A5019017004- Geological and Geochemical Analysis
- earthquake and tectonic studies
- High-pressure geophysics and materials
- Hydrocarbon exploration and reservoir analysis
- Geotechnical and Geomechanical Engineering
- Seismology and Earthquake Studies
- Cardiac Imaging and Diagnostics
- Mineralogy and Gemology Studies
- Geological and Geophysical Studies
- Methane Hydrates and Related Phenomena
- Geological Studies and Exploration
- Geochemistry and Geologic Mapping
- Paleontology and Stratigraphy of Fossils
- Drug-Induced Ocular Toxicity
- CO2 Sequestration and Geologic Interactions
- Seismic Imaging and Inversion Techniques
- Geology and Paleoclimatology Research
- Cardiovascular Function and Risk Factors
- Cardiac tumors and thrombi
- Calcium Carbonate Crystallization and Inhibition
- Enhanced Oil Recovery Techniques
- Topic Modeling
- Nicotinic Acetylcholine Receptors Study
- Pericarditis and Cardiac Tamponade
- Sleep and Work-Related Fatigue
Tokyo Gakugei University
2023-2024
The University of Tokyo
2020-2024
University of Southern California
2020
Tohoku University
2016-2020
Nagoya University
2012-2020
Graduate School USA
2017-2020
Planetary Science Institute
2015
Abstract Deep tectonic tremor downdip of the seismogenic zone in warm subduction zones is thought to occur region high fluid pressures. However, deformation and processes responsible for are poorly understood. We examined Tomuru metamorphic rocks on Ishigaki Island, southern Ryukyu Arc, deformed at ∼40 km depth ∼450°C under epidote‐blueschist metamorphism comparable source northern Cascadia zone. Here, quartz vein‐rich metapelite metabasite repeated many times as a result duplex...
Mantle wedge domains beneath the forearc Moho are unique regions of Earth’s interior where mantle encounters subducting oceanic plates. Crystal-plastic deformation and fluid-induced reactions in supra-subduction control global material circulation, arc volcanism, seismicity within subduction zones. The Sanbagawa metamorphic belt contains numerous ultramafic blocks its higher-grade zones, some which likely originated as lower crustal cumulates that were subsequently incorporated into...
Abstract It is widely accepted that water-rich serpentinite domains are commonly present in the mantle above shallow subducting slabs and play key roles controlling geochemical cycling physical properties of subduction zones. Thermal petrological models show dominant serpentine mineral antigorite. However, there no good consensus on amount, distribution alignment this mineral. Seismic velocities used to identify antigorite-rich domains, but antigorite highly-anisotropic depending seismic ray...
The fine structure of goldfish (Carassius auratus) asterisci, which consists vaterite—a metastable polymorph anhydrous calcium carbonate—has been investigated and compared with inorganically synthesized vaterites, using electron microscopy. This is as a first step in elucidating the mechanism selection carbonate biomineralization otoliths. X-ray diffraction analyses suggested that there was no marked difference unit cell parameters, supercell structure, or stacking disorder features between...
Abstract The Sanbagawa metamorphic belt of southwest Japan is one the type localities subduction‐related high‐ P metamorphism. However, variable pressure–temperature ( – T ) paths and metabasic assemblages have been reported for eclogite units in region, leading to uncertainty about subduction zone paleo‐thermal structure associated tectonometamorphic conditions. To analyse this variation, phase equilibria modelling was applied three main rock types documented region glaucophane eclogite,...
Abstract Raman CM geothermometry applied to 126 samples of pelitic schists collected over an area 11 km × 7 reveals the thermal structure Asemigawa region Sanbagawa metamorphic belt, southwest Japan in unprecedented detail. In general, estimated temperatures gradually increase from south north range 288–553°C. However, a temperature gap ~380 ~440°C is identified near boundary between chlorite and garnet zones. This matches depth continental Moho subduction zone. The gradient...
Abstract Shock recovery experiments were performed using a two-stage light gas gun to clarify the progressive deformation microstructures of calcite at submicron scale concerning pressure. Decaying compression pulses produced projectile that was smaller than natural marble target. In two experiments, samples shocked 13 and 18 GPa epicenters targets. Calcite grains in pressure range 1.1–18 examined polarized microscopy (scanning) transmission electron microscopy. The density free dislocations...
Abstract Talc is widely distributed over the Earth's surface and predicted to be formed in various tectonic settings. a very soft anisotropic sheet silicate showing low friction behavior. Therefore, formation of talc expected weaken strength talc-bearing rocks may associated with initiation subduction, decrease coupling coefficient resulting aseismic movements along faults shear zones within subduction zones. For these reasons, understanding crystallographic preferred orientation (CPO)...
Abstract. Maximum shear stress along an active deformation zone marking the subduction plate interface is important for understanding earthquake phenomena and input parameter in thermomechanical modeling. However, such maximum difficult to measure directly at depths more than a few kilometers generally estimated by simulation using range of parameters with large associated uncertainties. In addition, values represent conditions over short observation timescales, which may not be applicable...
Abstract Garnet peridotite xenoliths have been rarely reported from suboceanic mantle. Petrographic and geochemical characteristics of garnet-bearing oceanic provide precious information on dynamics the lithosphere asthenosphere interaction. We examined a lherzolite xenolith included in olivine nephelinite lava Aitutaki Island, member Cook-Austral volcanic chain. The contains reddish fine-grained (< 5 µm size) mineral aggregates (FMAs) with size range 0.5–6 mm, consisting olivine, calcic...
Growth histories recorded in garnet grains metasedimentary rocks from the Sanbagawa belt Japan and Mogok Myanmar were analyzed using an effective combination of electron backscatter diffraction (EBSD) probe microanalysis (EPMA) data. Garnet metapelite has inner outer zones that formed eclogite epidote-amphibolite facies stages, respectively. Based on EPMA element mapping, this appears to have grown as a single crystal with temporal break growth between occurred during exhumation. The EBSD...
Abstract Garnet grains in Sanbagawa quartz eclogites from the Besshi region, central Shikoku commonly show a zoning pattern consisting of core and mantle/rim that formed during two prograde stages eclogite subsequent epidote–amphibolite facies metamorphism, respectively. are grouped into four types (I, II, III, IV) according to compositional trends their cores. Type I garnet is most common sometimes coexists with other thin section. epidote kyanite stage. The inner cores II III crystallized...
Deep slow earthquakes are commonly observed downdip from the seismogenic zone in relatively warm subduction zones. Most of these events occur close to Moho depth overriding plate at depths 30&#8211;40 km. Slow show characteristics that can be related both brittle and ductile behavior their occurrence is thought closely brittle-ductile transition. There also good evidence develop regions high fluid pressure. The temperature zones an important control on location transition release healing...
Abstract Lithologic heterogeneity and the presence of fluids have been linked to seamount subduction collocated with slow earthquakes. However, deformation mechanisms fluid conditions associated remain poorly understood. The exhumed Chichibu accretionary complex on Amami-Oshima Island preserves mélange shear zones composed mudstone-dominated basalt–limestone deformed under sub-greenschist facies metamorphism. contains sandstone, siliceous mudstone, basalt lenses in an illitic matrix....
Abstract Feather features (FFs) in quartz consist of a planar fracture (PF) and associated fine lamellae (FF lamellae; FFL) have been observed various natural impact structures. However, the mechanisms conditions FF formation are poorly understood. We conducted shock recovery experiments on granite using decaying compressive pulses to investigate FFs. characterized recovered samples an optical microscope equipped with universal stage, scanning electron combined back‐scattered diffraction...