 km; the block is associated with hydrothermal fluids and hydrothermal alteration zones related to the formation of epithermal gold deposits. A second feature revealed by the model is another conductive block regarded as upwelling fluids, extending from the upper surface of the PSP in the mantle under Kirishima volcano in the southern volcanic region. Third, a resistive crustal layer, which confines the conductive block in the mantle, is distributed beneath the nonvolcanic region. Fourth, our model reveals a significant resistive block, which extends below the continental Moho at the fore-arc side of the volcanic front and extends into the nonvolcanic region in central Kyushu.
PublisherAmerican Geophysical Union
Date Issued 2017-01-17
NIItypejournal article
Identifier URI
  • isIdenticalTo DOI
    • ISSN 2169-9313
    • Journal of Geophysical Research: Solid Earth
    122(1), 172-190