open access

https://hdl.handle.net/2115/65174

Crustal magma pathway beneath Aso caldera inferred from three-dimensional electrical resistivity structure

英語

2016-10-28

American Geophysical Union

Geophysical Research Letters

43(20)

10,720-10,727

At Naka-dake cone, Aso caldera, Japan, volcanic activity is raised cyclically, an example of which was a phreatomagmatic eruption in September 2015. Using a three-dimensional model of electrical resistivity, we identify a magma pathway from a series of northward dipping conductive anomalies in the upper crust beneath the caldera. Our resistivity model was created from magnetotelluric measurements conducted in November–December 2015; thus, it provides the latest information about magma reservoir geometry beneath the caldera. The center of the conductive anomalies shifts from the north of Naka-dake at depths >10 km toward Naka-dake, along with a decrease in anomaly depths. The melt fraction is estimated at 13–15% at ~2 km depth. Moreover, these anomalies are spatially correlated with the locations of earthquake clusters, which are distributed within resistive blocks on the conductive anomalies in the northwest of Naka-dake but distributed at the resistive sides of resistivity boundaries in the northeast.

学術雑誌論文

Version of Record

An edited version of this paper was published by AGU. Copyright 2016 American Geophysical Union. Hata, M., S. Takakura, N. Matsushima, T. Hashimoto, and M. Utsugi, (2016), Crustal magma pathway beneath Asocaldera inferred from three-dimensional electrical resistivity structure, Geophys. Res. Lett., 43, 10,720–10,727, doi:10.1002/2016GL070315. To view the published open abstract, go to http://dx.doi.org and enter the DOI.

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