Refine your search:     
Report No.
 - 
Search Results: Records 1-14 displayed on this page of 14
  • 1

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

Journal Articles

Horizontal and vertical distributions of $$^{137}$$Cs in seabed sediments around the river mouth near Fukushima Daiichi Nuclear Power Plant

Tsuruta, Tadahiko; Harada, Hisaya*; Misono, Toshiharu; Matsuoka, Toshiyuki; Hodotsuka, Yasuyuki*

Journal of Oceanography, 73(5), p.547 - 558, 2017/10

 Times Cited Count:10 Percentile:55.23(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 $$^{137}$$Cs inventory was several tens of kBq/m$$^{2}$$ and the grain sizes (the D50 values) were nearly constant (fine sand) on the flat seafloor. On the terrace seafloor, the $$^{137}$$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 $$^{137}$$Cs inventories, more than several thousands of kBq/m$$^{2}$$, are thought to be confined to a small area. Vertical changes in the $$^{137}$$Cs inventories suggested that the $$^{137}$$Cs inventories have significantly decreased in large areas of the shallow sea.

JAEA Reports

Reverse Vertical Seismic Profiling using vibration during the construction of underground facility

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.

JAEA Reports

Studies on estimation of hydrogeological structure using self-potential monitoring around Mizunami Underground Research Laboratory (MIU)

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.

JAEA Reports

Study on Geology on Mizunami Underground Research Laboratory Project; Annual report for fiscal year 2008

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.

Journal Articles

Development of geophysical survey technique using the vibration caused by the shafts excavation in the granite; Application of seismic interferometry

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.

Journal Articles

Development of geophysical survey technique using the vibration caused by the shafts excavation in the granite; Application of reverse VSP

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.

Journal Articles

Geological structure survey using the vibration caused by the shafts excavation

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

Journal Articles

Seismic interferometry using long time measured microtremor

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.

Oral presentation

Overview of the final report on the surface-based investigation (Phase I) at the Mizunami Underground Laboratory project, 2; Geological and geophysical studies

Amano, Kenji; Tsuruta, Tadahiko; Matsuoka, Toshiyuki; Abumi, Kensho; Hodotsuka, Yasuyuki

no journal, , 

no abstracts in English

Oral presentation

Overview of the surface-based investigation phase (Phase I) at the Mizunami Underground Laboratory project, 2; Geological and geophysical studies

Matsuoka, Toshiyuki; Amano, Kenji; Tsuruta, Tadahiko; Abumi, Kensho; Hodotsuka, Yasuyuki

no journal, , 

no abstracts in English

Oral presentation

Mizunami URL project, geological investigations

Tsuruta, Tadahiko; Amano, Kenji; Matsuoka, Toshiyuki; Tagami, Masahiko; Hodotsuka, Yasuyuki; Hayakawa, Masashi; Kurihara, Arata; Hayano, Akira; Yuguchi, Takashi

no journal, , 

no abstracts in English

Oral presentation

3D imaging of geological structure by R-VSP utilizing vibrations caused by shaft excavation at the Mizunami Underground Research Laboratory in Japan

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.

Oral presentation

Application of seismic interferometry using the vibration caused by the shafts excavation in the granite

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.

Oral presentation

Mizunami Underground Laboratory project; Investigation of geology

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

14 (Records 1-14 displayed on this page)
  • 1