Details of the Researcher

PHOTO

Motoyuki Kido
Section
International Research Institute of Disaster Science
Job title
Professor
Degree

  • 博士（理学）（東京大学）

  • 修士（理学）（東京大学）

Education 1

  • The University of Tokyo　Graduate School of Science

    - 1996/03

Committee Memberships 2

  • 日本測地学会　評議員

    2013/05 - Present

  • 日本測地学会　評議員

    2013/05 - Present

Professional Memberships 3

  • 米国地球物理連合

  • 日本測地学会

  • 日本地震学会

Research Interests 1

  • Seafloor Geodesy

Research Areas 1

  • Natural sciences / Solid earth science /

Papers 84

  1. A Thin and Weak Lithosphere-Asthenosphere Boundary (LAB) Beneath the Oceanic Lithosphere and its Effects on Subduction Earthquake Cycle Deformation 

    Tianhaozhe Sun, Kelin Wang, Jiangheng He, Fumiaki Tomita, Takeshi Iinuma, Ryota Hino, Motoyuki Kido, Yusaku Ohta

    2025/03/18

    DOI： 10.5194/egusphere-egu25-13084 　

  2. Seafloor Crustal Deformation Observations Utilizing Unmanned Surface Vehicles for Monitoring Fault Locking and Sliding Processes at Subduction Zone Plate Boundaries

    Takeshi Iinuma, Motoyuki Kido, Tatsuya Fukuda, Yusaku Ohta, Fumiaki Tomita, Ryota Hino, Hiroaki Takahashi, Takane Hori, Yusuke Yokota

    2025 IEEE Underwater Technology (UT)　1-5　2025/03/02

    Publisher: IEEE

    DOI： 10.1109/ut61067.2025.10947368 　

  3. GNSS-Acoustic positioning error in the vertical component considering the uncertainty of a reference sound speed profile

    Fumiaki Tomita, Motoyuki Kido, Takeshi Iinuma, Yusaku Ohta

    Marine Geophysical Research　46　(1)　2025/02/18

    Publisher: Springer Science and Business Media LLC

    DOI： 10.1007/s11001-025-09563-w 　

    ISSN： 0025-3235

    eISSN： 1573-0581

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    Abstract The precise detection of seafloor crustal deformation is important for understanding various tectonic phenomena, especially the deformation process associated with a seismic cycle. Global Navigation Satellite System–Acoustic (GNSS-A) positioning enables the measurement of horizontal and vertical seafloor deformations. However, vertical motion detected by GNSS-A positioning often has various systematic biases; therefore, the positioning error of vertical motion is typically worse than that of horizontal motion. In this study, we examined one of the systematic bias sources originating from the uncertainty of the reference sound speed profile (SSP) employed in GNSS-A positioning. Using direct oceanographic measurement data, we addressed the uncertainties of using a reference SSP in both cases, where the reference SSP was obtained from direct measurement and the oceanographic data assimilation model (JCOPE2M). We then examined the vertical GNSS-A positioning errors in both cases using the Monte Carlo method: ~2 and ~6 cm in the former and latter cases, respectively. Moreover, we optimized the vertical GNSS-A positioning errors by considering the uncertainty of a reference SSP and other error sources. The optimized vertical GNSS-A positioning errors successfully explain offsets of the campaign solutions deviated from a long-term displacement trend compared with the conventional error evaluations. Although this study focused on the uncertainty of a reference SSP, it is important to carefully evaluate various other systematic error sources to precisely detect vertical seafloor motion.

  4. Development of three-dimensional forward modeling method for the magnetometric resistivity (MMR) method Peer-reviewed

    Noriko Tada, Motoyuki Kido, Nobukazu Seama

    Earth, Planets and Space　76　(1)　2024/10/15

    Publisher: Springer Science and Business Media LLC

    DOI： 10.1186/s40623-024-02063-y 　

    eISSN： 1880-5981

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    Abstract We have developed a 3-D forward modeling method for the magnetometric resistivity (MMR) technique, specially focusing on the marine MMR method, which utilizes a vertical bipole source and seafloor receivers to measure magnetic field variations. The bipole source generates an artificial electric current between two electrodes: one on the sea surface and another on the seafloor. When computing the electric potential using the relaxation method, while conserving electric current, singularities arise at the electrode locations. To address this issue, we introduce two electrical resistivity structures to mitigate the effects of these singularities and to obtain magnetic field anomalies caused by arbitrary 3-D electrical resistivity anomalies beneath the seafloor. By determining the sign of the magnetic field anomaly, we can infer whether the electrical resistivity of the anomalous body is more conductive or more resistive compared to the surrounding oceanic crust. Furthermore, we demonstrate that increasing the number of bipole sources is more effective in exploring anomalous bodies than increasing the number of receivers. Graphical abstract

  5. A new GNSS-acoustic positioning software implementing multiple positioning functions considering nadir total delays Peer-reviewed

    Fumiaki Tomita, Motoyuki Kido

    Earth, Planets and Space　76　(1)　2024/03/26

    Publisher: Springer Science and Business Media LLC

    DOI： 10.1186/s40623-024-01987-9 　

    eISSN： 1880-5981

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    Abstract Global navigation satellite system-acoustic (GNSS-A) positioning is an important geodetic observation technique for detecting seafloor crustal deformation. After the 2011 Tohoku–Oki earthquake, GNSS-A observational networks were extended along various subduction zones, and observational systems have been improved, especially for sea surface platforms, such as the introduction of an unmanned vehicle, the Wave Glider. The aforementioned development of GNSS-A observations has provided a large amount of observational data. Furthermore, GNSS-A positioning methods were recently developed considering the lateral heterogeneity of the sound speed structure. Thus, it is important to develop a software that makes it easy for widespread use of the latest GNSS-A positioning methods. However, there is currently only one open-source GNSS-A positioning software, which may hinder the entry of various researchers into GNSS-A positioning analyses. Here, we developed a new GNSS-A positioning software, henceforth called “SeaGap” (Software of enhanced analyses for GNSS-acoustic positioning), that executes various positioning methods from the conventional kinematic positioning technique to the latest Markov Chain Monte Carlo (MCMC)-based static positioning technique. We introduce their methodology and demonstrate its application to actual observational data. The software newly added optional prior distributions to the unknown parameters expressing the heterogeneity of a sound speed structure into the MCMC-based static positioning method, and we also applied the new method to actual observational data. In addition to the positioning functions, the software contains various auxiliary functions, including drawing. The developed software is written using the “Julia” language and is distributed as an open-source software. Graphical Abstract

  6. The Anticipated Nankai Trough Earthquake and Tsunami in Japan: Determinant Factors of Residents’ Pre-Event Evacuation Intentions Peer-reviewed

    Kanan Hirano, Yo Fukushima, Hiroaki Maruya, Motoyuki Kido, Motoaki Sugiura

    Journal of Disaster Research　18　(3)　233-245　2023/04/01

    Publisher: Fuji Technology Press Ltd.

    DOI： 10.20965/jdr.2023.p0233 　

    ISSN： 1881-2473

    eISSN： 1883-8030

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    As a countermeasure against M8–9 class Nankai Trough earthquakes, the Japan Meteorological Agency started a service to release “Nankai Trough Earthquake Extra Information (Megathrust Earthquake Alert).” This alert is released after an M8.0 or higher earthquake occurs and the possibility of a subsequent earthquake is evaluated to be higher than usual. This is an innovative attempt at disaster mitigation in Japan as it encourages residents in the predefined area to pre-evacuate for one week when tsunami risk is higher. However, the factors influencing the evacuation behavior of residents are unknown. In this study, we investigated factors contributing to residents’ pre-event evacuation intentions using the hierarchical multiple regression analysis. We focused on the extent to which the recognition of the hazards and risks of the Nankai Trough earthquake and the response to the Extra Information, which are changeable by the local governments’ public relations activities, contributed to pre-event evacuation intentions after controlling for disaster-related general attitude and sociodemographic factors. Further, we paid special attention to residents’ degree of recognition of this information by checking the accuracy of their understanding of whether they lived within the pre-event evacuation area. The results showed that the recognition factors were relevant but less so than the general attitude toward disaster and more so than the sociodemographic factors. In addition, residents’ recognition accuracy was low. Our results suggest that it is important for local governments to make adequate efforts to encourage residents to evacuate.

  7. An approximate travel time calculation and a robust GNSS-acoustic positioning method using an MCMC technique Peer-reviewed

    Fumiaki Tomita, Motoyuki Kido

    Earth, Planets and Space　74　(1)　2022/12/02

    Publisher: Springer Science and Business Media LLC

    DOI： 10.1186/s40623-022-01740-0 　

    eISSN： 1880-5981

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    Abstract It is important to consider horizontal heterogeneity in an underwater sound speed structure to accurately estimate positions of GNSS-acoustic sites. Although large amounts of moving survey data (a sea-surface platform moves around when acoustic signals are transmitted) are required to accurately detect a sloping sound speed structure, the actual observational data do not necessarily include sufficient moving survey data due to sea conditions or observational time. To treat these insufficient data, it was assumed that a shallow sound speed gradient was continuously present up to a fixed water depth (gradient depth). However, the validity of this assumption has not been investigated, and the gradient depth has not been optimized. In this study, we developed a new GNSS-acoustic array positioning method that optimizes the gradient depth using an MCMC technique. To employ this technique, we also developed an approximate technique for rapidly calculating travel time, because the conventional travel time calculation requires high computational cost for integration into the MCMC technique. We assessed the performance of the approximate travel time calculation technique and demonstrated its sufficient accuracy and precision for estimating array positions. Then, we applied the new GNSS-acoustic array positioning method to the actual observational data collected by the Japan Coast Guard and Tohoku University. Using enough amounts of the moving survey data, our method demonstrated the results comparable with the conventional GNSS-acoustic positioning method estimating a sloping sound speed structure; thus, the assumption of the sound speed gradient with the fixed water depth was valid. Moreover, due to the physical restriction of this assumption, our method provided robust solutions even when the observational data contained small quantities of moving survey data with a simple sea-surface track. Although our method still cannot be used in the scenario, where no moving survey data are available, it can work robustly compared with the conventional methods. Graphical Abstract

  8. Impact of employing a waveglider on GNSS-Acoustic survey along the Japan trench

    Motoyuki Kido, Chie Honsho, Fumiaki Tomita, Yusaku Ohta, Ryota Hino, Takeshi Iinuma

    2022/03/27

    Publisher: Copernicus {GmbH}

    DOI： 10.5194/egusphere-egu22-2138 　

  9. GNSS-Acoustic Observations of Seafloor Crustal Deformation Using a Wave Glider Peer-reviewed

    Takeshi Iinuma, Motoyuki Kido, Yusaku Ohta, Tatsuya Fukuda, Fumiaki Tomita, Iwao Ueki

    Frontiers in Earth Science　9　2021/03/11

    Publisher: Frontiers Media SA

    DOI： 10.3389/feart.2021.600946 　

    eISSN： 2296-6463

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    Crustal deformation of the seafloor is difficult to observe solely using global navigation satellite system (GNSS). The GNSS-acoustic (GNSS-A) technique was developed to observe seafloor crustal deformation, and it has produced a steady series of successful observations with remarkable results related to crustal deformation associated with huge earthquakes around the Japanese Islands. However, utilizing GNSS-A incurs very large financial and human costs as it requires the use of a research vessel as a surface platform and has a limited observation frequency, which is less than once a year at seafloor stations along the Japan Trench. To conduct frequent observations, an automatic GNSS-A data acquisition system was developed that operates via an unmanned surface vehicle (wave glider). The first observations using this system were performed at a seafloor station off Aomori Prefecture in July 2019. The wave glider was equipped with two GNSS antennas, an acoustic transducer, a microelectromechanical system gyroscope, and associated control and logging units. Data acquisition and autonomous activation of the seafloor stations were successfully executed by controlling the power supply to the payload via satellite communication with the wave glider. The glider rarely strayed off the configured course and the solar panels generated sufficient power to perform the observations although the weather was mostly cloudy. The GNSS-A data processing results show that the position of the station was determined with the same accuracy and precision as in previous observations performed using a research vessel.

  10. Improvement on spatial resolution of a coseismic slip distribution using postseismic geodetic data through a viscoelastic inversion Peer-reviewed

    Fumiaki Tomita, Takeshi Iinuma, Yusaku Ohta, Ryota Hino, Motoyuki Kido, Naoki Uchida

    Earth, Planets and Space　72　(1)　2020/06

    Publisher: Springer Science and Business Media LLC

    DOI： 10.1186/s40623-020-01207-0 　

    ISSN： 1343-8832

    eISSN： 1880-5981

  11. Effects of disturbance of seawater excited by internal wave on GNSS-acoustic positioning Peer-reviewed

    R. Matsui, M. Kido, Y. Niwa, C. Honsho

    Marine Geophysical Research　40　(4)　541-555　2019/12

    Publisher: Springer Science and Business Media {LLC}

    DOI： 10.1007/s11001-019-09394-6 　

  12. Development of a kinematic GNSS-Acoustic positioning method based on a state-space model Peer-reviewed

    Tomita, F, M. Kido, C. Honsho, R. Matsui

    Earth, Planets and Space　71　(102)　2019/09

    DOI： 10.1186/s40623-019-1082-y 　

  13. Assessment of directional accuracy of GNSS-Acoustic measurement using a slackly moored buoy Peer-reviewed

    Imano, M, M. Kido, C. Honsho, Y. Ohta, N. Takahashi, T. Fukuda

    Prog. Earth Planet. Sci.　6　(56)　1-14　2019/08

    Publisher: Springer Science and Business Media LLC

    DOI： 10.1186/s40645-019-0302-1 　

    eISSN： 2197-4284

  14. Offshore Postseismic Deformation of the 2011 Tohoku Earthquake Revisited: Application of an Improved GPS-Acoustic Positioning Method Considering Horizontal Gradient of Sound Speed Structure Peer-reviewed

    C. Honsho, M. Kido, F. Tomita, N. Uchida

    Journal of Geophysical Research: Solid Earth　124　(6)　5990-6009　2019/06

    DOI： 10.1029/2018JB017135 　

    ISSN： 2169-9313

    eISSN： 2169-9356

  15. Seafloor geodesy revealed partial creep of the North Anatolian Fault submerged in the Sea of Marmara Peer-reviewed

    Yamamoto R, M. Kido, Y. Ohta, N. Takahashi, Y. Yamamoto, A. Pinar, D. Kalafat, H. Özener, Y. Kaneda

    Geophys. Res. Lett.　46　(3)　1268-1275　2019/02

    Publisher: American Geophysical Union (AGU)

    DOI： 10.1029/2018GL080984 　

    ISSN： 0094-8276

    eISSN： 1944-8007

  16. A seismogeodetic amphibious network in the Guerrero Seismic Gap, Mexico Peer-reviewed

    Víctor M. Cruz-Atienza, Yoshihiro Ito, Vladimir Kostoglodov, Vala Hjörleifsdóttir, Arturo Iglesias, Josué Tago, Marco Calò, Jorge Real, Allen Husker, Satoshi Ide, Takuya Nishimura, Masanao Shinohara, Carlos Mortera-Gutierrez, Soliman García, Motoyuki Kido

    Seismological Research Letters　89　(4)　1435-1449　2018/07

    DOI： 10.1785/0220170173 　

    ISSN： 0895-0695

    eISSN： 1938-2057

  17. Onboard realtime processing of GPS-acoustic data for moored buoy-based observation Peer-reviewed

    Kido, M, M. Imano, Y. Ohta, T. Fukuda, N. Takahashi, S. Tsubone, Y. Ishihara, H. Ochi, K. Imai, C. Honsho, R. Hino

    J. Disaster Res.　13　(3)　472-488　2018/06

    Publisher: Fuji Technology Press Ltd.

    DOI： 10.20965/jdr.2018.p0472 　

    ISSN： 1881-2473

    eISSN： 1883-8030

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    Realtime observations of vertical/horizontal seafloor movements and sea surface height associated with a huge earthquake are crucial for immediate recognition of its causal fault rupture, so that tsunami early warning can be issued and also the risk of subsequent ruptures can be evaluated. For this purpose, we developed an offshore monitoring system using a moored buoy platform to measure, in realtime, the three observables mentioned above and operated it on a trial basis for a year. While operating the system, GPS-acoustic observation of horizontal movement on the buoy was especially a new challenge. To achieve realtime GPS-acoustic observation under conditions of the limited power supply and narrow bandwidth in satellite communication, we developed special hardware suitable for use on a buoy and software to minimize onboard computational procedures and data transmission. The system functioned properly through the year; 53 regular weekly measurements and 55 on-demand measurements at arbitrary timings. Each measurement consisted of 11 successive acoustic rangings. The buoy tended to drift far from the preferred position for GPS-acoustic measurement, i.e., the center of the seafloor transponder array, due to strong current. The accuracy of the GPS-acoustic positioning achieved ∼46 cm (2σ) even only with “a single ranging” when the buoy was inside the array, while it degraded to ∼1.0 m when the buoy was outside the array. Although the 1.0 m accuracy is a detectable level of possible displacement due to a M8-class earthquake in the source region, further improvement to keep the drifting range smaller despite the current will enhance the utilization of the system.

  18. Learning from crustal deformation associated with the M9 2011 Tohoku-oki earthquake Peer-reviewed

    Wang Kelin, Sun Tianhaozhe, Brown Lonn, Hino Ryota, Tomita Fumiaki, Kido Motoyuki, Iinuma Takeshi, Kodaira Shuichi, Fujiwara Toshiya

    GEOSPHERE　14　(2)　552-571　2018/04

    DOI： 10.1130/GES01531.1 　

    ISSN： 1553-040X

  19. A possible anorthositic continent of early Mars and the role of planetary size for the inception of Earth-like life Peer-reviewed

    Dohm, J.M., Maruyama, S., Kido, M., Baker, V.R.

    Geoscience Frontiers　9　(4)　2018

    DOI： 10.1016/j.gsf.2016.12.003 　

  20. Seafloor geodetic observations to reveal co- and postseismic slip distributions of the 2011 Tohoku-Oki earthquake Peer-reviewed

    Tomita, F, Y. Ohta, T. Iinuma, R. Hino, M. Kido, N. Uchida

    2018 OCEANS - MTS/IEEE Kobe Techno-Oceans (OTO)　1-4　2018

    DOI： 10.1109/OCEANSKOBE.2018.8559370 　

  21. Along-trench variation in seafloor displacements after the 2011 Tohoku earthquake Peer-reviewed

    Fumiaki Tomita, Motoyuki Kido, Yusaku Ohta, Takeshi Iinuma, Ryota Hino

    SCIENCE ADVANCES　3　(7)　e1700113　2017/07

    DOI： 10.1126/sciadv.1700113 　

    ISSN： 2375-2548

  22. Comprehensive Analysis of Traveltime Data Collected Through GPS-Acoustic Observation of Seafloor Crustal Movements Peer-reviewed

    Honsho, C., Kido, M.

    Journal of Geophysical Research: Solid Earth　122　(10)　2017

    DOI： 10.1002/2017JB014733 　

  23. Development and examination of new algorithms of traveltime detection in GPS/acoustic geodetic data for precise and automated analysis Peer-reviewed

    Azuma, R., Tomita, F., Iinuma, T., Kido, M., Hino, R.

    Earth, Planets and Space　68　(1)　1-13　2016/08/11

    DOI： 10.1186/s40623-016-0521-2 　

  24. Extraction of crustal deformations and oceanic fluctuations from ocean bottom pressures Importance of integral studies combining seismology, ocean physics and tsunami engineering technology Peer-reviewed

    Keisuke Ariyoshi, Hiroyuki Matsumoto, Takeshi Iinuma, Naoki Uchida, Akira Nagano, Takuya Hasegawa, Toshihiro Igarashi, Motoyuki Kido, Yusuke Yamashita

    OCEANS 2016 MTS/IEEE MONTEREY　2016

    DOI： 10.1109/OCEANS.2016.7761035 　

  25. Seafloor observations indicate spatial separation of coseismic and postseismic slips in the 2011 Tohoku earthquake Peer-reviewed

    Iinuma, T, R. Hino, N. Uchida, W. Nakamura, M. Kido, Y. Osada, S. Miura

    Nature Communications　7　2016

    DOI： 10.1038/ncomms13506 　

    ISSN： 2041-1723

  26. A trial extraction of crustal deformation from seafloor hydraulic pressure gauges to estimate interplate coupling for subduction plate boundaries Peer-reviewed

    Keisuke Ariyoshi, Akira Nagano, Takuya Hasegawa, Motoyuki Kido, Ryoko Nakata, Hiroyuki Matsumoto, Naoki Uchida, Toshihiro Igarashi

    Proceedings of the 12th SEGJ International Symposium, Tokyo, Japan, 18-20 November 2015　245-247　2015/11/20

    Publisher: Society of Exploration Geophysicists and Society of Exploration Geophysicists of Japan

    DOI： 10.1190/segj122015-079 　

  27. First measurement of the displacement rate of the Pacific Plate near the Japan Trench after the 2011 Tohoku-Oki earthquake using GPS/acoustic technique Peer-reviewed

    Tomita, F., Kido, M., Osada, Y., Hino, R., Ohta, Y., Iinuma, T.

    Geophysical Research Letters　42　(20)　2015/10/28

    DOI： 10.1002/2015GL065746 　

  28. GPS/Acoustic Measurement Using a Multi-purpose Moored Buoy System Peer-reviewed

    Imano M, M. Kido, Y. Ohta, T. Fukuda, H. Ochi, N. Takahashi, R. Hino

    International Association of Geodesy Symposia　2015/08

    DOI： 10.1007/1345_2015_192, 　

  29. Buoy Platform Development for Observation of Tsunami and Crustal deformation Peer-reviewed

    Takahashi N, Y. Ishihara, T. Fukuda, H. Ochi, J. Tahara, T. Mori, M. Deguchi, M. Kido, Y. Ohta, R. Hino, K. Mutoh, G. Hashimoto, O. Motohashi, Y. Kaneda

    International Association of Geodesy Symposia　145　97-103　2015/03

    DOI： 10.1007/1345_2015_114 　

    ISSN： 0939-9585

  30. Investigation on the postseismic deformation associated with the 2011 Tohoku earthquake based on terrestrial and seafloor geodetic observations - to evaluate the further seismic hazard potential on the plate interface beneath the northeastern Japanese Isl Peer-reviewed

    Iinuma T, R. Hino, M. Kido, Y. Osada, D. Inazu, Y. Ito, S. Suzuki, Y. Ohta, H Fujimoto

    International Association of Geodesy Symposia　2015/03

    DOI： 10.1007/1345_2015_162 　

  31. Interplate Coupling in and Around the Rupture Area of the 2011 Tohoku Earthquake (M9.0) Before its Occurrence Based on Terrestrial and Seafloor Geodetic Observations Peer-reviewed

    Iinuma T, R. Hino, M. Kido, Y. Ohta, S. Miura

    International Association of Geodesy Symposia　2015/03

    DOI： 10.1007/1345_2015_48 　

  32. Achievement of the Project for Advanced GPS/Acoustic Survey in the Last Four Years Peer-reviewed

    Kido M, H. Fujimoto, R. Hino, Y. Ohta, Y. Osada, T. Iinuma, R. Azuma, I. Wada, S. Miura, S. Suzuki, F. Tomita, M. Imano

    International Association of Geodesy Symposia　2015/03

    DOI： 10.1007/1345_2015_127 　

  33. Improvement in the Accuracy of Real-Time GPS/Acoustic Measurements Using a Multi-Purpose Moored Buoy System by Removal of Acoustic Multipath Peer-reviewed

    Misae Imano, Motoyuki Kido, Yusaku Ohta, Tatsuya Fukuda, Hiroshi Ochi, Narumi Takahashi, Ryota Hino

    International Association of Geodesy Symposia　105-114　2015

    Publisher: Springer International Publishing

    DOI： 10.1007/1345_2015_192 　

    ISSN： 0939-9585

    eISSN： 2197-9359

  34. Progress in the Project for Development of GPS/Acoustic Technique Over the Last 4 Years Peer-reviewed

    Kido, M, H. Fujimoto, R. Hino, Y. Ohta, Y. Osada, T. Iinuma, R. Azuma, I. Wada, S. Miura, S. Suzuki, F. Tomita, M, Imano

    International Association of Geodesy Symposia　2015

  35. New buoy observation system for tsunami and crustal deformation Peer-reviewed

    Narumi Takahashi, Yasuhisa Ishihara, Hiroshi Ochi, Tatsuya Fukuda, Jun'ichiro Tahara, Yosaku Maeda, Motoyuki Kido, Yusaku Ohta, Katsuhiko Mutoh, Gosei Hashimoto, Satoshi Kogure, Yoshiyuki Kaneda

    MARINE GEOPHYSICAL RESEARCH　35　(3)　243-253　2014/09

    DOI： 10.1007/s11001-014-9235-7 　

    ISSN： 0025-3235

    eISSN： 1573-0581

  36. Prevalence of viscoelastic relaxation after the 2011 Tohoku-oki earthquake Peer-reviewed

    Sun T, K.Wang, T.Iinuma, R.Hino, J.He, H.Fujimoto, M.Kido, Y.Osada, S.Miura, Y.Ohta, Y.Hu

    Nature　514　(7520)　84-87　2014/09

    DOI： 10.1038/nature13778 　

    ISSN： 0028-0836

    eISSN： 1476-4687

  37. 海陸統合測地観測に基づく2011年東北地方太平洋沖地震に関する研究 Peer-reviewed

    藤本博己, 日野亮太, 木戸元之, 伊藤喜宏, 太田雄策, 飯沼卓史, 長田幸仁, 稲津大祐, 鈴木秀市, 佐藤俊也, 立花憲司, 出町知嗣, 三浦哲

    測地学会誌　60　(1)　1-22　2014/05

    Publisher: The Geodetic Society of Japan

    DOI： 10.11366/sokuchi.60.1 　

    ISSN： 0038-0830

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    The geodetic research group of Tohoku University has been carrying out geodetic observations on shore and off shore of Miyagi Prefecture where earthquakes around M7.5 repeatedly occurred at intervals of about 40 years. We have been measuring horizontal movements of seafloor geodetic stations since 2003, using GPS-Acoustic （GPSA） seafloor positioning systems. We have also been continuously observing vertical crustal movements since 2008 using free-fall/pop-up ocean bottom pressure recorders （OBPRs）. Owing to these geodetic observations that were made in the region above the rupture area of the 2011 M9.0 Tohoku-oki earthquake, we succeeded in detecting unexpectedly large coseismic crustal displacements that had never been measured with geodetic systems on the seafloor. We retrieved data from the OBPRs that had been deployed above the rupture area, and to continue monitoring gradual postseismic slips, we installed replacements for these OBPRs at the same observation sites. We presented a model for the coseismic slip distribution on the plate boundary, and it is widely referenced because it is a model that is constrained by the OBPR data as well as the GPSA and the terrestrial geodetic data. We have also developed a method of real-time kinematic analyses of the data from a GNSS array to estimate the approximate magnitude of large earthquakes within several minutes. We developed a procedure to reduce tidal and non-tidal oceanic components in OBPR data. The pressure data analyzed jointly with onshore strain data revealed that there was a slow slip event near the focal zone about one month before the main event. The observed pressure variations also contain information about the coseismic and postseismic crustal movements associated with the M7.3 earthquake that occurred on March 9 and was estimated to be the largest foreshock. These results are important for clarifying geophysical processes that preceded the giant earthquake.

  38. Study of the 2011 off the pacific coast of Tohoku earthquake based on seafloor and terrestrial geodetic observation Peer-reviewed

    Fujimoto, H., Hino, R., Kido, M., Ito, Y., Ohta, Y., Iinuma, T., Osada, Y., Inazu, D., Suzuki, S., Sato, T., Tachibana, K., Demachi, T., Miura, S.

    Journal of the Geodetic Society of Japan　60　(1)　2014

  39. Was the 2011 Tohoku-Oki earthquake preceded by aseismic preslip? Examination of seafloor vertical deformation data near the epicenter Peer-reviewed

    Hino, R, D. Inazu, Y. Ohta, Y. Ito, S. Suzuki, T. Iinuma, Y. Osada, M. Kido, H. Fujimoto, Y. Kaneda

    Mar. Geophys. Res.　35　(3)　181-190　2013/12

    DOI： 10.1007/s11001-013-9208-2 　

    ISSN： 0025-3235

    eISSN： 1573-0581

  40. 衛星通信を活用したリアルタイムGPS解析 −地上通信障害時に地殻変動を実時間で把握するために− Peer-reviewed

    山本淳平, 長田幸仁, 太田雄策, 平原 聡, 出町知嗣, 中山貴史, 立花憲司, 佐藤俊也, 木戸元之, 藤本博己, 日野亮太, 三浦 哲, 内田雅之

    測地学会誌　59　(4)　133-145　2013/10

    Publisher: The Geodetic Society of Japan

    DOI： 10.11366/sokuchi.59.133 　

    ISSN： 0038-0830

    More details Close

    The redundant communication pathway and processing strategy for satellite navigation system such as GPS is extremely important for more reliable quasi real-time crustal deformation monitoring in case of huge interplate earthquake occurrence. We tested real-time kinematic GPS processing (RTK-GPS) via satellite-based mobile phone for redundant communication pathway for address the vulnerabilities of the infrastructure. We succeed to get the stable time series via satellite mobile phone network with almost zero-missing data for short and long baseline RTK-GPS. We also assessed stability, precision and accuracy of StarFireTM global satellites based augmentation system for redundant processing strategy. In order to assess coordinate precision and accuracy, we compared 1Hz StarFire time series and post-processed precise point positioning (PPP) 1Hz time series by GIPSY-OASIS II processing software Ver. 6.1.2 with three different product types (ultrarapid, rapid, and final orbits). We also used different interval clock information (30 and 300 seconds) for the post-processed PPP processing. The standard deviation of real time StarFire time series is less than 30 mm (horizontal components) and 60 mm (vertical component) based on 1 month continuous processing. We also assessed noise spectrum of the estimated time series by StarFire and post-processed GIPSY PPP results. We found that the noise spectrum of StarFire time series is similar pattern with GIPSY-OASIS II processing result based on JPL rapid orbit products with 300 seconds interval clock information. Based on these stability and noise assessment, we suggest that the various communication pathways for RTK-GPS processing and various processing strategy such as global satellites based augmentation system with traditional RTK-GPS processing strategy is important for more reliable quasi real-time crustal deformation monitoring.

  41. Real time GPS processing utilizing satellite communications -Toward more reliable real-time crustal deformation monitoring under a situation of ground communication failure- Peer-reviewed

    Yamamoto, J., Osada, Y., Ohta, Y., Hirahara, S., Demachi, T., Nakayama, T., Tachibana, K., Sato, T., Kido, M., Fujimoto, H., Hino, R., Miura, S., Uchida, M.

    Journal of the Geodetic Society of Japan　59　(4)　2013

  42. Seafloor geodesy: Its present state of affairs and future prospect Peer-reviewed

    Kido, M.

    Journal of the Geodetic Society of Japan　59　(3)　2013

  43. Extended GPS/Acoustic geodetic observation near the Japan Trench axis for the study of the giant 2011 Tohoku-oki earthquake Peer-reviewed

    H. Fujimoto, M. Kido, T. Iinuma, Y. Osada, J. Yamamoto, K. Tadokoro, M. Sato

    2013 IEEE INTERNATIONAL UNDERWATER TECHNOLOGY SYMPOSIUM (UT)　2013

  44. Episodic slow slip events in the Japan subduction zone before the 2011 Tohoku-Oki earthquake Peer-reviewed

    Ito, Y, R. Hino, M. Kido, H. Fujimoto, Y. Osada, D. Inazu, Y. Ohta, T. Iinuma, M. Ohzono, S. Miura, M. Mishina, K. Suzuki, T. Tsuji, J. Ashi

    Tectonophysics　600　14-26　2013

    DOI： 10.1016/j.tecto.2012.08.022 　

    ISSN： 0040-1951

    eISSN： 1879-3266

  45. 海底地殻変動観測の現状と今後の展開 Invited Peer-reviewed

    木戸元之

    測地学会誌　59　(3)　99-109　2013

    Publisher: The Geodetic Society of Japan

    DOI： 10.11366/sokuchi.59.99 　

    ISSN： 0038-0830

    More details Close

    Seafloor geodetic measurements are now recognized as crucial tools to effectively monitor the crustal stress accumulation, especially after the Tohoku Earthquake 2011. The situation promotes the Japanese government to invest in facility of these tools to prepare for devastating disaster. Considering the rapid growth in this field, researchers must manage the tools as sustainable manner both in financial and human costs in order to maximize the efficiency for long-lasting operation. In this paper, current state of the seafloor geodesy and problems arose due to the drastic turn after the earthquake are addressed, then advocate how we should act toward the new era.

  46. Coseismic slip distribution of the 2011 off the Pacific Coast of Tohoku Earthquake (M9.0) refined by means of seafloor geodetic data Peer-reviewed

    T. Iinuma, R. Hino, M. Kido, D. Inazu, Y. Osada, Y. Ito, M. Ohzono, H. Tsushima, S. Suzuki, H. Fujimoto, S. Miura

    JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH　117　2012/07

    DOI： 10.1029/2012JB009186 　

    ISSN： 2169-9313

    eISSN： 2169-9356

  47. Trench-normal variation in observed seafloor displacements associated with the 2011 Tohoku-Oki earthquake Peer-reviewed

    M. Kido, Y. Osada, H. Fujimoto, R. Hino, Y. Ito

    GEOPHYSICAL RESEARCH LETTERS　38　2011/12

    DOI： 10.1029/2011GL050057 　

    ISSN： 0094-8276

  48. Frontal wedge deformation near the source region of the 2011 Tohoku-Oki earthquake Peer-reviewed

    Yoshihiro Ito, Takeshi Tsuji, Yukihito Osada, Motoyuki Kido, Daisuke Inazu, Yutaka Hayashi, Hiroaki Tsushima, Ryota Hino, Hiromi Fujimoto

    GEOPHYSICAL RESEARCH LETTERS　38　2011/08

    DOI： 10.1029/2011GL048355 　

    ISSN： 0094-8276

    eISSN： 1944-8007

  49. Observation of the seafloor acoustic ranging system

    Y. Osada, M. Kido, H. Fujimoto

    2011 IEEE Symposium on Underwater Technology, UT'11 and Workshop on Scientific Use of Submarine Cables and Related Technologies, SSC'11　2011

    DOI： 10.1109/UT.2011.5774110 　

  50. Signal processing of acoustic ranging in GPS/Acoustic seafloor geodesy Peer-reviewed

    M. Kido, H. Fujimoto, Y. Osada

    2011 IEEE Symposium on Underwater Technology, UT'11 and Workshop on Scientific Use of Submarine Cables and Related Technologies, SSC'11　2011

    DOI： 10.1109/UT.2011.5774105 　

  51. Potential tsunamigenic faults of the 2011 off the Pacific coast of Tohoku Earthquake Peer-reviewed

    Takeshi Tsuji, Yoshihiro Ito, Motoyuki Kido, Yukihito Osada, Hiromi Fujimoto, Juichiro Ashi, Masataka Kinoshita, Toshifumi Matsuoka

    EARTH PLANETS AND SPACE　63　(7)　831-834　2011

    DOI： 10.5047/eps.2011.05.028 　

    ISSN： 1343-8832

  52. Long-term stability of acoustic benchmarks deployed on thick sediment for GPS/acoustic seafloor positioning Peer-reviewed

    Hiromi Fujimoto, Motoyuki Kido, Yukihito Osada, Keiichi Tadokoro, Takashi Okuda, Yoshihiro Matsumoto, Kozue Kurihara

    Modern Approaches in Solid Earth Sciences　8　263-272　2011

    Publisher: Springer International Publishing

    DOI： 10.1007/978-90-481-8885-7_13 　

    ISSN： 1876-1682

  53. Utilizing motion sensor data in past seafloor geodetic measurements Peer-reviewed

    Kido, M., Fukimoto, H., Osada, Y.

    Journal of the Geodetic Society of Japan　54　(3)　2008/11

    DOI： 10.11366/sokuchi1954.54.163 　

  54. Development of a seafloor acoustic ranging system toward the seafloor cable network system Peer-reviewed

    Yukihito Osada, Motoyuki Kido, Hiromi Fujimoto, Yoshiyuki Kaneda

    OCEAN ENGINEERING　35　(14-15)　1401-1405　2008/10

    DOI： 10.1016/j.oceaneng.2008.07.007 　

    ISSN： 0029-8018

  55. GPS/acoustic seafloor geodetic observation - Major results and new approaches Peer-reviewed

    Sato, M., Kido, M., Tadokoro, K.

    Journal of the Geodetic Society of Japan　54　(3)　2008

  56. Introduction of 10 Hz GPS receiver for the improved observation of seafloor crustal movement Peer-reviewed

    Osada, Y., Mizukami, T., Kido, M., Ohta, Y., Tsushima, H., Miura, S., Fujimoto, H.

    Journal of the Geodetic Society of Japan　54　(3)　2008

  57. Development of a GPS/A positioning system on a moored buoy for continuous observation of seafloor crustal movements Peer-reviewed

    Fujimoto, H., Kido, M., Osada, Y., Kaneda, Y.

    Journal of the Geodetic Society of Japan　54　(3)　2008

  58. Active faults in the landward slope of the Japan Trench: Insight from seismic data and submersible observation

    Tsuji Takeshi, Ito Yoshihiro, Fujimoto Hiromi, Kido Motoyuki, Ashi Juichiro, YK08-06 Shipboard Scientific Party

    Annual Meeting of the Geological Society of Japan　2008　171-171　2008

    Publisher: The Geological Society of Japan

    DOI： 10.14863/geosocabst.2008.0.171.0 　

    ISSN： 1348-3935

  59. Utilizing motion sensor data in past seafloor geodetic measurements Peer-reviewed

    木戸元之, 藤本博己, 長田幸仁

    J. Geod. Soc. Jap.　54　(3)　163-179　2008

    DOI： 10.11366/sokuchi1954.54.163 　

  60. GPS/音響測距結合方式による海底地殻変動観測 ～観測成果と新たな取り組み～ Peer-reviewed

    佐藤まりこ, 木戸元之, 田所敬一

    測地学会誌　54　(3)　113-125　2008

    Publisher:

    DOI： 10.11366/sokuchi1954.54.113 　

    ISSN： 0038-0830

  61. 10HzGPS受信機導入による海底地殻変動観測高度化の試み Peer-reviewed

    長田幸仁, 水上知子, 木戸元之, 太田雄策, 対馬弘晃, 三浦 哲, 藤本博己

    測地学会誌　54　(3)　141-151　2008

    DOI： 10.11366/sokuchi1954.54.141 　

  62. GPS/A方式海底地殻変動観測に向けた観測システムの開発 Peer-reviewed

    藤本博己, 木戸元之, 長田幸仁, 金田義之

    測地学会誌　54　(3)　181-187　2008

    DOI： 10.11366/sokuchi1954.54.181 　

  63. Temporal variation of sound speed in ocean: a comparison between GPS/acoustic and in situ measurements Peer-reviewed

    Motoyuki Kido, Yukihito Osada, Hiromi Fujimoto

    EARTH PLANETS AND SPACE　60　(3)　229-234　2008

    ISSN： 1343-8832

  64. Detecting horizontal gradient of sound speed in ocean Peer-reviewed

    Motoyuki Kido

    EARTH PLANETS AND SPACE　59　(12)　E33-E36　2007

    ISSN： 1880-5981

  65. Seafloor displacement at Kumano-nada caused by the 2004 off Kii Peninsula earthquakes, detected through repeated GPS/Acoustic surveys Peer-reviewed

    Motoyuki Kido, Hiromi Fujimoto, Satoshi Miura, Yukihito Osada, Kentaro Tsuka, Takao Tabei

    EARTH PLANETS AND SPACE　58　(7)　911-915　2006

    DOI： 10.1186/BF03351996 　

    ISSN： 1343-8832

  66. 海底地殻変動観測による沈み込み運動の現場観測 Invited

    藤本博巳, 三浦哲, 日野亮太, 木戸元之, 長田幸仁

    月刊地球　51　(51)　188-192　2005

    Publisher:

    ISSN： 0916-9733

  67. 1-D resistivity structures of the oceanic crust around the hydrothermal circulation system in the central Mariana Trough using Magnetometric Resistivity method Peer-reviewed

    N Tada, N Seama, TN Goto, M Kido

    EARTH PLANETS AND SPACE　57　(7)　673-677　2005

    DOI： 10.1186/BF03351846 　

    ISSN： 1343-8832

  68. Magnetic dipole anomalies as indicators of mantle wedge serpentinization Peer-reviewed

    Y Kido, M Kido, K Fujioka

    GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS　5　(8)　doi:10.1029/2004GC000697　2004/08

    DOI： 10.1029/2004GC000697 　

    ISSN： 1525-2027

  69. 局在化アドミッタンスで見るリソスフェア Invited

    木戸元之

    月刊地球　25　(7)　530-534　2003

    Publisher:

    ISSN： 0387-3498

  70. Continuous wavelet-like filter for a spherical surface and its application to localized admittance function on Mars Peer-reviewed

    M Kido, DA Yuen, AP Vincent

    PHYSICS OF THE EARTH AND PLANETARY INTERIORS　135　(1)　1-16　2003/01

    DOI： 10.1016/S0031-9201(02)00176-0 　

    ISSN： 0031-9201

  71. Geophysical applications of multidimensional filtering with wavelets Peer-reviewed

    DA Yuen, AP Vincent, M Kido, L Vecsey

    PURE AND APPLIED GEOPHYSICS　159　(10)　2285-2309　2002/09

    DOI： 10.1007/s00024-002-8736-5 　

    ISSN： 0033-4553

  72. Numerical simulation for the prediction of the plate motions: Effects of lateral viscosity variations in the lithosphere Peer-reviewed

    M Yoshida, S Honda, M Kido, Y Iwase

    EARTH PLANETS AND SPACE　53　(7)　709-721　2001

    DOI： 10.1186/BF03352399 　

    ISSN： 1343-8832

  73. The role played by a low viscosity zone under a 660 km discontinuity in regional mantle layering Peer-reviewed

    M Kido, DA Yuen

    EARTH AND PLANETARY SCIENCE LETTERS　181　(4)　573-583　2000/09

    DOI： 10.1016/S0012-821X(00)00217-X 　

    ISSN： 0012-821X

  74. Mantle viscosity derived by genetic algorithm using oceanic geoid and seismic tomography for whole-mantle versus blocked-flow situations Peer-reviewed

    M Kido, DA Yuen, O Cadek, T Nakakuki

    PHYSICS OF THE EARTH AND PLANETARY INTERIORS　107　(4)　307-326　1998/05

    DOI： 10.1016/S0031-9201(98)00077-6 　

    ISSN： 0031-9201

  75. New perspectives on mantle dynamics from high-resolution seismic tomographic model P1200 Peer-reviewed

    O Cadek, DA Yuen, H Cizkova, M Kido, HW Zhou, D Brunet, P Machetel

    PURE AND APPLIED GEOPHYSICS　151　(2-4)　503-525　1998/03

    DOI： 10.1007/s000240050126 　

    ISSN： 0033-4553

  76. ジオイドからわかるマントルレオロジー Invited

    木戸元之

    月刊地球　20　265-270　1998

  77. Synthetic tests of geoid-viscosity inversion: A layered viscosity case Peer-reviewed

    M Kido, S Honda

    EARTH PLANETS AND SPACE　50　(11-12)　1055-1065　1998

    DOI： 10.1186/BF03352200 　

    ISSN： 1343-8832

  78. Inferences of viscosity from the oceanic geoid: Indication of a low viscosity zone below the 660-km discontinuity Peer-reviewed

    M Kido, O Cadek

    EARTH AND PLANETARY SCIENCE LETTERS　151　(3-4)　125-137　1997/10

    DOI： 10.1016/S0012-821X(97)81843-2 　

    ISSN： 0012-821X

  79. MORPHOLOGICAL-STUDIES OF THE AYU TROUGH, PHILIPPINE-SEA CAROLINE PLATE BOUNDARY Peer-reviewed

    T FUJIWARA, K TAMAKI, H FUJIMOTO, T ISHII, N SEAMA, H TOH, K KOIZUMI, C IGARASHI, J SEGAWA, K KOBAYASHI, M KIDO, T SENO, H KINOSHITA

    GEOPHYSICAL RESEARCH LETTERS　22　(2)　109-112　1995/01

    DOI： 10.1029/94GL02719 　

    ISSN： 0094-8276

  80. DYNAMIC TOPOGRAPHY COMPARED WITH RESIDUAL DEPTH ANOMALIES IN OCEANS AND IMPLICATIONS FOR AGE-DEPTH CURVES Peer-reviewed

    M KIDO, T SENO

    GEOPHYSICAL RESEARCH LETTERS　21　(8)　717-720　1994/04

    DOI： 10.1029/94GL00305 　

    ISSN： 0094-8276

  81. アユトラフとはなにか？ —白鳳丸KH92-1 航海地球物理調査の成果—

    富士原敏也, 木戸元之, 玉木賢策, 藤本博巳, 瀬野徹三, 木下肇, 藤浩明, 石井輝秋, 五十嵐千秋, 小林和男, 瀬川爾朗

    月刊海洋　24　(9)　532-538　1994

  82. 海洋プレートの進化に関する研究の動向 Peer-reviewed

    木戸元之, 木下肇

    地震　47　468-488　1994

    DOI： 10.4294/zisin1948.47.4_469 　

  83. 地震波トモグラフィーから予想される現在のマントル対流パターンについて Peer-reviewed

    木戸元之

    地震　47　411-421　1994

    DOI： 10.4294/zisin1948.47.4_411 　

  84. Geophysical and Geological Research of the Ayu Trough of KH92-1 Cruise, R/V Hakuho-maru

    Fujiwara T., Ishii T., Tamaki K., Fujimoto H., Toh H., Koizumi K., Igarashi C., Kobayashi K., Segawa J., Kido M., Seno T., Kinoshita H., Takemura O., Yokose H.

    PROGRAMME AND ABSTRACTS THE VOLCANOLOGICAL SOCIETY OF JAPAN　1992　176-176　1992

    Publisher: The Volcanological Society of Japan

    DOI： 10.18940/vsj.1992.2.0_176 　

Show all ︎Show first 5

Misc. 12

  1. GNSS-Acoustic seafloor geodetic observations and their results along the Japan-Kuril trench

    富田史章, 木戸元之, 飯沼卓史, 太田雄策, 日野亮太, 大園真子, 高橋浩晃, PLATA-MARTINEZ Raymondo, 野徹雄, 中東和夫, 中村恭之

    日本地震学会秋季大会講演予稿集(CD-ROM)　2023　2023

  2. GNSS-Acoustic Observation Using the Wave Glider to Detect the Seafloor Crustal Deformation (3)

    飯沼卓史, 木戸元之, 福田達也, 太田雄策, 富田史章, 有吉慶介, 永野憲, PLATA-MARTINEZ Raymundo, 日野亮太, 高橋浩晃, 堀高峰

    日本測地学会講演会要旨　138th　2022

  3. Recent GNSS-Acoustic seafloor geodetic observations off Tohoku and their results

    富田史章, 木戸元之, 飯沼卓史, 太田雄策, 本荘千枝, 日野亮太, 野徹雄, 中東和夫

    日本地震学会秋季大会講演予稿集(CD-ROM)　2022　2022

  4. 新しいプレート境界モデルに向けた海底地震地殻変動モニタリング観測研究と技術開発

    篠原雅尚, 塩原肇, 望月公廣, 山田知朗, 一瀬建日, 村井芳夫, 日野亮太, 藤本博己, 木戸元之, 伊藤喜宏, 佐藤利典, 清水洋, 八木原寛, 酒井慎一, 小原一成, 平田直

    日本地震学会秋季大会講演予稿集　2012　34　2012/10/01

  5. A long-term seafloor experiment using an acoustic ranging system: Precise horizontal distance measurements for detection of seafloor crustal deformation

    Osada, Y., Kido, M., Fujimoto, H.

    Ocean Engineering　51　2012

    DOI： 10.1016/j.oceaneng.2012.05.006 　

  6. GPS/Acoustic measurement with higher accuracy by means of stationary survey

    Kido, M, H. Fujimoto, Y. Osada

    Proc. 22nd Ocean Engineering Symposium, Tokyo, March 17-18, 2011　OES22　039　2011

  7. P-53 Seismic, geodetic and cold-seepage observations for detection of slow earthquakes on landward slope of Japan Trench

    Ito Y., Fujimoto H., Hino R., Kido M., Osada Y., Suzuki S., Yamamoto Y., Azuma R., Suzuki K., Tsuji T., Nakayama N., Ashi J., Gamo T.

    115　198-198　2008/09/15

    Publisher: The Geological Society of Japan

  8. 2004年紀伊半島南東沖地震震源域周辺の海底観察と地殻変動観測用海底局の姿勢安定性の検証

    藤本博己, 木戸元之, 長田幸仁, 田所敬一, 奥田隆, 松本良浩, 栗原梢

    海洋研究開発機構航海概要報告(CD-ROM)　2006　2008

  9. Detecting horizontal gradient of sound speed in ocean

    KIDO Motoyuki

    EPS　59　(12)　e33-e36　2007/12/01

    Publisher: Terra Scientific Pub. Co.

    ISSN： 1343-8832

  10. 海底地殻変動観測用海底局の安定性:2004年紀伊半島南東沖地震後の潜航調査

    藤本博己, 田所敬一, 奥田隆, 松本良浩, 木戸元之, 長田幸仁, 栗原梢

    しんかいシンポジウム予稿集　23rd　2007

  11. Toward semi-real-time GPS/A seafloor positioning with a moored Buoy

    Fujimoto, H, M. Kido, Y. Osada, Y. Kaneda

    Proc. Symposium on Underwater Technology 2007 and International Workshop on Scientific Use of Submarine Cables and Related Technologies 2007, Tokyo, April 2007　IEEE Catalog Number: 07EX1770C　211-216　2007

    DOI： 10.1109/UT.2007.370787 　

  12. 2004年紀伊半島南東沖地震後における海底地殻変動観測用海底局の安定性に関する潜航調査

    藤本博己, 田所敬一, 奥田隆, 松本良浩, 木戸元之, 長田幸仁, 栗原梢

    日本測地学会講演会要旨　106th　2006

Show all ︎Show first 5

Presentations 16

  1. 海底地殻変動観測手法高度化における問題点とその解決のための提案

    木戸元之, 長田幸仁, 藤本博己

    日本地球惑星科学連合2010年　2011/05/25

  2. Temporal variation of oceanic sound speed structure affecting seafloor geodesy International-presentation

    Kido, M, H. Fujimoto, Y. Osada

    2010 AGU Fall Meeting　2010/12/13

  3. 海底地殻変動観測のこれまでの成果と今後の展望について

    木戸元之, 長田幸仁, 藤本博己

    日本地震学会2010年秋季大会　2010/10/28

  4. 海底地殻変動観測システムの高度化

    木戸元之

    「地震及び火山噴火予知のための観測研究計画」成果報告シンポジウム　2010/03/03

  5. GPS/音響方式による海底地殻変動観測の精度改善への取り組み

    日本地震学会2009年秋季大会　2009/10

  6. Seafloor geodesy using the GPS/acoustic technique: towards next generation approach

    第21回海洋工学シンポジウム　2009/08

  7. Technical development of analysis in seafloor geodetic measurement

    木戸元之, 長田幸仁, 藤本博

    日本地球惑星科学連合大会　2009/05

  8. 分岐断層活動検出へ向けた海底間音響測距装置の安定した潜航設置―NT08-19航海（熊野灘外縁部）の概要―

    木戸元之, 長田幸仁, 岩崎望, 兵藤一星, 荒井崇臣, 山根広, 岩本久則

    Blue Earth Symposium　2009/03

  9. Development of a new tubular buoy for seafloor geodetic observation with cabled system International-presentation

    Kido, M, Y. Osada, H. Fujimoto, Y. Kaneda

    AGU 2008 Fall meeting　2008/12/15

  10. Tracking buoy motion/attitude using incomplete rate-gyro data in the GPS/acoustic measurement International-presentation

    Kido, M, H. Fujimoto, Y. Osada

    ASC-SSJ　2008/11/24

  11. 海中音速傾斜推定における誤差伝播について

    木戸元之, 長田幸仁, 藤本博己

    日本測地学会第110回講演会　2008/10/22

  12. 係留ブイ方式に向けた海底地殻変動観測システムの開発

    木戸元之, 長田幸仁, 藤本博己, 金田義行

    日本地球惑星科学連合2008年大会　2008/05/25

  13. Monitoring the Lateral Gradient of Sound Speed in Ocean Toward Fast GPS/Acoustic Seafloor Positioning for the Cabled System International-presentation

    AGU Fall Meeting　2007/12/10

  14. 海底地殻変動観測における傾斜を含む音速場の推定と観測精度について

    日本測地学会 第108回講演会　2007/11/08

  15. GPS/音響海底測地観測における海中音速の傾きについて

    木戸元之, 長田幸仁, 藤本博己

    日本地震学会秋季大会　2007/10/24

  16. A feasibility study of monitoring of the horizontal gradient of sound speed in ocean International-presentation

    EASTEC symposium 2007　2007/09/19

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Research Projects 9

  1. Waveglider-based GNSS-acoustic survey utilized oceanographic model

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (B)

    Institution: Tohoku University

    2024/04/01 - 2027/03/31

  2. 津波情報の即時伝達のための水中音響伝送手法の開発

    高橋 成実, 木戸 元之, 今井 健太郎, 越智 寛, 石原 靖久, 太田 雄策, 福田 達也, 近貞 直孝

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 基盤研究(B)

    Institution: 国立研究開発法人防災科学技術研究所

    2020/04/01 - 2023/03/31

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    2011年の東日本大震災では、高さ40mを超える津波が襲来し、甚大な被害が発生した。これを受け、日本海溝沿いには日本海溝海底地震津波観測網が敷設され、海底での津波観測と海域での水圧値を用いた津波予測技術が進展し（Tsushima et al., 2012; Takahashi et al., 2018）、いくつかのシステムは気象庁や自治体に実装された。しかし、海底観測網の整備と運用にはコストや人的負担が大きいため、全海域に敷設するのは難しい。遠地地震の監視を目的として、DARTブイシステム（https://nctr.pmel.noaa.gov/Dart/）が太平洋沿岸には設置、運用されているが、これも日本列島南方に流れる黒潮下では、その強潮流により設置することができず、全ての海域に設置できるものではない。これを解決するために、海底で観測した水圧値を音響信号に変換し、複数の中継器を経由して海面に伝送、衛星を通じて陸上にデータを伝送するシステムを検討している。 これを実現するために必要な技術は、海中部のノイズや海面や海底からの反射ノイズに強いこと、消費電力が抑えられて長期的な利用が可能であること、観測データの精度が確保できることである。これを検討するために、一定の数値を音響信号に変換して伝送する音響通信試験を6日間にわたり田沢湖で実施した。通信試験では、湖底に送信機を設置し、２つの一定値を使用して、音響データを直接湖面の受波機に伝送するケースと、中継器でデータを中継してから受波機に伝送するケースの2つの経路で伝送されたデータを比較し、音響伝送の安定性評価を行った。

  3. GPS/D-Acoustic survey using closely installed transponders

    Kido Motoyuki

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Challenging Research (Exploratory)

    Institution: Tohoku University

    2017/06/30 - 2019/03/31

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    A new approach was proposed and verified that uses acoustic ranging from the sea surface at a site of localized strain of seafloor being expected, where traditional seafloor ranging has difficulty in acoustic paths not to be interfered by seafloor topography. During a sea trial at the reverse fault along the Japan trench, we confirmed that measured accuracy of strain is reasonable and the no significant strain was observed for the campaign period. On the contrary, during a sea trial off the Kii-peninsula, extremely complicated temperature perturbation was observed, which cannot adequately be corrected for. This indicated that the proposed approach is not always applicable to all the possible seafloor conditions and should be assessed beforehand.

  4. Integral analysis of ocean bottom pressure change due to crustal deformation and oceanic depth profile change: New application of dense sealfoor networks

    Ariyoshi Keisuke

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (B)

    Institution: Japan Agency for Marine-Earth Science and Technology

    2015/04/01 - 2019/03/31

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    In this study, we observed depth profile of salinity and temperature along Nankai Trough and Japan Trench around Hokkaido, which enables us to evaluate the oceanic fluctuation component for hydraulic pressure on the seafloor. From our analyses, we demonstrated that impact of sea surface height change driven by Kuroshio large meander have time lag about one month to the seafloor, and that unreasonable signal during the postseismic deformation of the 2003 Tokachi earthquake is explained from a meso-scale eddy observed from line observational data.

  5. Slow slip to the trench ?

    Ito Yoshihiro, HINO Ryota, OBARA Kazushige, SHINOHARA Masanao, MOCHIZUKI Kimihiro

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (A)

    Institution: Kyoto University

    2014/04/01 - 2019/03/31

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    We investigated slow slip events in the Hikurangi Margin, New Zealand with ocean bottom pressure observations and numerical modeling based on the observation data. Our results from the pressure data indicated that the slip area of the slow slip event in 2014 reached the trench in the 2014 slow slip event. Our numerical model simulated the dynamic effect on triggering the slow slip event after the 2016 Kaikoura earthquake captured features of the actual slow slip event observed after the mainshock.

  6. Improvement in seafloor geodetic measurements by means of evaluation of sound speed variation in ocean

    Kido Motoyuki

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Challenging Exploratory Research

    Institution: Tohoku University

    2015/04/01 - 2017/03/31

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    It is crucial for improvement in seafloor geodetic measurement to evaluate sound speed variation in ocean. In order to construct a proper ocean model, we conducted intensive continuous measurement of temperature profile in ocean using XBT, which is an expandable thermistor. Based on its obtained data, we proved that short-period variation is mainly caused by internal gravity waves. Using internal wave model, we construct correction method for sound speed, which leads improvement in detecting horizontal movement and even vertical one.

  7. Development of the high accuracy attitude determination system for the GNSS/Acoustic seafloor geodetic observation

    Ohta Yusaku

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Challenging Exploratory Research

    Institution: Tohoku University

    2015/04/01 - 2017/03/31

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    For the accuracy and precision improvement of the geodetic observation in the offshore region, low power consumption system for the position and attitude estimation is extremely important. This research achieved (1) development of the low power consumption GNSS continuous observation system for the moored buoy environment and (2) development of new algorithm for the precise and accurate estimation deduced from the 1 GNSS antenna and MEMS gyro. We succeeded to develop the low power consumption GNSS observation system which contain the real-time PPP processing and the GNSS phase data recording with less than 3 W power consumption. We also developed the new algorithm for the attitude determination based on the 1 GNSS antenna and MEMS gyro. Based on our algorithm, we succeeded to estimate the attitude with the accuracy of 0.5, 0.4, and 0.4 degree for the Yaw, Pitch and Roll angle, respectively.

  8. Multi-scale types of slow earthquakes based on ocean-bottom geodetic and seismological observations

    FUJIMOTO Hiromi, ITO Yoshihiro, ITO Yoshihiro, HINO Ryota

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (A)

    Institution: Tohoku University

    2008 - 2012

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    We have observed two slow slip events in the Japan subduction zone. The slow slip events was observed in 2008 and 2011 by ocean-bottom geodetic network that had been newly established on the present work. Moderate and large Interpate earthquakes in 2008 and 2011 were preceded by the slow slip events respectively. The slow slip event in 2011 preceded the largest foreshock of the 2011 Tohoku-Oki earthquake. These suggest that slow slip plays an leading role in stress buildup to earthquake generation.

  9. 海底地殻変動観測 Competitive

    System: Funded Research

    2003/04 -

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Other 1

  1. 海底地殻変動観測技術の高度化

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    今後予想される海溝型巨大地震の想定震源域は海域にあり、その周辺における地殻変動観測により、プレート境界の固着状態の空間分布を把握し、その時間変動をモニターすることが今後の重要な課題である。そのためには、想定震源域とその周辺において広域かつ高密度で精密な地殻変動連続観測が必要である。しかし現状のGPS音響結合方式の海底地殻変動観測は、条件により測位精度1～5cm程度の孤立した点における観測であり、観測頻度は多くても年に2～3回の繰り返し観測である。しかも観測の結果が得られるのは1か月程度経過したのちである等の問題点が存在する。本研究は、その海底地殻変動の高度化を実現するために必要な観測システム及び解析手法を開発することを目的とするものである。当初平成26年度までの5年計画の予定であったが、平成23年度補正予算による研究の強化により、本研究は、平成25年度までに1回の測位精度を1cm程度まで向上させ、海溝型巨大地震の想定震源域内及びその周辺や東北地方太平洋沖地震の余効変動域における広域・高密度観測を進め、速報値を観測終了後半日程度で求め、セミリアルタイム化を実現することを目標とする。重要な観測点においては係留ブイによる連続観測を実現し、日座標値の時系列データを得られるようにする。今後の観測形態としては、船を用いた移動観測と自航式ブイを用いた同時観測、さらに係留ブイを用いた連続観測が必要となることを踏まえ、①移動観測における高精度かつ高効率な海底地殻変動観測・解析技術の開発、②セミリアルタイム海底地殻変動連続観測に向けたシステム開発、及び集中観測による東北地方太平洋沖地震の余効変動の検出を目標として本業務を実施する。