A5088554652- Earthquake Detection and Analysis
- Geomagnetism and Paleomagnetism Studies
- Geophysical and Geoelectrical Methods
- earthquake and tectonic studies
- Seismic Waves and Analysis
- Geophysics and Gravity Measurements
- Geophysical Methods and Applications
- Seismology and Earthquake Studies
- Advancements in Battery Materials
- Advanced Battery Materials and Technologies
- Methane Hydrates and Related Phenomena
- Geological and Geophysical Studies
- Semiconductor materials and devices
- Ionosphere and magnetosphere dynamics
- GaN-based semiconductor devices and materials
- Non-Destructive Testing Techniques
- Ionic liquids properties and applications
- High-pressure geophysics and materials
- Chalcogenide Semiconductor Thin Films
- Solar and Space Plasma Dynamics
- Magnetic confinement fusion research
- Inorganic Chemistry and Materials
- Glass properties and applications
- Copper-based nanomaterials and applications
- Thermal Analysis in Power Transmission
The University of Tokyo
2017-2024
Kobe University
2021-2024
Kyoto University
2008-2021
Nagoya University
2020-2021
Centre for Southern Hemisphere Oceans Research
2017-2019
Earthquake Engineering Research Institute
2019
GNS Science
2019
Association for the Development of Earthquake Prediction
2017
Kanazawa Institute of Technology
2016
Graduate School USA
2014-2015
Abstract In December 2019, the International Association of Geomagnetism and Aeronomy (IAGA) Division V Working Group (V-MOD) adopted thirteenth generation Geomagnetic Reference Field (IGRF). This IGRF updates previous with a definitive main field model for epoch 2015.0, 2020.0, predictive linear secular variation 2020.0 to 2025.0. letter provides equations defining IGRF, spherical harmonic coefficients this model, maps magnetic declination, inclination total intensity their predicted rate...
The electrical conductivity of the ocean is a fundamental parameter in electrodynamics Earth System. This involved number applications ranging from calibration situ flow meters, through extensions traditional induction studies, and into quite new opportunities involving remote sensing properties space-borne magnetometers such as carried aboard three satellites Swarm mission launched 2013. Here, first data set calculated directly observed temperature salinity measurements provided. These...
Abstract On 15 January 2022, at around 04:00 UTC, the submarine volcano Hunga Tonga‐Hunga Ha'apai explosively erupted. We examine data from 10 Pacific Ocean geomagnetic observatories and process using both high pass filters cross‐wavelet analyses to enable evaluating time‐frequency characteristics of magnetic signals across region. At Western Samoa observatory (API), 3–8 min period, visible in vertical horizontal fields, arrived ∼04:44 UTC. The Chichijima Island (CBI) Easter (IPM) had local...
Abstract Tsunami flow coupled with the geomagnetic field generates electric currents and associated magnetic fields. Although electromagnetic (EM) tsunami signals can be used for analysis even forecasting propagation, dynamically self‐consistent effect of shoaling water depth on fluid + electrodynamics has not been adequately clarified. In this study, we classify EM phenomena into three cases based ocean find that deeper results in stronger self‐induction due to increase both phase velocity...
Abstract A seafloor geomagnetic observatory in the northwest Pacific has provided very long vector time-series. It was found that time-series include significant magnetic signals generated by a few giant tsunami events including 2011 Tohoku Tsunami. Here we report tsunami-generated fields consist of weak but first arriving field, and strong second field—similar to P- S-waves seismology. The latter field is result coupling between horizontal particle motions conductive seawater vertical...
Abstract We have submitted a secular variation (SV) candidate model for the thirteenth generation of International Geomagnetic Reference Field (IGRF-13) using data assimilation scheme and magnetohydrodynamic (MHD) dynamo simulation code. This is first contribution to IGRF community from research groups in Japan. A geomagnetic field derived magnetic observatory hourly means, CHAMP Swarm-A satellite data, has been used as input scheme. adopt an ensemble-based scheme, called four-dimensional...
Conductive seawater moving in the geomagnetic main field generates electromotive force ocean. This effect is well known as “oceanic dynamo effect.” Recently, it has been reported that tsunamis are also associated with oceanic effect, and tsunami‐induced electromagnetic variations were actually observed on seafloor. For instance, our research group succeeded observing magnetic seafloor northwest Pacific at time of 2011 Tohoku earthquake. In this study, we developed a domain tsunami simulation...
During the last magmatic eruption period of Aso volcano (November 2014 to May 2015), a controlled-source electromagnetic monitoring experiment (ACTIVE) was conducted. Here, we interpret temporal variations in responses. The ACTIVE system installed at first Nakadake crater, only active crater Aso, consisted transmitter located northwest and four (before eruptions) or three (after vertical induction coil receiver stations. succeeded detecting resistivity structure during latest period....
Abstract We present a new finite element simulation approach in time domain for electromagnetic (EM) fields associated with motional induction by tsunamis. Our method allows us to conduct three‐dimensional realistic smooth bathymetry and readily obtain broad structures of tsunami‐generated EM their evolution, benefitting from implementation efficient unstructured mesh. Highly resolved mesh near observation sites enables compare results observed data investigate tsunami properties terms...
Electrically conductive seawater, moving in an ambient magnetic field, generates electromagnetic (EM) variations. Tsunamis are significant contributors to this phenomenon, inducing observable electric and fluctuations at seafloor coastal observatories. While understanding of these occurrences open oceans is robust, knowledge regarding their observation on islands remains limited. This article seeks, through the use numerical experimentation, enhance our tsunami-generated EM (TGEM) variations...
To evaluate the effect of intra-articular injection gelatin hydrogel microspheres containing basic fibroblast growth factor (bFGF) on experimentally induced defects in third metacarpal bones (MC3s) horses, vivo.6 healthy adult Thoroughbreds.Horses were anesthetized, and a hole (diameter, 4.5 mm) was drilled into medial condyle both MC3s each horse. One milliliter (100 microg) solution (2 mg) bFGF injected joint capsule right metacarpophalangeal horse (bFGF joint). saline (0.9% NaCl) left...
Abstract The motion of conductive seawater by tsunamis can generate magnetic fields in the presence background geomagnetic main field. Previous studies found that, using tsunami‐generated seafloor field, it is possible to predict propagation direction and wave height prior actual arrivals tsunamis. This study correlates tsunami field sea level change observed data three‐dimensional simulations 2009 Samoa 2010 Chile Our direct comparison illustrate that vertical component, , arrived earlier...
Abstract This study presents tsunami inversion analyses that simultaneously use ocean‐bottom pressure and electromagnetic data along with an accurate propagation model to estimate the earthquake source for 2009 Samoa earthquake. was a doublet event occurred pair of normal thrust faults. To best our knowledge, this joint is unprecedented. The incorporation in analysis relatively simple, inclusion frequency dispersion, self‐attraction, loading effects calculations allowed waveforms recorded at...
The Al film prepared by the electroplating method was applied to negative electrode for lithium secondary batteries. electroplated obtained from a 66.7 mol% AlCl3-33.3 EMIC ambient-temperature molten salt melt used. discharge potential of showed flat profile at 0.4 V vs. Li+/Li. capacity 2nd 5th cycle 224-400 mAh g-1 and charge-discharge efficiency maintained ca. 90%. It found that as batteries operates quite effectively.
Recently, electromagnetic observations have become common not only on land but also the seafloor. In particular, thanks to development of instruments for use in shallow seas, one can conduct along land-sea arrays. However, since there is a large contrast conductivity between sea water and rocks crust mantle, we pay more attention accuracy forward solvers used induction problems, including bathymetry. this paper, develop two-dimensional code using triangular finite elements, confirm new by TM...
SUMMARY Although controlled-source electromagnetic (CSEM) methods have higher sensitivity to thin resistive bodies than the magnetotelluric (MT) method, their delineation by inversion requires CSEM data with high signal-to-noise ratio (SNR). This study aims enhance SNR of increasing number stacks. To efficiently stack long-term data, we use an EM-accurately controlled, routinely operated signal system (ACROSS), which can transmit accurately controlled waveforms synchronizing transmitting a...
Earth and Space Science Open Archive This preprint has been submitted to is under consideration at Geophysical Research Letters. ESSOAr a venue for early communication or feedback before peer review. Data may be preliminary.Learn more about preprints preprintOpen AccessYou are viewing the latest version by default [v1]Magnetic Signatures of January 15 2022 Hunga Tonga–Hunga Ha`apai Volcanic EruptionAuthorsNeeshaSchnepfiDTakutoMinamiiDHiroakiTohiDManojNairSee all authors Neesha...