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Shimo, Michito*; Niwa, Masakazu; Miyakawa, Kazuya; Yasue, Kenichi*; Tonokura, Kenichi*; Tokunaga, Tomochika*
Fukada Chishitsu Kenkyujo Nempo, (23), p.21 - 34, 2022/00
no abstracts in English
Miyakawa, Kazuya; Shimo, Michito*; Niwa, Masakazu; Amano, Kenji; Tokunaga, Tomochika*; Tonokura, Kenichi*
Fukada Chishitsu Kenkyujo Nempo, (22), p.139 - 153, 2021/00
no abstracts in English
Shimo, Michito*; Niwa, Masakazu; Miyakawa, Kazuya; Amano, Kenji; Tonokura, Kenichi*; Tokunaga, Tomochika*
Fukada Chishitsu Kenkyujo Nempo, (22), p.119 - 137, 2021/00
no abstracts in English
Toya, Naruhisa; Takeuchi, Ryuji; Tokunaga, Tomochika*; Aichi, Masaatsu*
Proceedings of 36th International Association of Hydrogeologists Congress 2008 (IAH 2008) (CD-ROM), 7 Pages, 2008/10
Excavation of the Mizunami Underground Research Laboratory began in 2003. In 2006-2007, several boreholes were drilled from the shafts and the gallery at GL-200m. Several monitoring boreholes are located in the vicinity of the NNW striking fault. The data from groundwater pressure monitoring obtained at multiple depth intervals during the drilling activities show unique responses, which resemble deformation-induced effects. In this study, we report the possible application of using these hydraulic responses for characterizing the hydrogeological structures of the site.
Tokunaga, Tomochika*; Taniguchi, Makoto*; Shimada, Jun*; Zhang, J.*; Inaba, Kaoru; Saegusa, Hiromitsu; Iwatsuki, Teruki
JNC TY7400 2003-003, 142 Pages, 2003/05
JNC-TY7400-2003-003.pdf:6.85MB
One of the major concerns for the high-level radioactive waste disposal is the possibility of the radionuclides to reach biosphere by groundwater flow. Recent research results have shown that the fresh groundwater discharge from subsea formations are widespread phenomena, thus, it is necessary to evaluate the submarine groundwater discharge as possible pathways of contaminant discharge towards the biosphere. It is also important to unravel the groundwater flow and associated material transport at the coastal area and subsea formations. To better understand the groundwater flow processes and the submarine groundwater discharge, we have conducted the hydrological, hydrogeological, geochemical, and numerical modeling studies at the Kurobe alluvial fan and its offshore, Toyama Prefecture, Japan. In this report, the results of the following research activities are presented:1)Development and application of a method to detect the locations of the submarine groundwater discharge.2)Development and application of a method to collect uncontaminated groundwater samples from subesa formations.3)Measurements of submarine groundwater dischange fluxes by automated seepage meter.4)Hydrological and geochemical studies for groundwater flow at the coastal area.5)Geochemical studied to understand sources of fresh submarine groundwater discharge.6)Extamination of groundwater flow and submarine groundwater discharge using methane concentration and carbon isotope ratio.7)Numerical modeling studies for coastal groundwater flow system.
Shimo, Michito*; Niwa, Masakazu; Miyakawa, Kazuya; Yasue, Kenichi*; Tokunaga, Tomochika*; Tonokura, Kenichi*; Biraud, S.*
no journal, ,
Faults and fractures often create migration pathways for gases formed in the subsurface. To investigate the applicability of the trace gas measurement to geologic seep detection, we conducted a series of mobile methane concentration surveys using Cavity Ring-down Spectroscop technology. The results support that precise trace gas measurement can be one of the promising approaches to characterize migration pathways and sources of methane in the subsurface.
Shimo, Michito*; Niwa, Masakazu; Yokoi, Satoru*; Yagi, Hiroshi*; Tokunaga, Tomochika*
no journal, ,
This study focuses on the role of faults as pathways for gas migration from the deep subsurface and aims to detect trace gas seepage along these faults. For this purpose, methane concentrations near the surface across the Aosawa Fault, Yamagata Prefecture, were measured using Cavity Ring-Down Spectroscopy (CRDS). Notable increases in methane concentration were observed at anticipated fault locations on two transects across the Aosawa Fault. The measurement results suggest that the Aosawa Fault functions as a pathway for gas migration connected to deep underground methane sources, offering new perspectives on fault structures and their relation to the petroleum system in the study area.
Shimo, Michito*; Yokoi, Satoru*; Miyakawa, Kazuya; Niwa, Masakazu; Matsuoka, Toshifumi*; Tokunaga, Tomochika*
no journal, ,
In this presentation, we report several preliminary studies to detect methane seepage using a portable gas analyzer by cavity ringdown spectroscopy.
Yokoi, Satoru*; Shimo, Michito*; Niwa, Masakazu; Matsuoka, Toshifumi*; Tokunaga, Tomochika*
no journal, ,
In this study, applicability of gas concentration mapping using an on-board portable gas analyzer by cavity ring-down spectroscopy (CRDS) was shown in sedimentary basins where large fault zones could act as migration paths.
Tokunaga, Tomochika*; Kimura, Yuki*; Ijiri, Yuji*; Motoshima, Takayuki*; Kunimaru, Takanori; Takamoto, Naohiko*; Shimada, Jun*; Hosono, Kenichi*
no journal, ,
no abstracts in English
Shimo, Michito*; Niwa, Masakazu; Amano, Kenji; Tokunaga, Tomochika*; Tonokura, Kenichi*; Matsuoka, Toshifumi*; Biraud, S.*
no journal, ,
To investigate the possibility of cavity ring-down spectroscopy technology to the gas release detection from the active fault to the atmosphere, we conducted field measurements at the Atera fault area in Gifu prefecture, Japan. Based on the results, we expect that the real-time high precision gas measurement can be one of the promising approaches to locate the active faults creating paths for the deepseated fluids.
Shimo, Michito*; Niwa, Masakazu; Miyakawa, Kazuya; Tonokura, Kenichi*; Tokunaga, Tomochika*
no journal, ,
To develop a new approach to identify the fluid flow paths in the rock formation using high-precision gas concentration detection technology, we carried out the on-ground methane concentration measurement in the Horonobe area, northern Hokkaido. A set of NW-SE trending folds and faults occur through the area. Based on the findings of oil and gas seepage, the petroleum exploration survey was conducted in this area. These records suggest the existence of the fluid migration pathways around faults to reach the ground surface from an underground source. In this paper, we report the results of on-foot measurement of methane and carbon dioxide concentrations using CRDS apparatus and depict the possible migration paths around faults based on the distribution of gas seeps and geological and geophysical information reported in the existing literature.
Yokoi, Satoru*; Shimo, Michito*; Miyakawa, Kazuya; Niwa, Masakazu; Matsuoka, Toshifumi*; Tokunaga, Tomochika*
no journal, ,
In this presentation, we report methane gas seepages along an anticlinal axis in the Horonobe area, northern Hokkaido, and discuss migration paths from an underground reservoir.
Shimo, Michito*; Niwa, Masakazu; Amano, Kenji; Tokunaga, Tomochika*; Tonokura, Kenichi*; Matsuoka, Toshifumi*; Biraud, S.*
no journal, ,
Faults and associated fracture zones often provide the paths for migration of the gas, such as methane, hydrogen and helium, formed in the deep subsurface formations. In this study, we conducted the field measurement of methane gas concentration using a back-pack type portable Cavity Ring-Down Spectroscopy (CRDS) gas analyzer at the Atera fault area in Gifu prefecture. The measurement result suggests that the trace gas measurement using a CRDS technology can be one of the promising approaches to delineate the locations of the active faults creating migration paths of the deep-seated fluids.