A5059833233- Methane Hydrates and Related Phenomena
- Geology and Paleoclimatology Research
- Hydrocarbon exploration and reservoir analysis
- Geological and Geophysical Studies
- earthquake and tectonic studies
- Offshore Engineering and Technologies
- Drilling and Well Engineering
- Seismic Imaging and Inversion Techniques
- Geological formations and processes
- Landslides and related hazards
- Reservoir Engineering and Simulation Methods
- Hydraulic Fracturing and Reservoir Analysis
- CO2 Sequestration and Geologic Interactions
- Atmospheric and Environmental Gas Dynamics
- Arctic and Antarctic ice dynamics
- Coal Properties and Utilization
- Coal and Its By-products
- Urban and spatial planning
- Microbial Community Ecology and Physiology
- Fluid Dynamics Simulations and Interactions
- Soil and Unsaturated Flow
- Spacecraft and Cryogenic Technologies
- Marine Biology and Ecology Research
- Underwater Vehicles and Communication Systems
- Species Distribution and Climate Change
Geological Survey of Japan
2011-2024
National Institute of Advanced Industrial Science and Technology
2011-2024
Japan Agency for Marine-Earth Science and Technology
2007-2016
Japan Organization for Metals and Energy Security (Japan)
2011
Eneos (Japan)
2011
National Taiwan University
2009
National Central University
2009
The University of Tokyo
1998
Microbial life inhabits deeply buried marine sediments, but the extent of this vast ecosystem remains poorly constrained. Here we provide evidence for existence microbial communities in ~40° to 60°C sediment associated with lignite coal beds at ~1.5 2.5 km below seafloor Pacific Ocean off Japan. methanogenesis was indicated by isotopic compositions methane and carbon dioxide, biomarkers, cultivation data, gas compositions. Concentrations indigenous cells 1.5 ranged from <10 ~10(4) cm(-3)....
Scientific drilling at a submarine mud volcano shows that geofluid migration stimulates methanogenesis in the deep biosphere.
The bulk composition of the continental crust throughout geological history is thought by most previous workers to be andesitic. This assumption an andesitic led early hypothesis Taylor (1967 ) that was created arc magmatism. for origin challenged several authors because: (i) mean rate addition obtained Reymer and Schubert (1984 too small account some certain phases rapid crustal growth; (ii) ocean island arcs, main contributor Archean Proterozoic crust, basaltic rather than ( Arculus 1981 ;...
Abstract Natural gas hydrates (or methane hydrates) could become a major energy source but also exacerbate global warming, because as the climate warms, hydrate deposits deep under oceans or in permafrost may release into atmosphere. There are many shallow of fine‐grained muddy sediments on seafloor. However, mechanical properties these have not yet been investigated engineering challenges coring and testing at situ temperatures pressures. Here we present first uniaxial triaxial strength...
Physical properties (bulk density and porosity) thermal (thermal conductivity, heat capacity, specific heat, diffusivity) of sediment are crucial parameters for basin modeling. We measured these physical mud-dominant recovered from the Joetsu Basin, in eastern margin Japan Sea. To determine diffusivity, dual-needle probe method was applied. Grain grain were estimated by applying existing models sediment. suggest that density, diffusivity depend on mineral composition. Conversely, capacity...
Multi-scale reflection seismic data, from deep-penetration to high-resolution, have been analyzed and integrated with near-surface geophysical geochemical data investigate the structures gas hydrate system of Formosa Ridge offshore southwestern Taiwan. In 2007, dense large chemosynthetic communities were discovered on top at water depth 1125 m by ROV Hyper-Dolphin. A continuous strong BSR has observed profiles 300 500 ms two-way-travel-time below seafloor this ridge. Sedimentary strata are...
This study reveals the hydrocarbon generation potential and thermal maturity of coal coaly mudstones from Eocene Urahoro Group in Kushiro basin (Kushiro Basin) eastern Hokkaido (Japan). The is classified as subbituminous or high volatile C bituminous, characterized by hydrogen content (6.1 ± 0.4 wt%, 1σ, dry ash free basis). index (HI = 180–409 mg hydrocarbon/g total organic carbon) random mean vitrinite reflectance (VRr 0.42–0.56%) indicate that are gas- oil-prone oil-prone. Based on HI VRr...
The results of a three-dimensional seismic survey the continental slope off Shimokita Peninsula, NE Japan, reveal detailed features typical slumps and related fluid-migration paths in Pliocene Quaternary formations. Dewatering structures, which are strongly dependent on development imbricate structures within slump sediments, acted to drain excess fluid that accumulated upon slip planes slumping. Damped dimmed reflections dewatering indicate distribution natural gas is circulation around...
A high-resolution seismic reflection survey was conducted over submarine mounds on continental slope ridges in passive margin offshore southwestern Taiwan during the NT07-05 cruise March 2007. The were formed by an erosion system which canyons incise and control ridge formations. revealed geologic structure of where there are target locations, site F G, mounds. Site corresponds to southern peak Formosa Ridge, sedimentary strata generally flat lying. On methane hydrate BSR (bottom simulating...
Abstract Understanding of fluid behavior and gas distribution in the shallow subsurface are important considerations hydrate formation global carbon cycle. Estimation based on reflection seismic surveys, however, is difficult because boundary a gas‐bearing zone indistinct not systematically defined. This study reports distinctive features related to gas‐hydrate possible migration high‐resolution 3 D seismic‐reflection data from sediments eastern N ankai T rough. These features, here termed...
High resolution 3D seismic survey “Tokai-oki to Kumano-nada” was conducted for methane hydrate exploration in the eastern Nankai Trough by METI 2002. Our study focuses on zigzag-shaped specific reflectors which occur BSR margins data. We call “Foldback Reflectors (FBRs)” this study. From edge of BSR, 1st FBR generally extends down lower formation below and cross sedimentary horizons. The following FBRs extend from upper forming accordion-like shape. indicates normal polarity, change their...
Abstract Accurate surface heat flow data are required for a wide range of geological and geophysical applications. However, sediment temperature measurements beneath the seafloor often involve large uncertainties owing to influence bottom-water (BWT) fluctuations. Previous studies reported apparently negative geothermal gradients in Joetsu Basin Japan Sea suggested that BWT fluctuations disturbed temperatures. To address this problem, we monitored BWTs over 2 year period determine depth at...
High resolution 3D seismic survey, “Tokai-oki to Kumano-nada”, was conducted for methane hydrate exploration in the eastern Nankai Trough by METI 2002. Our study focuses on zigzag-shaped specific reflectors BSR margins data. We call “Foldback Reflectors (FBRs)” this study. From edge of BSR, 1st FBR generally extends down lower formation below crossing sedimentary horizons. The following FBRs (often 2nd, sometimes 3rd and those higher order) extend from upper forming accordion-like shape....