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Sueoka, Shigeru; Komatsu, Tetsuya; Hiura, Yuki
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no abstracts in English
Nagata, Mitsuhiro; Fukuda, Shoma; Sueoka, Shigeru; Yokoyama, Tatsunori; Kagami, Saya; Niki, Sota*; Iwano, Hideki*; Danhara, Toru*; Ogita, Yasuhiro; Kajita, Yuya*; et al.
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no abstracts in English
Niwa, Masakazu; Shimada, Koji; Watanabe, Tsuyoshi; Goto, Akira; Hiratsuka, Shinya
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As a case study to visualize crustal deformation induced by concealed faults and related structures, we applied integrated approaches of geodesy, geomorphology, and geology to a high-strain shear zone in southern Kyushu, Japan. Our GNSS observation for recent 4.7 years by a network composed of 10 stations revealed that locking depth and slip velocity of the deeper extension of the fault were estimated to be 8 km and left-lateral slip of 9 mm/year. In the geomorphological approach, concentration of E-W trend lineaments is identified in northwestern Kagoshima, near the center of the sinistral high-strain shear zone detected by the GNSS observation. The field survey showed that minor faults are common in the study area. Thus, we analyzed stress field estimated from slip data of the minor faults, and compared it with the stress field corresponding to the sinistral high-strain shear zone. The result of the analysis suggests that the subsurface deformation due to the sinistral high-strain shear zone is localized rather than dispersed.
Bateman, K.; Amano, Yuki; Tachi, Yukio
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Ogata, Manabu; King, G. E.*; Herman, F.*; Sueoka, Shigeru; Yamada, Ryuji*; Omura, Kentaro*
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no abstracts in English
Hiura, Yuki; Kawamura, Makoto; Umeda, Koji*; Niwa, Masakazu
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One of the technical issues related to volcanic and igneous activities is the sophistication of technology for grasping the range of influence of magma. To address this issue, it is important to accumulate survey cases, especially when the dike develops over a radius of 15 km from the center of the Quaternary volcano, but it lies beneath the existing volcanic body. It is practically difficult to grasp the distribution of the conduits and the dikes derived from them. Therefore, the purpose of this study was to develop a method for estimating the distribution range of dikes distributed under the Quaternary volcanic body based on topographical data such as digital elevation models. In this study, we used digital maps and GIS software to target six volcanoes, such as stratovolcanoes and calderas. The parameters were measured, and modeling of the three-dimensional distribution range of radial dikes was examined from each parameter for each altitude. As a result, the transition of the center of gravity position for each altitude suggests the transition of the center of activity in the process of forming the volcanic body to some extent, and it is possible to extract not only the activity of the central crater but also the activity of lateral volcanoes. This suggests the possibility of quantitative evaluation of the transition and stability of the conduit even in volcanoes whose activity history is not clear by applying this method.
Watanabe, Tsuyoshi; Asamori, Koichi; Shimada, Akiomi; Saiga, Atsushi; Ogawa, Hiroki; Umeda, Koji*; Goto, Akira; Shimada, Koji; Ishimaru, Tsuneari
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no abstracts in English
Sasao, Eiji
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It is necessary to consider the long-term supply to utilize nuclear power stably. Information on uranium resources is periodically reported by international and national organizations. In this presentation, supply and demand of uranium are reviewed based mainly on the latest edition of "Red Book", which is periodic prepared by OECD/NEA and IAEA on world uranium resources, production and demand. Future perspective on supply of uranium from the principal supplying countries, Canada and Australia, is discussed based on the geological viewpoint.
Noda, Atsushi*; Miyazaki, Kazuhiro*; Mizuno, Kiyohide*; Nagata, Mitsuhiro
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no abstracts in English
Wakasa, Sachi*; Ishiyama, Tatsuya*; Hirouchi, Daisuke*; Matsuta, Nobuhisa*; Fujita, Natsuko; Echigo, Tomoo*
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no abstracts in English
Tomita, Yutaka; Kijima, Yuichi; Furuno, Akiko; Yamamoto, Yoichi
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The Japan Atomic Energy Agency (JAEA) has operated two radionuclide stations which are Takasaki radionuclide station (RN38) and Okinawa radionuclide station (RN37) for the CTBT (Comprehensive Nuclear- Test-Ban Treaty) International Monitoring System (IMS). RN38 was built in the Takasaki Advanced Radiation Research Institute of the National Institutes for Quantum and Radiological Science and Technology (QST) in 2002. Radioactivity of particulate radionuclides and radioxenon gases are measured at RN38 by using a Radionuclide Aerosol Sampler / Analyzer (RASA) and a Swedish Automatic Unit for Noble Gas (SAUNA) respectively. It was worthy of special mention that the SAUNA of RN38 detected the radioxenons which were related to the DPRK-3 event in 2013. RN37 was installed in a renovated facility at the Okinawa Tracking and Communication Station of the Japan Aerospace Exploration Agency (JAXA) in 2006. It measures only radioactivity of particulate radionuclides by using a RASA. JAEA contributes to the CTBT international verification regime through these activities. Operation and some monitoring results of both radionuclide stations will be reported in this presentation.
Minami, Saki*; Sueoka, Shigeru; Kohn, B. P.*; Fukuda, Shoma; Kajita, Yuya*; Ogita, Yasuhiro; Tagami, Takahiro*
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Tateishi, Ryo*; Shimada, Koji; Niwa, Masakazu; Sueoka, Shigeru; Shimizu, Mayuko; Kanno, Mizuho; Ishii, Chikako; Ishimaru, Tsuneari
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The major difference between active faults and inactive faults is the elapsed time after the latest activity, and while active faults are considered to be on the order of 
to 
years, inactive faults are over 
years. Therefore, even if the phenomena caused by fault activity are the same in both cases, the chemical changes that occur during the subsequent rest period of fault activity may differ significantly. In this study, the chemical composition of fault clay was collected by literature values and actual analysis, and the feasibility of discrimination by the chemical composition examined by linear discriminant analysis. According to the 11 elements selected based on the AIC, 45 active fault samples and 51 inactive fault samples were identified with a discrimination rate of 96%. Among the elements, TiO
and PO
tended to be concentrated as the latest activity period was newer. These concentration mechanisms are for future work.
Miyamoto, Tatsuki*; Sugai, Toshihiko*; Niwa, Yuichi*; Nakanishi, Toshimichi*; Komatsu, Tetsuya; Hiura, Yuki
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Ogita, Yasuhiro; Sando, Kazusa*; Ishibashi, Kozue*; Sakata, Shuhei*; Ono, Takeshi*; Suzuki, Satoshi*; Yokoyama, Tatsunori; Kagami, Saya; Nagata, Mitsuhiro; Yuguchi, Takashi*
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no abstracts in English
Kajita, Yuya*; Sueoka, Shigeru; Fukuda, Shoma; Yokoyama, Tatsunori; Kagami, Saya; Nagata, Mitsuhiro; Kohn, B. P.*; Tagami, Takahiro*
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no abstracts in English
Sato, Naomi; Hayano, Akira; Teshima, Minoru*; Negi, Tateyuki*; Yamane, Terumasa*; Kawasaki, Shinji*
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This paper reports the preliminary results of the magnetotelluric (MT) survey aiming to evaluate the three-dimensional distribution of fossil seawater in the Horonobe area. The MT survey was conducted in the area of 3 km square adjacent to the Horonobe Underground Research Laboratory at 60 points. Our results showed that the distribution of the resistivity varied in accordance with the geological structure. This survey was funded by the Ministry of Environment, Trade and Industry.
Chen, X.*; Chikamatsu, Kentaro*; Nagata, Mitsuhiro; Yokoyama, Tatsunori; Kagami, Saya; Yamamoto, Koshi*; Oto, Shigeru*
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no abstracts in English
Fukuda, Shoma; Sueoka, Shigeru; Kajita, Yuya*; Kagami, Saya; Yokoyama, Tatsunori; Tagami, Takahiro*
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no abstracts in English
Sasao, Eiji
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This paper will be presented as an invited talk in the session "Nuclear Geoscience in Developing Countries" at the Japan Geoscience Union Meeting 2021. In this paper, the current status of radioactive waste disposal in Japan, especially from the geoscientific point of view, is introduced. In particular, I introduce the current status of geoscientific studies, including the release of the Nationwide Map of "Scientific Features" relevant for Geological Disposal, for the implementation of geological disposal of high-level radioactive waste in Japan, located in a geologically active zone.