A5079327986- Groundwater and Isotope Geochemistry
- Geology and Paleoclimatology Research
- Groundwater flow and contamination studies
- Radioactive contamination and transfer
- Nuclear Physics and Applications
- earthquake and tectonic studies
- Radioactivity and Radon Measurements
- Methane Hydrates and Related Phenomena
- Geochemistry and Geologic Mapping
- Graphite, nuclear technology, radiation studies
- Karst Systems and Hydrogeology
- Isotope Analysis in Ecology
- Geophysical Methods and Applications
- Earthquake Detection and Analysis
- Radioactive element chemistry and processing
- Hydrology and Watershed Management Studies
- Nuclear and radioactivity studies
- Cryospheric studies and observations
- Atmospheric and Environmental Gas Dynamics
- Nuclear physics research studies
- Gyrotron and Vacuum Electronics Research
- Urban and spatial planning
- Geothermal Energy Systems and Applications
- Seismic Waves and Analysis
- Flow Measurement and Analysis
National Institute of Advanced Industrial Science and Technology
2011-2022
Geological Survey of Japan
2011-2022
University of Tsukuba
2005-2022
Japan Research Institute
2017
High Energy Accelerator Research Organization
2008
Fault zones can play a critical role in controlling small to large scale groundwater flow. Extensive studies have focused on permeability variations along faults terms of conduit or barrier function for deep However, little attempt has been made characterize the hydrologic functions near-surface fault zones.When exposed atmospheric conditions, are further disturbed by stress relief and chemical weathering, modifying their structure generally increasing permeability. Consequently, zone,...
近年のHi-netによる地震観測網により,我が国の沈み込み帯における地殻・マントル中の熱水流体の不均質分布による三次元地震波速度構造の異常や深部流体に関連する深部低周波地震の存在などが明らかになってきた。地球物理学的な観測結果に基づく岩石学的水循環モデルは,固体地球内部の水収支を定量化し,滞留時間の長い深層地下水中には検出可能な濃度でスラブ脱水起源の深部流体が流入していることを示す。また,内陸地震発生における深部流体の役割も,近年重要視されている。モデルは主に地球物理学的観測やシミュレーション等の結果に基づいたものであるため,地球化学的・地質学的な物質科学的証拠の蓄積はモデルの高度化にとって重要である。そこで,我々は西南日本の中国–四国–近畿地方において深層地下水の同位体化学的特徴の検討を行い,地下水系に混入する深部流体の広域分布について明らかにした。その結果,マグマ水と似た同位体組成をもつ深部流体,すなわち,スラブ起源深部流体のLi/Cl比(重量比)が0.001より高いことを示した。Li/Cl比は,天水起源の淡水で希釈されても大きく変化しないことが期待されるため,深部流体の指標...
We propose a methodology for estimating the residence time of groundwater based on bomb‐produced 36 Cl. Water samples were collected from 28 springs and 2 flowing wells located around Mt. Fuji, Central Japan. Cl/Cl ratios in water samples, determined by accelerator mass spectrometry (AMS), between 43 × 10 −15 412 . A reference series above‐background (i.e., bomb‐derived) Cl concentration was constructed linearly scaling background‐corrected Dye‐3 data according to estimated total fallout...
Understanding the age distribution of groundwater can provide information on both recharge history as well geochemical evolution flow systems. Of few candidates available that be used to date old groundwater, 81Kr shows most promise because its input function is constant through time and there are less sources sinks complicate dating procedure in comparison traditional tracers such 36Cl 4He. In this paper we use a large basin obtain better understanding residence an unconfined-confined...
We studied the origin of deep groundwater in Joban and Hamadori areas southern Tohoku, Japan, based on δD, δ18O, 129I/I, 36Cl/Cl, 3H concentrations. Deep was collected from basement rocks (Cretaceous granite) margin sedimentary basin (latest Cretaceous to Quaternary deposited rocks). sampled pumped depths ranging 350 1,600 m these areas. A hypothetical end-member estimated relationship between δ18O Cl concentrations, our data reveal a much higher iodine concentration lower Br concentrations...
Major ion chemistry, oxygen isotope and multivariate statistical method were used to investigate aquifers interaction in the southwestern foot of Mt. Fuji, largest Quaternary stratovolcano Japan. Groundwater samples taken from different which are descending order: superficial aquifer, residing New Fuji Lava Old Aquifer. The geochemical signatures groundwaters, notably molar Na/Cl Na/Ca ratios, stable nitrate contents evolution, conjunction with hierarchical cluster analysis allowed highlight...
Current studies on the groundwater ages in Mt.Fuji are reviewed.Mt.Fuji is one of largest Quaternary stratovolcanoes Japan (volume 1,200⊖1,500 km 3 ) .The large amount precipitation mountain slopes (annual volume approximately 2 × 10 9 m suggests that contains substantial reservoirs its main body.In fact, numerous springs located around foot originate mainly from confined Holocene lava flows.Early area focused development resources, followed by measures to address problems including...
This study investigates the potential of 36Cl in tracing young groundwater with residence times up to ~50 years. Groundwater samples were obtained from 16 irrigation wells paddy fields located within an upland–lowland system Yoro River basin, Central Japan. The 36Cl/Cl ratios range 17 362 × 10−15. Among higher Cl− concentrations (>10 mg/L), two showed high nitrate as well (>30 mg/L). Except for these samples, distribution was essentially consistent previous tritium concentration data...
We investigated the influence of long-term sea-level changes on groundwater flow system a mid-latitude coastal granite area. Saline/brackish groundwaters were sampled from deep boreholes in Hiroshima area, southwestern Japan. The origin these waters is seawater (but not modern), as indicated by Br–/Cl– ratio, δD-δ18O and 3H concentration. 36Cl/Cl ratios component water are similar to present value. calculated 36Cl ages more than 40 ka, indicating that saline/brackish derived an incursion...
Abstract Brine samples from the wells in Kashio mineral spring (an “Arima-type” hot at Ooshika-Mura, central Japan) were analyzed to determine original chemical and isotopic compositions of deep brine end-member before its dilution by meteoric water elucidate origin end-member. The trends variation between Cl, δD, δ 18 O indicated existence a two-component mixing system systematic ratio, which mentioned previous studies. By carefully tracking tritium ( 3 H) atmospheric noble gas brine, Cl...
The depth profile of 36Cl/Cl ratio in groundwater was investigated the Tsukuba Upland central Japan. obtained results clearly show influence bomb-produced 36Cl; highest is about one order magnitude greater than natural background (1 × 10-13). vertical distribution 36Cl consistent with previous observations using 3H and Darcy’s law. From profile, total fallout upland 2.3 1012 atoms/m2 after correction for surface runoff (c.f. 2.4 at Dye-3 site, Greenland) a scaling factor 0.96 2.5 based on...
The evaluation of radioactivity induced in the concrete shield is important for decommissioning accelerator facilities. Specific activities gamma-ray emitters nuclear spallation products and thermal neutron capture beta-ray such as tritium 14C, 36Cl along 12-GeV proton beam line (EP1 line, High Energy Accelerator Research Organization) were determined. depth profiles each nuclide 6-m-thick lines compared, secondary particles reactions discussed.