Abstract
AbstractMany active volcanoes and various types of seismic activities exist in the southern part of the Northeast Japan subduction zone. One of the geologically most interesting features in this area is the sequential explosive eruptions of a group of volcanoes. The group consists of Mt. Azuma and Mt. Adatara on the volcanic front line, Mt. Bandai west of the volcanic front, and Mt. Numazawa on the back-arc side. A previous petrological study on the eruption products regarded Mt. Numazawa as an anomalous back-arc volcano because its lavas are similar to those of volcanoes on the volcanic front. The reason behind this unique connection was unclear, and hence, this study was intended to understand the deep fluids distribution beneath the area. For this purpose, a 3-D regional electrical resistivity structure was estimated from a series of wide-band magnetotelluric surveys, with 45 observation points deployed from the fore-arc to the back-arc sides. The most important feature of the resistivity structure is a large conductive zone in the central part of the area, spanning from the upper mantle to the lower crust. Interestingly, the lateral elongation of the conductor is oblique to the volcanic front line and consistent with the spatial distribution of the group of volcanoes and the low-frequency earthquake clusters around them. Therefore, the conductor most likely represents a large, elongated magmatic fluid reservoir beneath the volcanoes. Hydrous partial melting might be the cause of the enhanced conductivity.
Graphical Abstract
Funder
Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan
Japan Society for the Promotion of Science
Earthquake Research Institute, the University of Tokyo
Lembaga Pengelola Dana Pendidikan
Japan Science and Technology Agency
Publisher
Springer Science and Business Media LLC
Subject
Space and Planetary Science,Geology
Reference36 articles.
1. Asamori K, Umeda K, Ninomiya A, Negi T (2011) Manifestations of upwelling mantle flow on the Earth’s surface. In: Phillips JM (ed) the earth’s core: structure, properties, and dynamics. Nova Science Publishers Inc, New York, pp 79–94
2. Caldwell TG, Bibby HM, Brown C (2004) The magnetotelluric phase tensor. Geophys J Int 158:457–469. https://doi.org/10.1111/j.1365-246X.2004.02281.x
3. Campanyà J, Ogaya X, Jones AG et al (2016) The advantages of complementing MT profiles in 3-D environments with geomagnetic transfer function and interstation horizontal magnetic field transfer function data: results from a synthetic case study. Geophys J Int 207:1818–1836. https://doi.org/10.1093/gji/ggw357
4. Chave AD, Jones AG (2012) The magnetotelluric method: theory and practice. Cambridge University Press, Cambridge. https://doi.org/10.1017/CBO9781139020138
5. Chave AD, Thomson DJ (2004) Bounded influence magnetotelluric response function estimation. Geophys J Int 157:988–1006. https://doi.org/10.1111/j.1365-246X.2004.02203.x
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