Furuya Masato
| Faculty of Science Earth and Planetary Sciences Earth and Planetary Dynamics | Professor |
| Arctic Research Center | Professor |
Last Updated :2025/11/06
■Researcher basic information
Researchmap personal page
Home Page URL
Researcher number
- 60313045
Researcher ID
- E-1296-2011
J-Global ID
Research Keyword
Research Field
- Natural sciences, Space and planetary science
- Environmental science/Agricultural science, Environmental dynamics
- Natural sciences, Atmospheric and hydrospheric science
- Social infrastructure (civil Engineering, architecture, disaster prevention), Disaster prevention engineering
- Natural sciences, Solid earth science
Educational Organization
- Bachelor's degree program, School of Science
- Master's degree program, Graduate School of Science
- Doctoral (PhD) degree program, Graduate School of Science
■Career
Career
- Jan. 2012 - Present
Hokkaido University, Faculty of Science, Department of Earth and Planetary Sciences, Professor, Japan - Oct. 2007 - Dec. 2011
Hokkaido University, Faculty of Science, Department of Earth and Planetary Sciences, Associate Professor, Japan - Apr. 1999 - Sep. 2007
The University of Tokyo, Earthquake Research Institute, Assistant professor, Japan - Aug. 2003 - Jul. 2005
University of Colorado at Boulder, Department of Physics, Visiting assistant professor, 文部科学省在外研究員(+CIRES Visiting Fellow 2004-2005), United States - Apr. 1997 - Mar. 1999
Communications Research Laboratory, MPT, Researcher, Japan
Educational Background
Committee Memberships
- Oct. 2023 - Present
Progress in Earth and Planetary Science, Journal Editorial Board Member, Society - Oct. 2017 - Present
日本学術会議地球惑星科学委員会IUGG分科会IAG小委員会, 委員長, Society - Oct. 2023 - Sep. 2029
日本学術会議 第26,27期, 連携会員, Government - Jul. 2023 - Jul. 2027
International Association of Geodesy, Executive Committee, Member-At-Large, Society - Oct. 2017 - Sep. 2023
日本学術会議 第24,25期, 連携会員, Government - Mar. 2021 - Jun. 2021
European Space Agency, Fringe 2021 Workshop, Science Committee Member, Others - Jul. 2016 - Dec. 2020
Earth Planets Space, Vice Editor-in-chief, Society - May 2016 - Mar. 2018
IAG-IASPEI2017, LOC member, Society - Nov. 2016 - Jun. 2017
European Space Agency, Fringe 2017 workshop, Scientific Committee, Society - Aug. 2007 - Jun. 2015
Journal of Geodesy, Editorial board member, Society - Jun. 2014 - Mar. 2015
European Space Agency, Fringe 2015 workshop, Scientific Committee, Society - Feb. 2011 - Sep. 2011
European Space Agency, Fringe 2011 workshop, Scientifc Comittee, Society - 2006 - 2010
日本火山学会, 編集委員, Society - 2010
日本測地学会, 評議員, Society - 2007 - 2008
日本測地学会, 評議員, Society - 2008
日本地球惑星科学連合, 代議員, Society - 2007
日本測地学会, 編集委員, Society
■Research activity information
Awards
- Jun. 2025, Springer Nature, Author Service Award 2025 (Progress in Earth and Planetary Science)
Masato Furuya - Mar. 2025, Earth Planets and Space, Highlighted Papers 2024
Can we explain the post-2015 absence of the Chandler wobble?
Ryuji Yamaguchi;Masato Furuya - Oct. 2024, The Geodetic Society of Japan, Tsuboi prize (Group award)
Boost-up of SAR-based Research in Japan
PIXEL (PALSAR Interferometry Consortium to Study our Evolving Land surface): Masato Furuya;Yosuke Aoki;Taku Ozawa;Akiko Tanaka;Yo Fukushima;Shinobu Ando;Youichiro Takada;Satoshi Okuyama;Yohei Kinoshita - May 2021, Volcanological society of Japan, Excellent paper award
Precursory ground deformation of the 2018 phreatic eruption on Iwo-Yama volcano, revealed by four-dimensional joint analysis of airborne and spaceborne InSAR, Earth Planets Space, 72, 1, doi:10.1186/ s40623-020-01280-5.
Shohei Narita;Taku Ozawa;Yosuke Aoki;Masanobu Shimada;Masato Furuya;Youichiro Takada;Makoto Murakami - 2010, ESPEC Environmental Research Award
Japan - 2007, International Association of Geodesy, Guy Bomford Prize
Masato Furuya - 2004, The Volcanology Society of Japan, Best Paper Award:
Mass Budget of the Magma Flow in the 2000 Volcano-Seismic Activity at Izu-Islands, Japan, Earth, Planets & Space, 55, 375-385, 2003.
Furuya, M.;S. Okubo;F. Kimata;R. Miyajima;I. Meilano;W. Sun;Y. Tanaka;T. Miyazaki, Japan - 2000, The Geodetic Society of Japan, The 8th Tsuboi Prize
Japan
Papers
- Decades‐Long Evolution of Post‐Fire Permafrost Deformation Detected by InSAR: Insights From Chronosequence in North Yukon
Zetao Cao, Masato Furuya
AGU Advances, 6, 4, American Geophysical Union (AGU), 22 Aug. 2025, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal, Abstract
Permafrost, a critical global cryospheric component, supports subarctic boreal forests but is frequently disturbed by wildfires, an important driver of permafrost degradation. Wildfires reduce vegetation, organic layers, and surface albedo, leading to active layer thickening and ground subsidence. Recent studies using interferometric synthetic aperture radar (InSAR) have confirmed the rapid and extensive post‐fire permafrost degradation, and have largely focused on short‐term impacts. However, the longer‐term post‐fire permafrost deformation, potentially persisting for decades, remains poorly understood due to limited data. Here, we applied InSAR in North Yukon to detect deformation signals across multiple fire scars in the past five decades. Using a chronosequence (space‐for‐time substitution) approach, we summarize a continuous trajectory of post‐fire permafrost evolution: (a) an initial degradation stage, characterized by abrupt subsidence up to 50 mm/year and gradually slowing over the first decade, with cumulative subsidence exceeding 100 mm locally; (b) an aggradation stage from approximately 15 to 30 years after fire, marked by ground uplift reaching 25 mm/year before gradually declining, compensating for the earlier subsidence; and (c) a stabilization stage beyond three to four decades, where permafrost nearly recovers to pre‐fire conditions with indistinguishable deformation between burned and unburned areas. Notably, the rarely‐reported uplift phase appears closely related to vegetation regeneration and fire‐greening feedback that provide thermal protection, suggesting a critical mechanism of permafrost recovery. These findings provide new insights into the resilience of boreal‐permafrost systems to wildfires and also underscore the importance of long‐term InSAR monitoring in understanding permafrost responses to wildfires under climate change., 42227546 - Can we estimate the period and quality-factor of the Chandler wobble using only the observed polar motion data?
Ryuji Yamaguchi, Masato Furuya
Earth, Planets and Space, 77, 1, Springer Science and Business Media LLC, 01 Jul. 2025, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal, Abstract
The clear ~ 6-year beat in the polar motion data has allowed us to consider the Chandler period (P) as ~ 1.2 years, albeit approximately, from solely the observed polar motion data. This has been made possible not only because the period of the beat can be explained by a combination of the periods of both annual wobble (AW) and Chandler wobble (CW), but also because the spectrum of excitation has been assumed to be flat around the resonant frequency. In contrast, substantial uncertainties persist in the assessment of its quality factor (Q), given the continuous observation of CW but the uncertainties surrounding its excitation sources. Nonetheless, two recent studies asserted that they could estimate both the P and Q or constrain the upper bound of Q only from the observed polar motion data. Here we point out that both studies have problems in their approaches and argue that we cannot optimize either P or Q without access to geophysical excitation data or their models.
Graphical Abstract - Fine structure of a daytime mid-latitude sporadic-E revealed by GNSS TEC, InSAR, and MAI
Tatsuya Fujimoto, Masato Furuya, Kosuke Heki
Earth, Planets and Space, 30 Oct. 2024, [Peer-reviewed], [Corresponding author]
English, Scientific journal - No deceleration signs in the permafrost ground subsidence four years after the 2019 fire in Northwest Territories, Canada
Zetao Cao, Masato Furuya
Environmental Research Letters, IOP Publishing, 09 Sep. 2024, [Peer-reviewed], [Last author]
English, Scientific journal, Abstract
The circum-arctic permafrost environment is often disturbed by wildfires but could also show resilience to these disturbances. However, the increased frequency and extent of wildfires, coupled with unprecedented hot weather, have introduced greater uncertainties in the post-fire permafrost dynamics. We need to address emerging questions, e.g., How will permafrost respond to the joint effect of hot anomalies and wildfires? To what extent will post-wildfire deformation evolve? How will permafrost resilience to wildfires vary? Utilizing Interferometric Synthetic Aperture Radar (InSAR) time series analysis, we investigated the post-wildfire ground deformation around a 2019 fire scar in the lower Mackenzie Valley, Northwest Territories, Canada, where dramatic heat anomalies and severe wildfires have been recorded in recent years. The resilience of permafrost to wildfires appears to be weakened by the continuous and rapid warming after the fire, as evidenced by the year-on-year acceleration in subsidence rates. Such acceleration was never reported by previous findings that typically observed deceleration in subsidence rates four to five years after wildfires. The deformation along the line of sight (LOS) of the satellite demonstrates significant permafrost degradation induced by wildfires and exacerbated by climate warming, and the cumulative subsidence was detected up to 25 cm in the LOS direction in the upland areas and up to 10 cm in the lowland areas four years after the fire. The difference in deformation magnitude could be attributed to local factors, including ground ice, topography, and vegetation. Our study highlights the increasingly severe threat to circum-arctic permafrost due to the combined effects of wildfires and extreme heat anomalies., 42227546 - Heavy Rain Episodes Identified by L-band InSAR and Limitations of Split-Spectrum Method in Indonesia
Naufal Setiawan, Masato Furuya
Geosfera Indonesia, 07 Apr. 2024, [Peer-reviewed], [Last author], ［Internationally co-authored］, [International Magazine]
Scientific journal - Can we explain the post-2015 absence of the Chandler wobble?
Ryuji Yamaguchi, Masato Furuya
Earth, Planets and Space, 76, 1, Springer Science and Business Media LLC, 02 Jan. 2024, [Peer-reviewed], [Last author]
English, Scientific journal, Abstract
Recent polar motion data do not show a 6-year beat and indicate the absence of the Chandler wobble (CW), whereas we could observe the 6-year beat even in the 1920-40 s when the CW amplitude was known to be smallest. As a free mode, the CW needs excitation one or more sources that were debated decades ago but are now attributed to the atmosphere, ocean, and possibly land water. Here, we show that the anomaly started in 2015, after which two independent estimates of the atmospheric CW excitation became persistently smaller than before. However, the estimates of the oceanic and land–water contributions are too large, suggesting improved estimates are needed. Taking advantage of the recent CW anomaly, we show that the quality factor of CW is not as high as 100 as previously preferred. Although the CW excitation processes have been assumed random, a termination of near-resonant processes would rather be consistent with the present findings.
Graphical Abstract - Special issue “20th anniversary issue: earth, planetary, and space science in the next decade”
Yasuo Ogawa, Nozomu Nishitani, Masato Furuya, Valerio Acocella, Hauke Hussmann
Earth, Planets and Space, 75, 1, Dec. 2023
Scientific journal - Transient Freeze‐Thaw Deformation Responses to the 2018 and 2019 Fires Near Batagaika Megaslump, Northeast Siberia
K. Yanagiya, M. Furuya, P. Danilov, G. Iwahana
Journal of Geophysical Research: Earth Surface, 128, 2, American Geophysical Union (AGU), 12 Feb. 2023, [Peer-reviewed], [Corresponding author]
Scientific journal - Post‐Seismic to Co‐Seismic Moment Ratios for the 2016 Moderate Earthquakes Along Chaman Fault
Masato Furuya, Fumiko Matsumoto
Geophysical Research Letters, 49, 1, American Geophysical Union (AGU), 29 Dec. 2021, [Peer-reviewed], [Lead author, Corresponding author]
English, Scientific journal - L-band Synthetic Aperture Radar: Current and future applications to Earth sciences
Yosuke Aoki, Masato Furuya, Francesco De Zan, Marie Pierre Doin, Michael Eineder, Masato Ohki, Tim J. Wright
Earth, Planets and Space, 73, 1, Dec. 2021
Scientific journal - Tropospheric dispersive phase anomalies during heavy rain detected by L-band InSAR and their interpretation
Naufal Setiawan, Masato Furuya
Earth, Planets and Space, 73, 1, Springer Science and Business Media LLC, Jul. 2021, [Peer-reviewed], [Last author]
English, Scientific journal,Abstract The split-spectrum method (SSM) can largely isolate and correct for the ionospheric contribution in the L-band interferometric synthetic aperture radar (InSAR). The standard SSM is performed on the assumption of only the first-order ionospheric dispersive effect, which is proportional to the total electron content (TEC). It is also known that during extreme atmospheric events, either originated from the ionosphere or in the troposphere, other dispersive effects do exist and potentially provide new insights into the dynamics of the atmosphere, but there have been few detection reports of such signals by InSAR. We apply L-band InSAR into heavy rain cases and examine the applicability and limitation of the standard SSM. Since no events such as earthquakes to cause surface deformation took place, the non-dispersive component is apparently attributable to the large amount of water vapor associated with heavy rain, whereas there are spotty anomalies in the dispersive component that are closely correlated with the heavy rain area. The ionosonde and Global Navigation Satellite System (GNSS) rate of total electron content index (ROTI) map both show little anomalies during the heavy rain, which suggests few ionospheric disturbances. Therefore, we interpret that the spotty anomalies in the dispersive component of the standard SSM during heavy rain are originated in the troposphere. While we can consider two physical mechanisms, one is runaway electron avalanche and the other is the dispersive effect due to rain, comparison with the observations from the ground-based lightning detection network and rain gauge data, we conclude that the rain dispersive effect is spatiotemporally favorable. We further propose a formulation to examine if another dispersive phase than the first-order TEC effect is present and apply it to the heavy rain cases as well as two extreme ionospheric sporadic-E events. Our formulation successfully isolates the presence of another dispersive phase during heavy rain that is in positive correlation with the local rain rate. In comparison with other dispersive phases during Sporadic-E episodes, the dispersive heavy rain phases seem to have the same order of magnitude with the ionospheric higher order effects., 11969563 - Rapidly changing glaciers, ocean and coastal environments, and their impact on human society in the Qaanaaq region, northwestern Greenland
Shin Sugiyama, Naoya Kanna, Daiki Sakakibara, Takuto Ando, Izumi Asaji, Ken Kondo, Yefan Wang, Yoshiki Fujishi, Shungo Fukumoto, Evgeniy Podolskiy, Yasushi Fukamachi, Minori Takahashi, Sumito Matoba, Yoshinori Iizuka, Ralf Greve, Masato Furuya, Kazutaka Tateyama, Tatsuya Watanabe, Shintaro Yamasaki, Atsushi Yamaguchi, Bungo Nishizawa, Kohei Matsuno, Daiki Nomura, Yuta Sakuragi, Yoshimasa Matsumura, Yoshihiko Ohashi, Teruo Aoki, Masashi Niwano, Naotaka Hayashi, Masahiro Minowa, Guillaume Jouvet, Eef van Dongen, Andreas Bauder, Martin Funk, Anders Anker Bjørk, Toku Oshima
Polar Science, 27, 100632, 100632, Elsevier BV, Mar. 2021, [Peer-reviewed]
Scientific journal - Precursory ground deformation of the 2018 phreatic eruption on Iwo-Yama volcano, revealed by four-dimensional joint analysis of airborne and spaceborne InSAR
Shohei Narita, Taku Ozawa, Yosuke Aoki, Masanobu Shimada, Masato Furuya, Youichiro Takada, Makoto Murakami
Earth, Planets and Space, 72, 1, Springer Science and Business Media LLC, Oct. 2020, [Peer-reviewed]
English, Scientific journal - Coseismic and Postseismic Crustal Deformation Associated With the 2016 Kumamoto Earthquake Sequence Revealed by PALSAR‐2 Pixel Tracking and InSAR
Yuji Himematsu, Masato Furuya
Earth and Space Science, 7, 10, American Geophysical Union (AGU), Oct. 2020, [Peer-reviewed]
Scientific journal - Rift-parallel block-like motion of the graben floor during the 2005–2010 Afar rifting episode
Yuji Himematsu, Masato Furuya
Tectonophysics, 791, 228571, 228571, Elsevier BV, Sep. 2020, [Peer-reviewed]
Scientific journal - Post‐wildfire surface deformation near Batagay, Eastern Siberia, detected by L‐band and C‐band InSAR
Kazuki Yanagiya, Masato Furuya
Journal of Geophysical Research: Earth Surface, 125, 7, American Geophysical Union ({AGU}), 09 Jun. 2020, [Peer-reviewed]
Scientific journal - Icecap and Subglacial Crustal Deformation Inferred From SAR Pixel Tracking: The 2014 Dike Intrusion Episode in the Bárðarbunga Volcanic System, Iceland
Yuji Himematsu, Freysteinn Sigmundsson, Masato Furuya
Journal of Geophysical Research: Solid Earth, 124, 9, 9940, 9955, American Geophysical Union (AGU), Sep. 2019, [Peer-reviewed]
English, Scientific journal, Bárðarbunga is an active volcano beneath the Vatnajökull icecap in Iceland, where a subglacial dike intrusion occurred in 2014. This area has been studied with interferometric synthetic aperture radar, an important geodetic method that measures crustal deformation; however, ice/snow cover on volcanoes impedes the mapping of crustal deformation because of decorrelation problems. Previous geodetic observations have reported deformation signals at ice‐free regions of a major dike formed in 2014 in the Bárðarbunga volcanic system, but direct observations of the subglacial crustal deformation associated with the dike intrusion have been limited. We applied a pixel tracking approach to various satellite synthetic aperture radar (SAR) data over the northern part of the Vatnajokull icecap and the Holuhraun plain. The pixel tracking data revealed not only crustal deformation fields in the ice‐free region of the magma intrusion, which covers only about 20% of the entire length of dike, but also icecap surface movements over the subglacial part of the dike in the ablation area of the Vatnajökull icecap. Signals above the icecap, suggesting subsidence due to subglacial graben formation, are consistent with the dike propagation path inferred from seismicity during the episode. By subtracting the scaled pre‐diking signals from the co‐diking signals, we corrected for the steady‐state icecap flow signals to derive the subglacial crustal deformations. We showed that the inferred subglacial crustal deformation signals can significantly contribute to the improvement of dike opening/faulting distributions. Applying the pixel tracking to satellite images will enable mapping subglacial crustal deformation in the case of subglacial volcanic activity. - Report on the 27th IUGG general assembly and the 1st executive committee meeting of IAG
Toshimichi Otsubo, Masato Furuya, Takuya Nishimura
Journal of the Geodetic Society of Japan, 65, 1, 74, 77, Geodetic Society of Japan, 2019
English, International conference proceedings - Interannual modulation of seasonal glacial velocity variations in the Eastern Karakoram detected by ALOS-1/2 data
Muhammad Usman, Masato Furuya
Journal of Glaciology, 64, 245, 465, 476, 01 Jun. 2018, [Peer-reviewed]
English, Scientific journal - Surface deformation and source modeling of Ayaz-Akhtarma mud volcano, Azerbaijan, as detected by ALOS/ALOS-2 InSAR
Iio, Kento, Furuya, Masato
Progress in Earth and Planetary Science, 5, 61, 2018, [Peer-reviewed]
English, Scientific journal - Special issue “GNSS and SAR Technologies for Atmospheric Sensing”
Tsuda, T., Realini, E., Shoji, Y., Saito, A., Yabuki, M., Furuya, M.
Earth, Planets and Space, 70, 1, 2018
Scientific journal - Midlatitude sporadic-E episodes viewed by L-band split-spectrum InSAR
Masato Furuya, Takato Suzuki, Jun Maeda, Kosuke Heki
Earth, Planets and Space, 69, 175, Dec. 2017, [Peer-reviewed]
English, Scientific journal - Report on the fringe 2017
Furuya, M.
Journal of the Geodetic Society of Japan, 63, 2, 2017
Scientific journal - Seasonal and inter-annual variability in velocity and frontal position of Siachen Glacier (Eastern Karakorum) using multi-satellite data
USMAN Muhammad, FURUYA Masato, SAKAKIBARA Daiki, ABE Takahiro
Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research, 2017, 186, 186, The Japanese Society of Snow and Ice / Japan Society for Snow Engineering, 2017
Japanese - Spatial and Temporal Variations of Glacier Flow Velocities at Pio XI Glacier, the Southern Patagonian Icefield, Detected from Synthetic Aperture Rader data
Hata Shuntaro, Furuya Masato
Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research, 2017, 187, 187, The Japanese Society of Snow and Ice / Japan Society for Snow Engineering, 2017
Japanese - ROCK GLACIERS IN THE BHUTAN HIMALAYAS
FUKUI Kotaro, FUJITA Koji, TSHERING Phuntsho, FURUYA Masato
Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research, 2017, 89, 89, The Japanese Society of Snow and Ice / Japan Society for Snow Engineering, 2017
Japanese - Localized Delay Signals Detected by Synthetic Aperture Radar Interferometry and Their Simulation by WRF 4DVAR
Youhei Kinoshita, Masato Furuya
Sola, 13, 0, 79, 84, 2017, [Peer-reviewed]
English, Scientific journal - Experimental Observations of Two Mountain Glaciers on the Eastern Slope of Mt. Tsurugi by Pi-SAR2 Airborne SAR
Masato Furuya
Bulletin of Glaciological Research, 35, 7, 17, 2017, [Peer-reviewed], [Domestic magazines]
English, Scientific journal - Erratum to: Fault source model for the 2016 Kumamoto earthquake sequence based on ALOS-2/PALSAR-2 pixel-offset data: Evidence for dynamic slip partitioning (Earth, Planets and Space (2016) 68 (169) DOI: 10.1186/s40623-016-0545-7)
Yuji Himematsu, Masato Furuya
Earth, Planets and Space, 68, 1, Springer Berlin Heidelberg, 01 Dec. 2016, [Peer-reviewed]
English, Scientific journal - Dynamics of surge-type glaciers in Alaska-Yukon revealed by Synthetic Aperture Radar
ABE Takahiro, FURUYA Masato
Seppyo, 78, 6, 425, 438, 日本雪氷学会, Nov. 2016, [Peer-reviewed]
Japanese, Scientific journal - Fault source model for the 2016 Kumamoto earthquake sequence based on ALOS-2/PALSAR-2 pixel-offset data: evidence for dynamic slip partitioning (EPSP-D-16-00163)
Himematsu, Y., Furuya, M.
Earth Planets and Space, 68, 169, 2016, [Peer-reviewed]
English, Scientific journal - Imaging the midlatitude sporadic E plasma patches with a coordinated observation of spaceborne InSAR and GPS total electron content
Maeda, Jun, Suzuki, Takato, Furuya, Masato, Heki, Kosuke
Geophysical Research Letters, 43, 4, 1419, 1425, 2016, [Peer-reviewed]
English, Scientific journal - Brief Communication: Twelve-year cyclic surging episodes at Donjek Glacier in Yukon, Canada
Abe, Takahiro, Furuya, Masato, Sakakibara, Daiki
Cryosphere, 10, 4, 1427, 1432, 2016, [Peer-reviewed]
English, Scientific journal - Brief Communication: Twelve-year cyclic surging episode at Donjek Glacier in Yukon, Canada
T. Abe, M. Furuya, D. Sakakibara
The Cryosphere Discuss, 9, 5943, 5955, Nov. 2015, [Peer-reviewed]
English, Scientific journal - Aseismic strike–slip associated with the 2007 dike intrusion episode in Tanzania
Yuji Himematsu, Masato Furuya
Tectonophysics, 656, 52, 60, Aug. 2015, [Peer-reviewed]
English, Scientific journal - Report on 26th IUGG General Assembly 2015
Furuya, M.
Journal of the Geodetic Society of Japan, 61, 3, 2015
Scientific journal - Twelve-year cyclic surge-like event at Donjek Glacier in Yukon, Canada
Abe Takahiro, Furuya Masato, Sakakibara Daiki
Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research, 2015, 7, 7, The Japanese Society of Snow and Ice / Japan Society for Snow Engineering, 2015
Japanese - Distribution and dynamics of surge-type glaciers in West Kunlun Shan, NW Tibet, China
Yasuda Takatoshi, Furuya Masato
Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research, 2015, 188, 188, The Japanese Society of Snow and Ice / Japan Society for Snow Engineering, 2015
Japanese - Ice speed mapping in Alaska/Yukon derived from ALOS-2/PALSAR-2 data
Abe Takahiro, Furuya Masato
Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research, 2015, 8, 8, The Japanese Society of Snow and Ice / Japan Society for Snow Engineering, 2015
Japanese - Dynamics of surge-type glaciers in West Kunlun Shan, Northwestern Tibet
Yasuda, Takatoshi, Furuya, Masato
Journal of Geophysical Research-Earth Surface, 120, 11, 2393, 2405, 2015, [Peer-reviewed]
English, Scientific journal - Complex faulting in the Quetta Syntaxis: fault source modeling of the October 28, 2008 earthquake sequence in Baluchistan, Pakistan, based on ALOS/PALSAR InSAR data
Usman, Muhammad, Furuya, Masato
Earth Planets and Space, 67, 2015, [Peer-reviewed]
English, Scientific journal - Winter speed-up of quiescent surge-type glaciers in Yukon, Canada
Abe, T., Furuya, M.
Cryosphere, 9, 3, 1183, 1190, 2015, [Peer-reviewed]
English, Scientific journal - Winter speed-up of quiescent surge-type glaciers in Yukon, Canada
T. Abe, M. Furuya
The Cryosphere Discuss, 8, 2611, 2635, May 2014, [Peer-reviewed]
English, Scientific journal - InSAR observation and numerical modeling of the water vapor signal during a heavy rain: A case study of the 2008 Seino event, central Japan
Youhei Kinoshita, Masanobu Shimada, Masato Furuya
Geophysical Research Letters, 40, 17, 4740, 4744, 06 Sep. 2013, [Peer-reviewed]
English, Scientific journal - Are numerical weather model outputs helpful to reduce tropospheric delay signals in InSAR data?
Furuya, Masato, Hobiger, Thomas, Ichikawa, Ryuichi, Kinoshita, Youhei
Journal of Geodesy, 87, 3, 267, 277, 2013, [Peer-reviewed]
English, Scientific journal - Nonplanar Fault Source Modeling of the 2008 M-w 6.9 Iwate-Miyagi Inland Earthquake in Northeast Japan
Abe, Takahiro, Furuya, Masato, Takada, Youichiro
Bulletin of the Seismological Society of America, 103, 1, 507, 518, 2013, [Peer-reviewed]
English, Scientific journal - Short-term glacier velocity changes at West Kunlun Shan, Northwest Tibet, detected by Synthetic Aperture Radar data
Furuya, Masato, Yasuda, Takatoshi
Remote Sensing of Environment, 128, 87, 106, 2013, [Peer-reviewed]
English, Scientific journal - Perspectives of Crustal Deformation Research in Japan with Synthetic Aperture Radar
Hashimoto Manabu, Furuya Masato, Ozawa Taku, Fukushima Yo
Journal of the Geodetic Society of Japan, 59, 3, 119, 132, The Geodetic Society of Japan, 2013
Japanese, Synthetic aperture radar (SAR) has been widely used in crustal deformation studies all over the world. Especially the Japanese Advanced Land Observing Satellite (ALOS) contributed so much to the studies of large earthquakes, volcanic eruptions, landslides and other phenomena, and Japanese researchers presented many remarkable results in international journals and conferences. Studies with SAR, however, depend on the environment including satellites, software, data distribution etc. International research community is taking a step forward earlier than the Japanese community, by establishing research alliances between several disciplines. New techniques are frequently proposed and discussed in several international meetings. Data and software are widely and freely distributed in the international research community. Although the ALOS-2 will be launched in the near future and Japanese researchers may have privileges on the access to data, it is important to discuss the strategy that do not heavily depend on ALOS-2. Collaboration among researchers in related fields of SAR technologies and earth sciences is indispensable to achieve the international competition in research. It is also important for Japanese researchers to present the potential and attractiveness of SAR studies to young students. - InSAR observation and numerical modeling of the water vapor signal during 2008 Seino heavy rain Event, central Japan
Youhei Kinoshita, Masanobu Shimada, Masato Furuya
CONFERENCE PROCEEDINGS OF 2013 ASIA-PACIFIC CONFERENCE ON SYNTHETIC APERTURE RADAR (APSAR), 175, +, 2013, [Peer-reviewed]
English, International conference proceedings - Interseismic deformation and creep along the central section of the North Anatolian Fault (Turkey): InSAR observations and implications for rate-and-state friction properties
Fialko, Y., Furuya, M., Kaneko, Y., Sandwell, D. T., Tong, X.
Journal of Geophysical Research-Solid Earth, 118, 1, 316, 331, American Geophysical Union, 2013, [Peer-reviewed]
English, Scientific journal, We present high-resolution measurements of interseismic deformation along the central section of the North Anatolian Fault (NAF) in Turkey using interferometric synthetic aperture radar data from the Advanced Land Observing Satellite and Envisat missions. We generated maps of satellite line-of-sight velocity using five ascending Advanced Land Observing Satellite tracks and one descending Envisat track covering the NAF between 31.2 degrees E and 34.3 degrees E. The line-of-sight velocity reveals discontinuities of up to similar to 5 mm/yr across the Ismetpasa segment of the NAF, implying surface creep at a rate of similar to 9 mm/yr; this is a large fraction of the inferred slip rate of the NAF (21-25 mm/yr). The lateral extent of significant surface creep is about 75 km. We model the inferred surface velocity and shallow fault creep using numerical simulations of spontaneous earthquake sequences that incorporate laboratory-derived rate and state friction. Our results indicate that frictional behavior in the Ismetpasa segment is velocity strengthening at shallow depths and transitions to velocity weakening at a depth of 3-6 km. The inferred depth extent of shallow fault creep is 5.5-7 km, suggesting that the deeper locked portion of the partially creeping segment is characterized by a higher stressing rate, smaller events, and shorter recurrence interval. We also reproduce surface velocity in a locked segment of the NAF by fault models with velocity-weakening conditions at shallow depth. Our results imply that frictional behavior in a shallow portion of major active faults with little or no shallow creep is mostly velocity weakening. Citation: Kaneko, Y., Y. Fialko, D. T. Sandwell, X. Tong, and M. Furuya (2013), Interseismic deformation and creep along the central section of the North Anatolian Fault (Turkey): InSAR observations and implications for rate-and-state friction properties, J. Geophys. Res. Solid Earth, 118, 316-331, doi: 10.1029/2012JB009661. - Surface velocities and ice-front positions of eight major glaciers in the Southern Patagonian Ice Field, South America, from 2002 to 2011
Minami Muto, Masato Furuya
Remote Sensing of Environment, 139, 50, 59, 2013, [Peer-reviewed]
English, Scientific journal - Constraining ice mass loss from Jakobshavn Isbrae (Greenland) using InSAR-measured crustal uplift
Lin Liu, John Wahr, Ian Howat, Shfaqat Abbas Khan, Ian Joughin, Masato Furuya
Geophysical Journal International, 188, 3, 994, 1006, 09 Jan. 2012, [Peer-reviewed]
English, Scientific journal - Dynamics of surging glaciers in Yukon detected by ALOS/PALSAR
ABE TAKAHIRO, FURUYA MASATO
Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research, 2012, 5, 5, The Japanese Society of Snow and Ice / Japan Society for Snow Engineering, 2012
Japanese - Glacier Surge in the West Kunlun Shan, NW Tibet, Detected by Synthetic Aperture Radar
Yasuda Takatoshi, Furuya Masato
Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research, 2012, 2, 2, The Japanese Society of Snow and Ice / Japan Society for Snow Engineering, 2012
Japanese - Spatial and Temporal Changes of Glacier Flow Velocities in Southern Patagonia Icefield, Inferred from Synthetic Aperture Radar
Muto Minami, Furuya Masato
Summaries of JSSI and JSSE Joint Conference on Snow and Ice Research, 2012, 6, 6, The Japanese Society of Snow and Ice / Japan Society for Snow Engineering, 2012
Japanese - Images from ALOS of the March 2011 Tohoku Earthquake
Mikio Tobita, Masanobu Shimada Manabu Hashimoto, Yo Fukushima, Youichiro Takada, Taku Ozawa, Satoshi Okuyama, Takahiro Abe, Masato Furuya
Space Research Today, 181, 17, 19, Elsevier BV, Aug. 2011, [Invited]
English, Scientific journal - Post-seismic Surface Deformation Following the 2008 Iwate-Miyagi Nairiku Earthquake Detected by ALOS/PALSAR
TAKADA Youichiro, KOBAYASHI Tomokazu, FURUYA Masato, MURAKAMI Makoto
Journal of the Geodetic Society of Japan, 57, 4, 181, 193, The Geodetic Society of Japan, 2011, [Peer-reviewed]
Japanese, We detected post-seismic surface deformation following the 2008 Iwate-Miyagi Nairiku Earthquake (2008 June 14 JST, M6.8) by interferometric synthetic aperture radar (InSAR) analysis using ALOS/PALSAR data. The ascending interferograms indicate ∼8 cm of length increase in radar line-of-sight (LOS) to the east of Mt. Kurikoma (KRK), and decreases in it to the south of KRK and around Mt. Amadamori (AMM). The descending interferograms indicate ~4 cm of length increase in LOS to the east of Mt. Kunimiyama (KNM), and around AMM. We found that a west-dipping high-angle reverse fault roughly explains overall pattern of the length changes in LOS (ΔLOS) to the east of KNM. We demonstrated that ALOS/PALSAR has a strong ability to detect surface deformation lurking in such a vast mountainous area. - The 2008 Yutian normal faulting earthquake (Mw 7.1), NW Tibet: Non-planar fault modeling and implications for the Karakax Fault
Furuya, Masato, Yasuda, Takatoshi
Tectonophysics, 511, 3-4, 125, 133, 2011, [Peer-reviewed]
English, Scientific journal - Sar interferometry
Furuya, M.
Encyclopedia of Earth Sciences Series, Part 5, Encyclopedia of Earth Sciences Series, 2011
Scientific journal - A3-12 Monitoring of Surface Unrest Associated with 2011 Off-Pacific Tohoku EQ Using ALOS PALSAR : Case Study for Applications to Monitor Precursors of Edifice Collapse of Volcanoes
Murakami Makoto, Okuyama Satoshi, Furuya Masato, Abe Takahiro
PROGRAMME AND ABSTRACTS THE VOLCANOLOGICAL SOCIETY OF JAPAN, 2011, 55, 55, The Volcanological Society of Japan, 2011
Japanese - Gravity changes observed between 2004 and 2009 near the Tokai slow-slip area and prospects for detecting fluid flow during future slow-slip events
Yoshiyuki Tanaka, Aitaro Kato, Takayuki Sugano, Guangyu Fu, Xinlin Zhang, Masato Furuya, Wenke Sun, Shuhei Okubo, Shigeo Matsumoto, Masaki Honda, Yasuhiro Sugawara, Isao Ueda, Masaaki Kusaka, Misao Ishihara
EARTH PLANETS AND SPACE, 62, 12, 905, 913, 2010, [Peer-reviewed]
English, Scientific journal - Fault Source Modeling of the 2008 Wenchuan Earthquake Based on ALOS/PALSAR Data
Furuya, M., Kobayashi, T., Murakami, M., Takada, Y.
Bulletin of the Seismological Society of America, 100, 5B, 2750, 2766, 2010, [Peer-reviewed]
English, Scientific journal - PALSAR InSAR Observation and Modeling of Crustal Deformation Due to the 2007 Chuetsu-Oki Earthquake in Niigata, Japan
M. Furuya, Y. Takada, Y. Aoki
GRAVITY, GEOID AND EARTH OBSERVATION, 135, 679, 687, 2010, [Peer-reviewed]
English, International conference proceedings - On the importance of accurately ray-traced troposphere corrections for Interferometric SAR data
Furuya, M., Hobiger, T., Ichikawa, R., Kinoshita, Y., Kondo, T., Koyama, Y., Shimizu, S.
Journal of Geodesy, 84, 9, 537, 546, 2010, [Peer-reviewed]
English, Scientific journal - Aseismic slip during the 1996 earthquake swarm in and around the Onikobe geothermal area, NE Japan
Furuya, M., Takada, Y.
Earth and Planetary Science Letters, 290, 3-4, 302, 310, 2010, [Peer-reviewed]
English, Scientific journal - Gravity changes observed between 2004 and 2009 near the Tokai slow-slip area and prospects for detecting fluid flow during future slow-slip events
Yoshiyuki Tanaka, Aitaro Kato, Takayuki Sugano, Guangyu Fu, Xinlin Zhang, Masato Furuya, Wenke Sun, Shuhei Okubo, Shigeo Matsumoto, Masaki Honda, Yasuhiro Sugawara, Isao Ueda, Masaaki Kusaka, Misao Ishihara
Earth, Planets and Space, 62, 12, 905, 913, Springer Berlin, 2010, [Peer-reviewed]
English, Scientific journal - Locations and types of ruptures involved in the 2008 Sichuan earthquake inferred from SAR image matching
Tomokazu Kobayashi, Youichiro Takada, Masato Furuya, Makoto Murakami
GEOPHYSICAL RESEARCH LETTERS, 36, Apr. 2009, [Peer-reviewed]
English, Scientific journal - Coseismic displacement due to the 2008 Iwate-Miyagi Nairiku earthquake detected by ALOS/PALSAR: preliminary results
Furuya, Masato, Kobayashi, Tomokazu, Murakami, Makoto, Takada, Youichiro
Earth Planets and Space, 61, 4, e9, e12, 2009, [Peer-reviewed]
English, Scientific journal - Coseismic deformation due to the 2007 Chuetsu-oki earthquake (M(w)=6.8)
Aoki, Y., Furuya, M., Kato, T.
Earth Planets and Space, 60, 11, 1075, 1080, 2008, [Peer-reviewed]
Scientific journal - Slow earthquake in Afghanistan detected by InSAR
Furuya, M., Satyabala, S. P.
Geophysical Research Letters, 35, 6, L06309, 2008, [Peer-reviewed]
English, Scientific journal - Japanese L-Band Radar Improves Surface Deformation Monitoring
Masanobu Shimada, Taku Ozawa, Yo Fukushima, Masato Furuya, Ake Rosenqvist
Eos, Transactions American Geophysical Union, 89, 31, 277, 277, American Geophysical Union (AGU), 2008
Scientific journal - B21 Ground deformation at Suwanose-jima volcano as viewed from ALOS/PALSAR InSAR
Oikawa Jun, Aoki Yosuke, Furuya Masato, Iguchi Masato
PROGRAMME AND ABSTRACTS THE VOLCANOLOGICAL SOCIETY OF JAPAN, 2008, 73, 73, The Volcanological Society of Japan, 2008
Japanese - Coseismic deformation due to the 2007 Chuetsu-oki earthquake (Mw = 6.8)
Yosuke Aoki, Masato Furuya, Teruyuki Kato
Earth, Planets and Space, 60, 11, 1075, 1080, Springer Berlin, 2008, [Peer-reviewed]
English, Scientific journal - Report on the XXIV General Assemblies of IUGG and IAG in Perugia
OKUBO Shuhei, SHIMADA Seiichi, FUKUDA Yoichi, TAMURA Yoshiaki, MUNEKANE Hiroshi, FURUYA Masato, SAGIYA Takeshi
Journal of the Geodetic Society of Japan, 53, 3, 207, 217, The Geodetic Society of Japan, 25 Sep. 2007
Japanese - Application of Interferometric Point Target Analysis to Izu-Oshima Volcano, Japan
FURUYA M.
Proceedings of Envisat Symposium 2007, 462406, 2007 - Active salt tectonics in the Needles District, Canyonlands (Utah) as detected by interferometric synthetic aperture radar and point target analysis: 1992-2002
Furuya, M., Mueller, K., Wahr, J.
Journal of Geophysical Research-Solid Earth, 112, B6, B06418, 2007, [Peer-reviewed]
English, Scientific journal - InSAR: A New Trend in Crustal Deformation Measurement
Masato Furuya
Journal of Geodetic Society of Japan, 52, 4, 225, 243, The Geodetic Society of Japan, 2006, [Peer-reviewed]
Japanese, Interferometric Synthetic Aperture Radar (InSAR) provides us with images of crustal de formation with unprecedented spatial resolution. Its measurement precision is comparable to ground-based space geodetic techniques. Here I review how SAR data is acquired and proc essed to generate InSAR images. First, I describe in detail how raw SAR signal data are proc essed to generate geophysically interpretable image called single look complex (SLC) data. After introducing an image co-registration (matching) technique, I describe a principle of InSAR image generation, actual processing steps, and how to interpret them with potential issues to overcome. I also discuss interferometric coherence, which is another important concept that should be kept in mind. A couple of recent new applications results are explained, some which could not be obtained unless SAR data acqusition continued almost a decade. Further, new analysis techniques, i.e., permanent scatterer (PS) InSAR and ScanSAR, are briefly introduced. Finally, I discuss how promising the newly acquired L-band SAR data by Advanced Land Observation Satellite (ALOS) is for crustal deformation measurement. - B21 Gravity Changes after the 2000 Eruption of Mt. Usu(THE VOLCANOLOGICAL SOCIETY OF JAPAN 2006 FALL MEETING)
Oshma H., Maekawa T., Ueki S., Furuya M., Matsumoto S., Ueda H., Ozawa T., Watanabe A.
PROGRAMME AND ABSTRACTS THE VOLCANOLOGICAL SOCIETY OF JAPAN, 2006, 77, 77, The Volcanological Society of Japan, 2006
Japanese - On the damping term in the polar motion equation
FURUYA M.
Proc. Workshop : Forcing of polar motion in the Chandler frequency band : a contribution to understanding interannual climate variations, Cahiers du Centre Europeen de Geodynamique et de Seismologie, Walferdange, Luxembourg, 2005, 24, 57, 59, 2005, [Peer-reviewed] - Water level changes at an ice-dammed lake in west Greenland inferred from InSAR data
Furuya, M., Wahr, J. M.
Geophysical Research Letters, 32, 14, L14501, 2005, [Peer-reviewed]
English, Scientific journal - Quasi-static thermoelastic deformation in an elastic half-space: theory and application to InSAR observations at Izu-Oshima volcano, Japan
Furuya, M.
Geophysical Journal International, 161, 1, 230, 242, 2005, [Peer-reviewed]
English, Scientific journal - B07 Quasi-static Thermoclastic Deformation Theory and Its Application An Analytical Model for Post-cruptive Crustal Deformation(THE VOLCANOLOGICAL SOCIETY OF JAPAN 2005 FALL MEETING)
Furuya Masato
PROGRAMME AND ABSTRACTS THE VOLCANOLOGICAL SOCIETY OF JAPAN, 2005, 63, 63, The Volcanological Society of Japan, 2005
English - Localized deformation at Miyakejima volcano based on JERS-1 radar interferometry: 1992-1998
M Furuya
GEOPHYSICAL RESEARCH LETTERS, 31, 5, L5605, Mar. 2004, [Peer-reviewed]
English, Scientific journal - Spatiotemporal gravity changes at Miyakejima Volcano, Japan: Caldera collapse, explosive eruptions and magma movement
M Furuya, S Okubo, W Sun, Y Tanaka, J Oikawa, H Watanabe, T Maekawa
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH, 108, B4, 2219, Apr. 2003
English, Scientific journal - 桜島火山における絶対重力測定（1998年〜2002年）
京都大学防災研究所年報, 46B, 827, 833, 2003 - Mass budget of the magma flow in the 2000 volcano-seismic activity at Izu-islands, Japan
M Furuya, S Okubo, F Kimata, R Miyajima, Meilano, I, W Sun, Y Tanaka, T Miyazaki
EARTH PLANETS AND SPACE, 55, 7, 375, 385, 2003
English, Scientific journal - 2000年有珠山噴火活動の時定数
火山, 47, 5, 587, 594, 2002 - Continuous Monitoring of Absolute Gravity at Miyakejima Volcano Part 3
Furuya M., Okubo S., Sun W., Watanabe H., Matsumoto S.
PROGRAMME AND ABSTRACTS THE VOLCANOLOGICAL SOCIETY OF JAPAN, 2002, 113, 113, The Volcanological Society of Japan, 2002
Japanese - Co-Seismic Crustal Deformation Detected by DinSAR : 1996 Earthquakes in Onikobe Region
AOKI Shumpei, FURUYA Masato, KOBAYASHI Shigeki, OKUBO Shuhei
PROGRAMME AND ABSTRACTS THE VOLCANOLOGICAL SOCIETY OF JAPAN, 2002, 110, 110, The Volcanological Society of Japan, 2002
Japanese - 2000年有珠山噴火活動の重力測定
北海道大学地球物理学研究報告, 64, 81, 90, 2001 - 桜島の火山活動に伴う重力変化と絶対重力測定
月刊地球, 23, 8, 578, 582, 2001 - Inland Flexure due to ocean tide loading; A possible detection by satellite radar interferometry at Korean peninsula
CEOS SAR Workshop 2001 Proceedings, 25, 28, 2001 - Deciphering Excitation Sources of Polar Motion by Earth System Scientific Approach
Masato Furuya
journal of the geodetic society of japan, 47, 3, 701, 710, 2001
English, Scientific journal - 重力の時空間変化でとらえた三宅島2000年火山活動におけるカルデラ形成過程
地学雑誌, 110, 2, 217, 225, 2001 - Caldera Formation Process during the Miyakejima 2000 Volcanic Activity Detected by Spatio-temporal Gravity Changes
Masato FURUYA, Shuhei OKUBO, Yoshiyuki TANAKA, Wenke SUN, Hidefumi WATANABE, Jun OIKAWA, Tokumitsu MAEKAWA
Journal of Geography (Chigaku Zasshi), 110, 2, 217, 225, Tokyo Geographical Society, 2001
Scientific journal - Continuous Monitoring of Absolute Gravity at Miyakejima Volcano, Japan, 2001
Furuya M., Okubo S., Sun W., Yamanaka Y., Oikawa J., Watanabe H.
PROGRAMME AND ABSTRACTS THE VOLCANOLOGICAL SOCIETY OF JAPAN, 2001, 22, 22, The Volcanological Society of Japan, 2001
Japanese - Comparison of site velocities measured by VLBI and GPS in the key stone project network
Y Koyama, R Ichikawa, T Kondo, N Kurihara, Y Takahashi, T Yoshino, K Sebata, M Furuya
TOWARDS AN INTEGRATED GLOBAL GEODETIC OBSERVING SYSTEM (IGGOS), 120, 158, 160, 2000
English, International conference proceedings - A New Remote Sensing Technique of Fluid Mass Distribution : Satellite Gravimetry and Its Role in the Next Generation
Furuya Masato, Naito Isao
天気, 47, 1, 347, 355, 日本気象学会, 2000
Japanese - Strain Field inferred from Keystone VLBI Network
Proceedings of GEMSTONE workshop, 265, 270, 1999 - Routine Observation Results of the KSP VLBI Network
Journal of Communication Research Laboratory, 46, 1, 159, 164, 1999 - Effect of the Pacific Ocean on the Earth's seasonal wobble inferred from National Center for Environmental Prediction ocean analysis data
M Furuya, Y Hamano
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH, 103, B5, 10131, 10140, May 1998, [Peer-reviewed]
English, Scientific journal - Evaluation of repeatability of baseline lengths in the VLBI network around the Tokyo metropolitan area
T Kondo, N Kurihara, A Koyama, M Sekido, R Ichikawa, T Yoshino, J Amagai, K Sebata, M Furuya, Y Takahashi, H Kiuchi, A Kaneko
GEOPHYSICAL RESEARCH LETTERS, 25, 7, 1047, 1050, Apr. 1998
English, Scientific journal - Importance of wind for the excitation of Chandler wobble as inferred from wobble domain analysis
M Furuya, Y Hamano, Naito, I
JOURNAL OF PHYSICS OF THE EARTH, 45, 3, 177, 188, 1997
English, Scientific journal - Estimation of period and Q of the Chandler wobble
M Furuya, BF Chao
GEOPHYSICAL JOURNAL INTERNATIONAL, 127, 3, 693, 702, Dec. 1996
English, Scientific journal - Quasi-periodic wind signal as a possible excitation of Chandler wobble
M Furuya, Y Hamano, Naito, I
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH, 101, B11, 25537, 25546, Nov. 1996, [Peer-reviewed]
English, Scientific journal - Quasi-periodic wind signal as a possible excitation of Chandler wobble
Furuya, M., Hamano, Y., Naito, I.
Journal of Geophysical Research-Solid Earth, 101, B11, 1996
Scientific journal
Other Activities and Achievements
- Boost-up of SAR-based Research in Japan by PIXEL （PALSAR Interferometry Consortium to Study our Evolving Land surface）
Masato Furuya, Yosuke Aoki, Taku Ozawa, Akiko Tanaka, Yo Fukushim, Shinobu Ando, Youichiro Takad, Satoshi Okuyam, Yohei Kinoshi, Journal of Geodetic Society of Japan, 71, 28, 33, 11 Oct. 2025, [Peer-reviewed], [Invited], [Lead author, Corresponding author]
Japanese, Introduction scientific journal - 国際測地学協会2021 年学術総会（北京/ オンライン）報告
古 屋 正 人, 宮 原 伐折羅, 渡 邉 俊, 一, 日 置 幸 介, 大 坪 俊, 通, 福 田 洋一, 市 川 隆 一, 田 中 愛, 幸, 松 尾 功, 測地学会誌, 67, 40, 45, Dec. 2021
Japanese, Meeting report - Recent variation in Ice Speed and Ice-front Position of Pio XI Glacier, Southern Patagonia Icefield
Hata, S, S. Sugiyama, M. Furuya, Annual Report on Snow and Ice Studies in Hokkaido, 38, 93, 96, Sep. 2019
Japanese, Report scientific journal - Surface velocity distribution at Pio XI glacier, Southern Patag onia Icefield
Shuntaro Hata, Shin Sug iyama, Masato Furuya, Annual Report on Snow and Ice Studies in Hokkaido, 37, 111, 114, Sep. 2018
Japanese - Fault source model for the 2016 Kumamoto earthquake sequence based on ALOS-2/PALSAR-2 pixel-offset data: evidence for dynamic slip partitioning (vol 68, 169, 2016)
Yuji Himematsu, Masato Furuya, EARTH PLANETS AND SPACE, 68, Dec. 2016
English, Others - 航空機SAR Pi-SAR2による剣岳東斜面の二つの山岳氷河の観測とその解釈
古屋正人, 福井幸太郎, 児島正一郎, 松岡建志, 日本地球惑星科学連合大会予稿集(Web), 2016, 2016 - 航空機SAR PiSAR2による剣岳の氷河観測-その2-
古屋正人, 福井幸太郎, 松岡建志, 児島正一郎, 杉山慎, 澤柿教伸, 日本測地学会講演会要旨, 124th, 2015 - Report of the 2015 IUGG general assembly
Kosuke Heki, Takeshi Iinuma, Toshimichi Otsubo, Teruyuki Kato, Youichiro Takada, Yoshiyuki Tanaka, Koichiro Doi, Takuya Nishimura, Manabu Hashimoto, Toshio Fukushima, Yoichi Fukuda, Masato Furuya, Koji Matsuo, Journal of the Geodetic Society of Japan, 61, 3, 173, 182, 01 Jan. 2015
The Geodetic Society of Japan, Japanese - 航空機SAR PiSAR2による剣岳の氷河観測
古屋正人, 福井幸太郎, 松岡建志, 児島正一郎, 杉山慎, 澤柿教伸, 日本測地学会講演会要旨, 122nd, 2014 - Surface deformations from moderate-sized earthquakes in Mongolia observed by InSAR
AMARJARGAL Sh., KATO T., FURUYA M., Earth, planets and space, 65, 7, 713, 723, 01 Jul. 2013
English - Results of Absolute Gravity Measurements in the Tokai
Tanaka Yoshiyuki, Zhang Xinlin, Fu Guangyu, Sugano Takayuki, Matsumoto Shigeo, Furuya Masato, Sun Wenke, Okubo Shuhei, Bulletin of the Earthquake Research Institute, University of Tokyo, 87, 1, 1, 6, 31 May 2013
Gravity changes observed with FG5 absolute gravimeters during the period 1996-2012 in the Tokai area are reported. There are three observation sites in the area, where gravity changes were measured once or twice a year. In Omaezaki, located at the cusp of the Peninsula, gravity increased 10 microGals over 16 years. In Kikugawa, at the center of the Peninsula, gravity increased 5 microGals from 2008 to 2012. In Toyohashi, located to the west of lake Hamana-ko, where the long-term slow slip began in 2000, gravity decreased 6 microGals from 2004 to 2012. The rates of these gravity changes do not agree completely with those inferred from crustal uplift/subsidence observed by GPS, implying the possibility that mass redistributions are occurring underground. Monitoring and modeling those mass redistributions are important to understand inter-seismic crustal activities including slow slips, and to reveal stress accumulation processes in a subduction zone., The University of Tokyo, Japanese - B2-04 Mechanism of Large Scale Mass Movement at Hanayama Caldera Driven by Strong Motion of Two Large Earthquakes in 2008 and 2011 : Search for a Hint toward the Understanding of Volcano Edifice Collapse
Murakami Makoto, Okuyama Satoshi, Furuya Masato, Abe Takahiro, Programme and abstracts the Volcanological Society of Japan, 2012, 72, 72, 14 Oct. 2012
Volcanological Society of Japan, Japanese - BI-2-9 Recent Application Examples of Synthetic Aperture Radar in Earth and Planetary Sciences
Furuya Masato, Proceedings of the Society Conference of IEICE, 2011, 1, "SS, 29"-"SS-30", 30 Aug. 2011
The Institute of Electronics, Information and Communication Engineers, Japanese - Post-seismic surface deformation following the 2008 Iwate-Miyagi Nairiku Earthquake detected by ALOS/PALSAR
TAKADA Youichiro, KOBAYASHI Tomokazu, FURUYA Masato, MURAKAMI Makoto, Journal of geodetic society of Japan, 57, 4, 181, 193, 2011
We detected post-seismic surface deformation following the 2008 Iwate-Miyagi Nairiku Earthquake (2008 June 14 JST, M6.8) by interferometric synthetic aperture radar (InSAR) analysis using ALOS/PALSAR data. The ascending interferograms indicate ∼8 cm of length increase in radar line-of-sight (LOS) to the east of Mt. Kurikoma (KRK), and decreases in it to the south of KRK and around Mt. Amadamori (AMM). The descending interferograms indicate ~4 cm of length increase in LOS to the east of Mt. Kunimiyama (KNM), and around AMM. We found that a west-dipping high-angle reverse fault roughly explains overall pattern of the length changes in LOS (ΔLOS) to the east of KNM. We demonstrated that ALOS/PALSAR has a strong ability to detect surface deformation lurking in such a vast mountainous area., The Geodetic Society of Japan, Japanese - 重力変動を用いた,比較サブダクション学―1.北海道東部
OKUBO SHUHEI, SUN W, TANAKA YOSHIYUKI, SUGANO TAKAYUKI, TAKAMORI AKITERU, OSHIMA HIROMITSU, FURUYA MASATO, MAEKAWA TOKUMITSU, MATSUMOTO SHIGEO, 日本測地学会講演会要旨, 112th, 185, 186, 2009
Japanese - Satellite Remote Sensing of Earthquakes and Volcanic Eruption : a Case Study of the 2007 Chuetsu-Oki Earthquake
FURUYA Masato, 計測と制御 = Journal of the Society of Instrument and Control Engineers, 47, 12, 981, 986, 10 Dec. 2008
計測自動制御学会, Japanese - Report on the Envisat Symposium 2007
FURUYA Masato, 測地学会誌, 53, 2, 197, 199, 25 Jun. 2007
日本測地学会, Japanese - Geodesy Text
Masato Furuya, 日本測地学会, 2004
Japanese - Report of the IAG2001 Scientific Assembly in Budapest
TAKEMOTO Shuzo, TAKAHASHI Fujinobu, KUROISHI Yuki, FURUYA Masato, HIOKI Kosuke, KIMATA Fumiaki, 測地学会誌, 48, 1, 35, 44, 25 Mar. 2002
日本測地学会, Japanese - 重力の時空間変動からよみとる三宅島火山活動の推移 (その1) 陥没孔形成前まで
FURUYA MASATO, OKUBO SHUHEI, WATANABE HIDEFUMI, OIKAWA JUN, MAEKAWA TOKUMITSU, OSHIMA HIROMITSU, MATSUMOTO KOJI, 日本地震学会秋季大会講演予稿集, 2000, 9, 09 Nov. 2000
Japanese - 重力の時空間変動からよみとる三宅島火山活動の推移 (その2) 陥没孔形成後
OKUBO SHUHEI, FURUYA MASATO, SUN W, TANAKA YOSHIYUKI, WATANABE HIDEFUMI, OIKAWA JUN, MAEKAWA TOKUMITSU, OSHIMA HIROMITSU, 日本地震学会秋季大会講演予稿集, 2000, 9, 09 Nov. 2000
Japanese
Books and other publications
Affiliated academic society
Research Themes
- Mapping permafrost thawing at fire-scars and onsite observations of their environmental changes
Grants-in-Aid for Scientific Research
01 Apr. 2023 - 31 Mar. 2028
古屋 正人, 石川 守, 岩花 剛, 柳谷 一輝
永久凍土の融解により凍土中に封じ込められていた炭素(C)が再放出することによって、さらなる温暖化を生み出す可能性がPermafrost Carbon Feedbackとして懸念されているが、その実態は不明な点が多い。地上気温が徐々に上昇することに伴う凍土融解(Gradual thaw)と山火事等による地表擾乱に伴う急で突発的な凍土融解(Abrupt thaw)がありうる中で、前者はモデル予測がしやすいのに対し、後者は文字通りどこで起きるかもわからない。本研究では人工衛星搭載の合成開口レーダー(Synthetic Aperture Radar:SAR)の観測を通じて後者の定量化を目指している。対象領域として、ロシアのサハ共和国バタガイ、米国カナダ国境にあるユーコン準州ビーバークリーク、カナダのノースウェストテリトリでの森林火災跡地での融解沈下をSAR画像を用いた干渉法(Interferometric SAR:InSAR)で検出して、時空間変動を調べた。
バタガイとビーバークリークにおいては、ALOS-2の高分解能画像(約3m)で調べることによって、現地調査との対応も詳細に調べている。Yanagiya et al (2023)で報告したバタガイの2018年火災跡では、2020年以降の3年間で最大20cmの沈降を検出した。時系列解析の結果によると、晩夏にステップ状に沈降を起こしていることが分かる。ただし、火災後内部での沈降分布は不均一が高い。
2023年8月にも前年に引き続き、ビーバークリークの2019年火災跡地で現地調査を実施した。620メートルの観測線を設定し、30メートルおきに融解深をメタルプローブで測定した。観測線の南端で気温計、地温計を設置するとともに、隣接する非火災跡地のコントロールサイトでも同様の測定を実施した。
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 23K25947 - Mapping permafrost thawing at fire-scars and onsite observations of their environmental changes
Kakenhi Kiban (B)
Apr. 2023 - Mar. 2028
Masato Furuya, Mamoru Ishikawa, Go Iwahana, Kazuki Yanagiya
JSPS, 基盤研究(B), Hokkaido University, Principal investigator, 23H01251 - ALOS4ice: Cutting-edge Polar Observation Science by Satellite SAR Imageries
特別共同研究
Apr. 2024 - Mar. 2027
National Institute of Polar Research, 国立極地研究所, Principal investigator, B24-01 - Ice front processes and evolution mechanisms of calving glaciers -comparison between lake- and ocean terminating glaciers-
Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)
Apr. 2020 - Mar. 2025
Shin Sugiyama, Hironobu Suga, Masato Furuya, Shigeru Aoki
前年度に引き続き、2021年度もCOVID-19の影響を受けて、チリおよびアルゼンチンでの氷河観測が実施できない状況となった。そこで当初の計画を一部変更して、南極における野外観測を実施すると共に、人工衛星データを使った解析に力を入れた。その結果、南極のカービング氷河における重要な観測データが得られた他、既存のデータと衛星データの解析で論文出版と学会発表の成果が挙がった。
(1) 野外観測： 2021年12月から2022年1月にかけて、南極ラングホブデ氷河で熱水掘削を含む観測を実施して、カービング氷河の底面観測に成功した。当初計画とは異なる地域、異なる手法による観測であるが、氷河氷床と海洋の相互作用解明につながる重要なデータが得られたと考えている。このほか、パタゴニアでの氷河・氷河湖・海洋調査に向けて、観測機器の調査と準備を行った。特にマルチビームソナーを使った観測に関して、専門業者への観測委託の検討が進んだ。
(2) データ解析： 過去にチリ・グレイ氷河の前縁湖で測定した水温と流速データを解析して、氷河排水が氷河湖の水温季節変動に与える影響を明らかにした。また人工衛星データの解析によって、パタゴニア西部グレーベ湖で2020年に起きた急激な水位低下を発見した。詳しい解析の結果、この現象が近年では世界最大の氷河湖排水イベントであることが判明した。
(3) 論文出版・学会発表：グレイ湖で測定した通年の水温変化をNature Communications誌に出版した他、氷河湖排水イベントをCommunications Earth & Environment誌に投稿中。COVID-19の影響で海外における学会発表は困難となり、国内での学会で成果を発表した。
(4) 研究会合：10月にオスロ大学の研究者とオンラインでワークショップを開催した他、研究チームでの小規模な会合を適宜開催した。
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), Hokkaido University, Coinvestigator, 20H00186 - Post-wildfire ground deformation over permafrost area: detection and modeling of spatial-temporal changes
Grand-in-aid for scientific research, Kiban (C)
Apr. 2019 - Mar. 2022
FURUYA Masato
MEXT, Principal investigator, Competitive research funding - Extreme Episodes in the Atmosphere viewed by InSAR
Grants-in-Aid for Scientific Research
Apr. 2018 - Mar. 2020
FURUYA Masato
【課題A】集中豪雨/雷雲へのInSAR Split-Spectrum-Method(SSM)の適用と位相モデルの検討
今年度はALOS2によるInSARで5つの豪雨事例に伴う水蒸気分布を捉えた：鹿児島県(2018年7月3日)、高知県(2018年8月15日)、兵庫県(2018年6月29日)、大阪府(2018年5月13日)、近畿地方での台風21号Jebi(2018年9月4日)．鹿児島県、高知県のデータからは降雨レーダーの降水分布に対応した顕著な水蒸気分布の異常が見出された．Split-Spectrum-Method(SSM)を適用した結果もほぼ非分散性位相に起因しているが，前年度に報告した事例と同様，分散性成分の方にも豪雨発生域に異常位相が有意に残っており、降水粒子を検出している可能性がある．
【課題B】電離層擾乱へのInSAR SSM の適用
ALOS2のScanSARモード画像を用いて広域の電離層擾乱の検出を試みた．スポラディックE（Es）は日本域では夏の昼間の発生頻度が高く，ALOS2 ScanSARの撮像時刻がマッチせずInSARで検出できるには至らなかったが，伝搬性の電離層擾乱は明確に捉えられた．
ALOS1データを用いて、新たに広島/岡山付近のEsイベント(2010年6月26日)を検出した．SSMを用いた電離層起源の分散性位相とそれ以外の非分散性位相に概ね分離できるが，分離前には異常が見られない箇所で分散性/非分散性位相のそれぞれに新たに異常が現れ、しかも分散性/非分散性位相で打ち消し合う結果が見られた．Es発生時以外では同様のシグナルが見られないこと、これまでのEs検出例でも同様の事例があることから，Es時に特有の「現象」である可能性がある．
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area), Hokkaido University, Principal investigator, Competitive research funding, 18H04435 - 東シベリア平原の森林火災に伴う地盤変動の時空間変化の検出とモデリング
共同推進研究
Apr. 2018 - Mar. 2019
古屋 正人
北極域研究共同研究拠点研究者コミュニティー推進事業, Principal investigator, Competitive research funding - 電離層補正を考慮したInSARによる永久凍土域の地盤変動検出
共同推進研究
Apr. 2017 - Mar. 2018
古屋 正人
北極域研究共同研究拠点研究者コミュニティー推進事業, Principal investigator, Competitive research funding - InSARによる永久凍土地域の地盤変動モニターに向けた電離層補正手法の確立
共同推進研究
Apr. 2016 - Mar. 2017
古屋 正人
北極域研究共同研究拠点研究者コミュニティー推進事業, Principal investigator, Competitive research funding - The role of glacier dynamics on rapid retreat of calving glaciers
Grants-in-Aid for Scientific Research
01 Apr. 2011 - 31 Mar. 2015
SUGIYAMA SHIN, SAWAGAKI Takanobu, NAITO Nozomu, FURUYA Masato, ENOMOTO Hiroyuki
We carried out satellite and field measurements to study the role of glacier dynamics in rapid retreat of calving glaciers. Glacier front positions and ice speed over the entire area of Southern Patagonia Icefield were quantified from 1984 to 2011. Details of the data revealed the fundamental role of glacier dynamics in the significantly large retreat observed in several glaciers. Lake measurements confirmed the influence of bed geometry on glacier stability, and unique lake temperature structures in front of calving glaciers. We also performed hot water drilling on glaciers on Livingston Island in Antarctic Peninsula. Subglacial and englacial measurements provided us clues to understand the mechanism of short-term ice speed variations. These results demonstrated that the glacier dynamics is a key driver of the recent rapid retreat of calving glaciers, and also suggested potentially important role of ice-lake interactions in the glacier change.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 23403006 - Detecting spatial-temporal changes of glacier surge by satellite remote sensing
Grants-in-Aid for Scientific Research
Apr. 2012 - Mar. 2015
FURUYA Masato
Glacier surge exhibits order(s)-of-magnitude faster surface velocities during the short active phase, accompanying terminus advances and ice-thickness changes. However, the generation mechanisms remain uncertain because of the limited observations of surging glaciers that repeat the active phase after the decades-long quiescent phase. Here we use satellite synthetic aperture radar (SAR) images to examine the spatial-temporal changes in surface velocities, aiming to understand the mechanisms. We first identified surging glaciers at the West Kunlun Shan, NW Tibet. During the more-than-5-years-long active phase, we could detect clear seasonal modulations in their speeds that accelerated from fall to winter. In addition, we have discovered winter speed-up signals at the quiescent surge-type glaciers in Yukon, Canada. Namely, surge-type glaciers can accelerate even in the absence of surface meltwater input, suggesting the presence of englacial water and its rerouting toward the base.
Japan Society for the Promotion of Science, Grant-in-Aid for Challenging Exploratory Research, Hokkaido University, Principal investigator, Competitive research funding, 24651001 - Imaging magma plumbing system using InSAR analyses with corner reflectors
Grants-in-Aid for Scientific Research
2009 - 2011
OIKAWA Jun, FURUYA Masato, IGUCHI Masato, AOKI Yosuke, WATADA Shingo
Suwanose-jima is one of the most active volcano of Japan with quasi-continuous unrest since 1957. It is monitored with broadband seismometers and tiltmeters but the difficulty in ground access to the island prohibits us to construct large-enough network to understand the magma plumbing system solely from the ground-based monitoring network. Ground deformation observed by the InSAR analysis thus has a potential to gain moreinsights into our understanding of the magma plumbing system of this volcano.We analyzed 43 images (19 ascending and 24 descending images, respectively) taken between March, 2007, and February, 2011. Despite strong explosive eruption activity in2007-2011, no deformation was detected for interferograms from all possible pairs except for small (several centimeters of line-of-sight changes) deformaiton in an interferogram between August 17, 2007, and January 2, 2008, which could represent deformation due to explosive eruptions in December, 2007. Explosive eruptions without significant deformation can be interpreted as eruptions without feeding magma from depth or magma propagation through the conduit without deformation.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), The University of Tokyo, 21540432 - Interdisciplinary earth science from time-variable gravity
Grants-in-Aid for Scientific Research
2008 - 2010
HEKI Kosuke, FURUYA Masato
Coseismic gravity changes associated with the 2010 Chile Earthquake have been detected with GRACE satellites (Heki & Matsuo, 2010 GRL). We also detected ice loss amounting up to 40 Gt/yr in the Asian High Mountains including the Himalayan glaciers (Matsuo & Heki, 2010 EPSL). We also revealed that quadratic signals in time-variable gravity are due mainly to linear changes in precipitation (Ogawa et al., 2011 GJI).
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, 20540402 - Deciphering deformation styles of inland plate boundaries by InSAR
Grants-in-Aid for Scientific Research(基盤研究(B))
2007 - 2009
Masato FURUYA, Youichiro TAKADA
Using SAR data, we detected crustal deformation signals associated with several inland earthquakes in and around continental plate boundaries. All the data revealed unexpected signals that could not be predicted from the prompt seismological estimates of the fault sources, and thus would be overlooked if SAR were not used. We discovered a long-lasting afterslip due to the M5 earthquake at the Chaman fault, Afghanistan. All the events, including the 1996 Onikobe, 2007 Chuetsu-oki, 2008 Iwate-Miyagi, 2008 Yutian, 2008 Wenchuan, revealed complex crustal displacements that could not be explaine...
Ministry of Education, Culture, Sports, Science and Technology, 基盤研究(B), 東京大学->北海道大学, Principal investigator, Competitive research funding, 19340123 - Comprehensive study of the damage caused by the 2008 Great Sichuan Earthquake
Grants-in-Aid for Scientific Research
2008 - 2008
KONAGAI Kazuo, CHIGIRA Masahiro, SHIOHARA Hitoshi, HIRATA Naoshi, MORI James J., KUWAHARA Yasuto, FURUYA Masato, SUN Wenke, IKEDA Yasutaka, ATSUMI Tomohide, KAMAI Toshitaka, FUKUOKA Hiroshi, WANG Fawu, TAKAHASHI Yoshikazu, OHMACHI Tatsuo, KAWASHIMA Kazuhiko, KONO Susumu, KABEYASAWA Toshimi, NAKANO Yoshiaki, MIYAZAWA Masatoshi, TOBITA Mikio, SHIMADA Masanobu, KANO Kenichi, LIN Weiren, TATANO Hirokazu, YAMORI Katsuya, KAJITANI Yoshio
2008年5月12日に中国四川省汶川県付近を震源とするマグニチュード(M)7.9(米国地質調査所)の内陸巨大地震が発生し、死者7万人、行方不明者2万人に達すると推定される甚大な被害がもたらされた。この地震を引き起こした断層の長さは280km程度と推定され、内陸部で発生した地震としては最大級の地震である。我が国の内陸部でも、これまでに、M8級の巨大地震として1891年濃尾地震が発生し、7200名余の死者を出し、今後もM8級の地震が発生する可能性が指摘されている(糸魚川―静岡構造線断層帯、富士川河口断層帯や中央構造線断層帯など)。しかし、近年発生した最大規模の被害地震は平成7年兵庫県南部地震(阪神・淡路大震災)で、M7.3、断層の長さ50km程度であり、M8級の巨大地震の発生機構は十分に明らかにされていない。また今回の地震では断層沿いの山地に大量の不安定な土石が残されていて、下流域にとって土石流などの深刻な不安材料となっている。強烈な揺れへの対応とあわせ、長期に及ぶ復興の課題に資する科学的調査もまた重要である。このような理学・工学そして社会対応に至るまであらゆる局面から本地震の実態と、その影響を科学的に検証していくことは、我が国の内陸における巨大地震の発生機構の解明に資するのみならず、地震災害の軽減、そして合理的な復興戦略策定に資するデータを提供することに繋がり、我が国の防災戦略に役立つ。このような観点で中国地震局を正式なカウンターパートとしての共同調査を行った。主要な調査対象は(1) 斜面災害、(2) 社会基盤施設被害、(3) 建築・家屋被害、(4)地震学的分野、(5) 地殻変動、(6) 活断層、(7) 救援・復旧支援活動及び経済的影響、の7領域に及ぶ。これらの調査の中で、「だいち」(JAXA)「だいち」の緊急観測やALOS衛星画像の解析などで中国側に重要な情報を提供できた。このなかにはInSAR画像の解析や、5万㎡以上の面積の斜面崩壊分布を明らかにしたことなどが挙げられる. また, 現地調査でも衛星で確認された崩壊地で白雲岩などの炭酸塩岩に最も多くの崩壊が発生していることや、崩壊の方向に指向性があることなどを見出した. さらに社会基盤施設や建築物・家屋の崩壊について個別の調査を行い、それぞれを詳細なレポートとしてまとめている。一方で、現地は物理的にも立ち入り困難な場所があり、その被害の全貌を把握することは単年度の本研究の枠を超えて進めるべき課題で、今後の相互の学術発展のみならず有効な復旧戦略構築のためにも日中の協力の枠組みを強化することがいよいよ重要である。
Japan Society for the Promotion of Science, The University of Tokyo, 20900002 - 多重干渉SAR画像による経年性地殻変動の検出
科学研究費補助金(若手研究(B))
2002 - 2003
古屋 正人
今年度は(1)1996年8月に宮城秋田山形県境付近で発生した「鬼首地震」による地震時地殻変動、(2)伊豆大島火山のカルデラ域における経年的沈降の「微細構造」の検出に成功した。以下にそれぞれの概略を述べる。(1)1996年8月11日に宮城秋田山形県境付近の鬼首地域でM5.9の地震が発生した。地震そのものの規模は大きくないが震源深さが10kmよりも浅かったために,現存するGPS等の宇宙技術によって検出可能な地表変位が現れた。しかしM5.9の中規模の地震による地表変位は水平距離で10km程度にしか及ばず,山間部での地震であったためGPS受信機の空間分布は疎らなため断層モデルを推定できるほどの空間分解能では検出できていなかった。今回JERS1(ふよう1号)のデータを用いて干渉SAR解析を行い,独立な3ペアにつき地震時地殻変動を検出できた。その結果は余震分布で推定された断層モデルで概ね説明できるが,空間的な広がりの点で地震学的には説明できない変位が得られている。(2)伊豆大島カルデラにあっては,JERS1データの干渉SARによって経年的な沈降が報告されている。この事実に基づき「多重干渉SARによる経年性地殻変動検出」のテストフィールドとして伊豆大島カルデラを選び、ERS1/2による干渉SAR解析を行った。ERS1/2のデータを用いたことによって、沈降の微細構造が判明した。沈降域と過去の...
文部科学省, 若手研究(B), 東京大学, Principal investigator, Competitive research funding, 14740264 - Crustal deformations caused by seismic and volcanic sources in a spherical earth
Grants-in-Aid for Scientific Research
2001 - 2003
WENKE Sun, FURUTA Masato, OKUBO Shuhei
Mainly theoretical research was performed : 1.The effects of the Earth's curvature and radial heterogeneity in dislocation studies were studied, though comparing the coseismic deformations caused by dislocations in half space and homogeneous spherical earth models, a homogeneous sphere and a layer spherical model. It was learnt that both the effects are large. 2.To overcome the disadvantages of the current dislocation theories, a new theory for calculating asymptotic deformations excited by a point dislocation in a spherical symmetric earth model was presented. This theory is given by a closed form of mathematical expressions, so that it is mathematically simple and can be applied easily. Moreover, since the asymptotic theory includes sphericity and vertical structure effects, it is physically more reasonable than the flat-earth theory. 3.The crustal deformation caused by the 2000 Miyakejima volcanic and seismic activities was studied. 4.The co-seismic deformation in spectrum was also considered, so that the ability of satellite gravity missions to detect co-seismic geoid and gravity changes were observed and determined. 6.The expressions of co-seismic strains were derived. The results were presented in different national/international conferences, and published in 8 papers.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), The University of Tokyo, 13640420 - Do the gravity and geoid height changes accumulate during the course of earthquake cycle?
Grants-in-Aid for Scientific Research
2001 - 2003
OKUBO Shuhei, SUN Wenke, FURUYA Masato, HIBIYA Toshiyuki
We formulated the gravity, geoid height and elevation changes due to fault motoin in a Maxwell viscoelastic earth. The formulation is implemented to a FORTRAN computer code, which enables us to compute interseismic gravity/elevation changes during an earthquake cycle based on the Savage's backslip model. We applied the technique to the interseismic deformation around the Tokai area where the Philippine Sea plate is subducting beneath the Eurasian plate.
The model successfully reproduces the steady subsidence when we assume reasonable viscosity profile and asperity distribution. On the contrary, we find the computed gravity change rate is significantly larger than the observed one. The result casts profound doubt on the validity of the Savage's supposition that no deformation accumulates over repeated seismic cycles.
We applied the formulation to the analysis of gravity change before and after the Tokachi-oki Earthquake (M8.1, September 26, 2003). To be more specific, we calculated the interseismic gravity change rate to reduce the absolute gravity value taken several years before the earthquake to the one just before the earthquake. When compared with the absolute gravity value just after the earthquake, it enables us to estimate the coseismic gravity change. The change agrees well with the theoretically predicted one.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), The University of Tokyo, 13440130 - Study of great earthquakes by means of satellite altimetry and Synthetic aperture radar.
Grants-in-Aid for Scientific Research
1998 - 2000
OKUBO Shuhei, FURUYA Masato, HIBIYA Toshiyuki
1. We carried out a research to eliminate the meteorological disturbance on the differential interferometry of SAR data by using a JMA regional numerical model. The technique enables us to detect long wavelength undulated fringes at western coast of Korean Peninsula by ERS-1 satellite radar interferometry. Though the amplitude in the derived interferogram is larger than that of prediction, the spatial pattern is similar to the theoretical computation of inland flexural response to the ocean tide in the Yellow Sea.
2. We developed a recipe to compute gravity/geoid height change and vertical displacement caused by a point dislocation in a spherical, viscoelastic and self-gravitating earth. It enables us to trace the crustal deformation excited by a great earthquake. Time evolutions for a point source located in the elastic lithosphere is distinctively different from that when a source is in the viscoelastic asthenosphere.
3. As a first step toward a numerical modeling of global internal tide field, the distribution of the M2 internal tide in the North Pacific is examined using a three-dimensional primitive equation numerical model. The numerical simulation shows that energetic internal tides are generated over the prominent bottom topographies in the Indonesian Archipelago, the Solomon Archipelago, the Aleutian Archipelago as well as over the continental shelf slope in the East China Sea, the Izu-Ogasawara Ridge and the Hawaiian Ridge. In particular, the calculated spatial distribution of the M2 internal tide around the Hawaiian Ridge agrees very well with that obtained from the Topex/Poseidon altimetry.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B)., University of Tokyo, 10440126 - 主として測地学による地球惑星ダイナミクスの観測的理論的研究
1997
Competitive research funding
