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Cs in seabed sediments around the river mouth near Fukushima Daiichi Nuclear Power PlantTsuruta, Tadahiko; Harada, Hisaya*; Misono, Toshiharu; Matsuoka, Toshiyuki; Hodotsuka, Yasuyuki*
Journal of Oceanography, 73(5), p.547 - 558, 2017/10
Times Cited Count：11 Percentile：44.33(Oceanography)The seafloor topography was divided into flat and terrace seafloors based on their topographical features and seabed sediments were distributed in an area that was half a degree of the entire investigation area. The Cs inventory was several tens of kBq/m
and the grain sizes (the D50 values) were nearly constant (fine sand) on the flat seafloor. On the terrace seafloor, the Cs inventory was larger than that on the flat seafloor, and the grain size varied from silt to coarse sand. The grain size distributions appear to be influenced by the mean shear stress at the seafloor bottom, and a significant factor in the mean shear stress is thought to be the seafloor topography. Distributions of remarkably large Cs inventories, more than several thousands of kBq/m, are thought to be confined to a small area. Vertical changes in the Cs inventories suggested that the Cs inventories have significantly decreased in large areas of the shallow sea.
Matsuoka, Toshiyuki; Hodotsuka, Yasuyuki*; Yamada, Nobuto
JAEA-Research 2012-028, 70 Pages, 2012/11
JAEA-Research-2012-028.pdf:19.33MB
Reverse Vertical Seismic Profiling (R-VSP) using vibration during the construction of underground facility has been carried out at the MIU construction site to develop the technique that estimate the 3-dimensional geological structure. In this report, we apply plural data processing/analysis methods (VSP-CDP transform, VSP migration, IP transform and seismic interferometory) to observed vibration data (blasting data, drilling vibration data and construction noise data), and discuses the applicability of the R-VSP. In this study, geological structures such as unconformities between sedimentary rocks and granite, and steep faults were extracted using applied prual data processing/analysis methods. We conclude that it is likely that the R-VSP using various vibration data and prual data processing/analysis, can apply to estimate the 3-dimensional geological structure.
Tokuyasu, Shingo; Matsuoka, Toshiyuki; Hodotsuka, Yasuyuki*
JAEA-Research 2012-007, 55 Pages, 2012/06
JAEA-Research-2012-007.pdf:35.8MB
JAEA-Research-2012-007-appendix(DVD-ROM).zip:951.94MB
During drilling the pilot boring in October 2008 before construction of -300 m Access/Research Gallery, groundwater inflow more than 1,000 L/min is induced, and original signals of SP monitoring are observed. First of all in this study, we thus assess the method of data processing to extract the applicable signal from SP monitoring, and the hydrogeological structure is estimated using the treated data. Secondly, the signals of SP monitoring observed between March and April in 2006 when pumping of groundwater from the shafts are applied to the same method of data processing mentioned above. In addition, the treated data is used to estimate the hydrogeological structures more in detail. Considering all results together, the applicability of SP monitoring for estimating the distributions of major water-conducting features and faults with low permeability is discussed. As the result of this study, we conclude that it is likely that the hydrogeological structures would be estimated using the SP monitoring.
Tsuruta, Tadahiko; Matsuoka, Toshiyuki; Hodotsuka, Yasuyuki; Tagami, Masahiko; Ishida, Hideaki; Hayano, Akira; Kurihara, Arata; Yuguchi, Takashi
JAEA-Research 2010-039, 131 Pages, 2011/01
JAEA-Research-2010-039.pdf:25.36MB
Tono Geoscientific Unit of Geological Isolation and Development Directoratte is performing Mizunami Underground Research Laboratory (MIU) Project, which is a broad scientific study of the deep geological environment as a basis of research and development for geological disposal of nuclear wastes, in order to establish comprehensive techniques for the investigation, analysis and assessment of the deep geological environment in fractured crystalline rock. The MIU Project has three overlapping 3 phases, with a total duration of 20 years. The project goals of the MIU Project from Phase I through to Phase III are: to establish techniques for investigation, analysis and assessment of the deep geological environment, and to develop a range of engineering for deep underground application. Currently, the project is under the Phase II. This document presents the overview of results of the research and development on "geology" performed in fiscal year 2008, with regard to the Phase II goal.
Hodotsuka, Yasuyuki; Matsuoka, Toshiyuki; Tsuruta, Tadahiko; Yamada, Nobuto*; Ishigaki, Koichi*; Yamaguchi, Shinji*
Shadan Hojin Butsuri Tansa Gakkai Dai-119-Kai (Heisei-20-Nendo Shuki) Gakujutsu Koenkai Koen Rombunshu, p.61 - 64, 2008/10
Seismic interferometry using the vibration under the construction works such as borehole drilling, mucking, blasting etc., had been carried out to develop the method that obtain three-dimensional geological image, around the Mizunami Underground Research Laboratory. In this study, we discussed the applicability of this method analytical accuracy depending on vibration resource types.
Matsuoka, Toshiyuki; Hodotsuka, Yasuyuki; Tsuruta, Tadahiko; Ishigaki, Koichi*; Yamada, Nobuto*; Yamaguchi, Shinji*
Shadan Hojin Butsuri Tansa Gakkai Dai-119-Kai (Heisei-20-Nendo Shuki) Gakujutsu Koenkai Koen Rombunshu, p.65 - 67, 2008/10
A reverse VSP (R-VSP) using the blasting vibration been carried out to obtain three-dimensional geological image around the Mizunami Underground Research Laboratory under the shaft excavation works. In this study, the applicability of this method was discussed.
Hodotsuka, Yasuyuki; Matsuoka, Toshiyuki; Ishigaki, Koichi*
Nihon Oyo Chishitsu Gakkai Heisei-19-Nendo Kenkyu Happyokai Koen Rombunshu, p.213 - 214, 2007/10
no abstracts in English
Yamada, Nobuto*; Ishigaki, Koichi*; Yamaguchi, Shinji*; Narita, Norifumi*; Matsuoka, Toshiyuki; Hodotsuka, Yasuyuki; Matsuoka, Toshifumi*
Shadan Hojin Butsuri Tansa Gakkai Dai-117-Kai (Heisei-19-Nendo Shuki) Gakujutsu Koenkai Koen Rombunshu, p.146 - 148, 2007/10
Seismic interferometry synthesizes the Green's function between two receivers by calculating cross-correlation of records measured at their locations. In Japan Atomic Energy Agency(JAEA), Seismic Interferometry using blasting vibration caused by the shafts excavation had been carried out to investigate the geologic structure in the surrounding area. The result was identical to the existing seismic reflection section. In this study, we applied this technique to long time measured microtremor. The result was also identical to the results of existing section and seismic interferometry using blasting vibration caused by the shafts excavation.
Kurihara, Arata; Tsuruta, Tadahiko; Matsuoka, Toshiyuki; Hayano, Akira; Hayakawa, Masashi; Tagami, Masahiko; Hodotsuka, Yasuyuki; Yuguchi, Takashi; Ochi, Minoru; Tokuyasu, Shingo
no journal, ,
no abstracts in English
Tsuruta, Tadahiko; Amano, Kenji; Matsuoka, Toshiyuki; Tagami, Masahiko; Hodotsuka, Yasuyuki; Hayakawa, Masashi; Kurihara, Arata; Hayano, Akira; Yuguchi, Takashi
no journal, ,
no abstracts in English
Matsuoka, Toshiyuki; Amano, Kenji; Tsuruta, Tadahiko; Abumi, Kensho; Hodotsuka, Yasuyuki
no journal, ,
no abstracts in English
Matsuoka, Toshiyuki; Hodotsuka, Yasuyuki; Ishigaki, Koichi*; Lee, C. H.*
no journal, ,
We carried out R-VSP using vibrations caused by blasting for the shaft excavation and drilling of the borehole investigation in the horizontal research galleries of the MIU, and examined the applicability of this method to imaging of geological structures around underground facilities, such as boundary between sedimentaly rocks and basal granite, fault and fracture zone in basal granite. As the results, the reflective events that seemed to correspond with sedimentary layers, the unconformity between sedimentaly rocks and granite, and fracture zone in granite could be confirmed by reflection profiles using the conventional VSP data processing and Seismic interferometry. From data processing by Image Point transform, the distribution of three faults, that are correspondent with the current geological model constructed from investigation data in the MIU project, could be detected.
Hodotsuka, Yasuyuki; Matsuoka, Toshiyuki; Tokuyasu, Shingo
no journal, ,
Seismic interferometry is an investigation method used to deduce geological structures in the subsurface, by performing cross-correlations between the traces of each record and synthesizing similar data obtained by reflection seismic surveying on surface. In this study, Seismic interferometry using the vibration under the construction works, such as borehole drilling and mucking, etc. at the horizontal tunnel in the Mizunami Underground Research Laboratory, had been carried out to develop the method that obtain seismic image. The reflection image obtained from seismic interferometry using deconvolution has a high signal to noise (S/N) ratio compared to reflection images from normal seismic interferometry.
Amano, Kenji; Tsuruta, Tadahiko; Matsuoka, Toshiyuki; Abumi, Kensho; Hodotsuka, Yasuyuki
no journal, ,
no abstracts in English
