A5076674036- Geophysical and Geoelectrical Methods
- Seismic Waves and Analysis
- Geological and Geophysical Studies
- Earthquake Detection and Analysis
- earthquake and tectonic studies
- Geophysical Methods and Applications
- Seismology and Earthquake Studies
- Geophysics and Sensor Technology
- Hydrocarbon exploration and reservoir analysis
- Geological and Geochemical Analysis
- Geophysics and Gravity Measurements
- High-pressure geophysics and materials
- Methane Hydrates and Related Phenomena
- NMR spectroscopy and applications
- Mathematical Dynamics and Fractals
- Seismic Imaging and Inversion Techniques
- Algebraic and Geometric Analysis
- Geological Modeling and Analysis
- Scientific Research and Discoveries
- Advanced MEMS and NEMS Technologies
- Fluid Dynamics and Vibration Analysis
- Radiative Heat Transfer Studies
- Geochemistry and Geologic Mapping
- Geomagnetism and Paleomagnetism Studies
- Advanced Mathematical Theories and Applications
Association for the Development of Earthquake Prediction
2014-2021
The University of Tokyo
2014-2021
Earthquake Engineering Research Institute
2014-2020
National Institute of Advanced Industrial Science and Technology
2016-2017
Geological Survey of Japan
2017
Kyoto University
1985-2014
Rikkyo University
2009
Abstract At Naka‐dake cone, Aso caldera, Japan, volcanic activity is raised cyclically, an example of which was a phreatomagmatic eruption in September 2015. Using three‐dimensional model electrical resistivity, we identify magma pathway from series northward dipping conductive anomalies the upper crust beneath caldera. Our resistivity created magnetotelluric measurements conducted November–December 2015; thus, it provides latest information about reservoir geometry The center shifts north...
Abstract Phreatic and phreatomagmatic eruptions represent some of the greatest hazards occurring on volcanoes. They result from complex interactions at a depth between rock, water, magmatic fluids. Understanding assessing such processes remain challenging task, notably because large‐scale characterization volcanic edifices is often lacking. Here we focused Miyakejima Island, an inhabited 8‐km‐wide stratovolcano with regular activity. We imaged its plumbing system through combination four...
Abstract A three‐dimensional (3‐D) lithospheric‐scale electrical resistivity model, developed using network‐magnetotelluric (network‐MT) data, contains structures associated with arc magmatism beneath Kyushu Island in the Southwest Japan arc. Island, where Philippine Sea Plate (PSP) subducts Eurasian plate, can be divided into northern and southern volcanic regions separated by a nonvolcanic region. Many active Quaternary volcanoes occur along front (VF) PSP two regions. Our 3‐D model shows...
Abstract We investigated the magmatic–hydrothermal system of Aso Volcano, Japan, using broadband magnetotelluric (MT) data. To establish nature shallow crust, a previous resistivity model based on data from 100 measurement sites in and around volcano was revised 9 additional near Naka-dake crater, which is located central part volcano. The components MT impedance tipper vector were used to obtain structure by three-dimensional inversion. shows subvertical low-resistivity (< 1 Ωm)...
Abstract A magma supply system is identified in the upper crust beneath Aso caldera, Japan, appearing as a conductive anomaly via three‐dimensional electrical resistivity modeling. caldera contains numerous postcaldera volcanoes, with Naka‐dake cone recently experiencing eruptions at first crater, including an explosive eruption that ejected volcanic ash 11,000 m into air October 2016. The imaged by model consists of four key components: reservoir ~17 km depth corresponds to Conrad...
The M JMA 7.3 Kumamoto earthquake that occurred at 1:25 JST on April 16, 2016, not only triggered aftershocks in the vicinity of epicenter, but also earthquakes were 50–100 km away from epicenter main shock. active seismicity can be divided into three regions: (1) faults, (2) northern region Aso volcano (50 northeast mainshock epicenter), and (3) regions around volcanoes, Yufu, Tsurumi, Garan (100 epicenter). Notably, zones between these are distinctively seismically inactive. electric...
Abstract Our 3‐D electrical resistivity model clearly detects particular subsurface features for magmatism associated with subduction of the Philippine Sea Plate (PSP) in three regions: a southern and northern volcanic region, nonvolcanic region on island Kyushu. We apply inversion analyses geomagnetic transfer function data short‐period band, combination results previous that was determined by using Network‐Magnetotelluric response longer‐period band as an initial present to improve...
Abstract The Beppu–Shimabara graben, a tectonically active region comprising N–S extensional stress field, is characterized by volcanically and seismically regions in the Southwest Japan subduction zone. We determine three‐dimensional electrical resistivity structure of graben inverting network‐magnetotelluric data. Our model indicates that crust beneath discontinuous electrically conductive belt contains four significant anomalies. anomalies are located from east to west as following...
At subduction zones, aqueous fluids released from the subducting slab play an important role in island arc volcanism, triggering partial melting and accretion magmatism. We used Network‐magnetotelluric (MT) method to obtain deep (>100 km), large‐scale electrical resistivity structure beneath Kyushu, Japan, with aim of identifying regions magma that feeds zone volcanoes region. Network‐MT observations, which dipoles about 10–30 km length were measure electric potential difference,...
Abstract We propose a new method for estimating the temperatures and melt fractions of upper mantle. Our is based on connecting electrical conductivity structure from geophysical observations with laboratory‐determined relationships between temperature four nominally anhydrous minerals (olivine, orthopyroxene, clinopyroxene, garnet) basaltic melt. The are expressed as limit using Hashin‐Shtrikman lower bound in solid phases solid‐liquid mixed phases. apply to nonvolcanic two volcanic regions...
Abstract To understand the subduction dynamics around Kyushu Island, Southwest Japan Arc, distribution of fluids is imaged by resolving three‐dimensional (3‐D) electrical resistivity structure beneath a subregion island, including volcanic and nonvolcanic areas. The region in central situated between two regions with numerous Quaternary structures along front aligned N30°E related to Philippine Sea Plate. Two source areas slow slip events lie at depths 20–40 km eastern coast Kyushu, whereas...
According to the ADD model [1], deviation from Newton's inverse square law is expected at below sub-millimeter scale. Present study an experimental investigation of gravitational a short range We have developed setup using torsion balance bar, and succeeded confirm centimeter In addition, composition dependence constant G also tested scale, motivated test weak equivalence principle.
A new experimental technique for short range gravity measurements using pico-precision displacement sensor digital image analysis is presented. We have developed a setup torsion balance pendulum, aiming to test the Newton's inverse square law at below millimeter scale. Weak equivalence principle can also be tested same setup. Detector techniques and detail of are described.