このアイテムのアクセス数: 86
このアイテムのファイル:
ファイル | 記述 | サイズ | フォーマット | |
---|---|---|---|---|
2022K-04_06.pdf | 286.12 kB | Adobe PDF | 見る/開く |
タイトル: | 阿蘇カルデラ地下のマグマシステム --MT法データおよびNetwork-MT法データによる3次元比抵抗分布-- |
その他のタイトル: | Magma supply system beneath Aso caldera --3-D resistivity distribution by MT data and Network-MT data-- |
著者: | 畑, 真紀 ![]() 上嶋, 誠 ![]() 宇津木, 充 ![]() 松島, 喜雄 ![]() |
著者名の別形: | HATA, Maki UYESHIMA, Makoto UTSUGI, Mitsuru MATSUSHIMA, Nobuo |
発行日: | May-2023 |
出版者: | 多田 訓子 |
誌名: | 海域における地震・火山災害の軽減に資する地球電磁気学的アプローチの探求 |
論文番号: | 共同研究(一般研究集会)2022K-04 |
抄録: | Aso caldera, with dimensions of 18×25 km, lies on Kyushu Island in the Southwest Japan subduction zone. The caldera was formed during 270-90 ka by a series of huge eruptions that produced hundreds of cubic kilometers of pyroclastic deposits with VEI-7. A post-caldera cone of Naka-dake in Aso caldera is a quite active volcano, at which magmatic and phreatomagmatic eruptions occurred during 2014-2016, ash emissions continued from July 2019 to June 2020, and a phreatic eruption occurred in October 2021. In and around Aso caldera, we carried out magnetotelluric (MT) and network-MT surveys during 2015-2016 and 2019-2022, respectively. Network-MT surveys/method based on MT method, whereas the electric potential differences of the ground are measured by using long metallic wires/dipoles (~10 km) of communication lines of the commercial telephone company. In addition, the other network-MT surveys were previously carried out in Aso caldera during 1993-1998 [e.g., Hata et al., 2015]. For clarifying magma supply system beneath Aso caldera in a crustal depth scale, we determined three-dimensional (3-D) electrical resistivity models through inversion analysis of the respective MT and network-MT data sets. Here, period ranges of the MT and network-MT data sets were adopted for 0.005-2, 380 s and 30-20, 480 s, respectively. Moreover, we used a data-space inversion code, which can deal with the length and direction of each dipole [e.g., Siripunvaraporn et al., 2004], in the inversion analysis of the network-MT data. Consequently, 3-D electrical resistivity models similarly imaged the following magma supply system as low resistivity anomalies beneath Aso caldera; a significant low resistivity anomaly of northward dipping in the upper crust and the absence of a large distinctive anomaly in the lower crust [e.g., Hata et al., 2016; 2018]. The northward dipping anomaly is considered a magma pathway/reservoir which feeds magma to Naka-dake eruptions. |
記述: | 令和4年度 Conductivity Anomaly研究会 日時:令和4年12月26日(月)09:25-18:30, 12月27日(火)09:00-16:30 場所:京都大学防災研究所連携研究棟3階301号室およびZoom |
URI: | http://hdl.handle.net/2433/285655 |
関連リンク: | http://www.eqh.dpri.kyoto-u.ac.jp/CA/CA2022WS.html |
出現コレクション: | 海域における地震・火山災害の軽減に資する地球電磁気学的アプローチの探求 |

このリポジトリに保管されているアイテムはすべて著作権により保護されています。