Research activity information

• Oct. 2024, The Geodetic Society of Japan, Tsuboi Prize (Group)
  国内のSAR利用研究拡大への貢献
  PIXEL(PALSAR Interferometry Consortium to;Study our Evolving;surface) 古屋正人;青木陽介;小澤拓;田中明子;福島洋;安藤忍;高田陽一郎;奥山哲;木下陽平
• May 2021, 日本火山学会, The Volcanological Society of Japan Award (Paper)
  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, Shohei Narita, Taku Ozawa, Yosuke Aoki, Masanobu Shimada, Masato Furuya, Youichiro Takada, Makoto Murakami (2020) Precursory ground deformation of the 2018 phreatic eruption on Iwo-Yama volcano, revealed by four-dimensional joint analysis of airborne and spaceborne InSAR. Earth Planet Space, 72, 1, doi:10.1186/ s40623-020-01280-5., Japan society
• Oct. 2018, 日本測地学会, 日本測地学会坪井賞（個人賞）
  InSARとGNSSによる東北地方太平洋沖地震前と後の内陸地殻変動様式の解明
  高田 陽一郎, Japan society
• 2012, 日本活断層学会, 日本活断層学会論文賞
  2008年岩手・宮城内陸地震に伴い岩手県奥州市国見山南麓に出現した地震断層北端部の性状
  丸山 正;遠田 晋次;吉見 雅行;安藤 亮輔;高田 陽一郎;斎藤 英二;林 舟;小俣 雅志, Japan society

• High-resolution strain rate mapping around inland plate boundary within a volcanic arc using L-band InSAR and dense GNSS networks
  Shogo Nagaoka; Youichiro Takada; Takuya Nishimura; Takeshi Sagiya; Yusaku Ohta
  Scientific Reports, Springer Science and Business Media LLC, 07 May 2026, [Peer-reviewed]
  English, Scientific journal, Abstract
  
  Crustal deformation in central Japan occurs in a highly complex manner characterized by the Itoigawa–Shizuoka Tectonic Line (ISTL), the geologic boundary between the North American and the Eurasian plates. In addition, a prominent strain concentration zone, known as the Niigata–Kobe tectonic zone (NKTZ), has been identified by GNSS surveys. The existence of a volcanic chain introduces another complexity through its rheological heterogeneity. In this region, the spatial resolution and accuracy of strain rate mapping by conventional ground-based geodetic surveys have been limited by dense vegetation and rugged topography. Here, we integrate L-band InSAR data (2014–2023), which can resolve deformation in densely vegetated mountainous areas where ground-based measurements alone are spatially sparse, with GNSS data from a dense network (average spacing of $$\sim 10~\textrm{km}$$ ) including private-sector stations, to generate a high-resolution interseismic strain rate map. We identify sharply localized strain rates along the northern ISTL ( $$\sim 5\times 10^{-7}~\mathrm {yr^{-1 } }$$ ) and parts of the NKTZ ( $$\sim 4\times 10^{-7}~\mathrm {yr^{-1 } }$$ ), which are of larger magnitude and more spatially confined than GNSS-only estimates. We also find a distinct strain rate concentration ( $$\sim 3\times 10^{-7}~\mathrm {yr^{-1 } }$$ ) along the southern extension of the Hida Mountains volcanic zone. Some of these concentrated strain rate zones align with known active faults, while others do not (e.g., the southern extension of the Hida range). This study presents the first L-band InSAR-based strain rate map in a densely vegetated mountainous region, revealing the complex deformation style in volcanic arcs and providing new insights into strain accumulation processes., 49499174
• Slope-Correlated Bias in Mean Velocity Field Derived From L-Band InSAR Time-Series
  Shogo Nagaoka; Youichiro Takada
  IEEE Xplore, 9th Asia-Pacific Conference on Synthetic Aperture Radar (APSAR), 1, 4, IEEE, 05 Oct. 2025, [Peer-reviewed]
  English, International conference proceedings
• Strong Fault Interaction in Double‐Vergence Structure: Lessons From the 2022 Yuli Earthquake and the 2022 Chihshang Earthquake, Eastern Taiwan
  Yuri Ishimaru; Youichiro Takada; Kuo‐En Ching; Wu‐Lung Chang
  Journal of Geophysical Research: Solid Earth, 130, 7, American Geophysical Union (AGU), 10 Jul. 2025, [Peer-reviewed]
  English, Scientific journal, Abstract
  
  The Longitudinal Valley Fault (LVF) and the Central Range Fault (CRF) in eastern Taiwan consist of a head‐to‐head double‐vergence structure hosting disastrous earthquakes. It was previously proposed that the fault slip on one of these faults suppresses the earthquake generation on the other. Nonetheless, the 2022 Chihshang earthquake (M_w 7.0) on the CRF occurred soon after the 2022 Yuli earthquake (M_w 6.7) on the LVF. Here, we provide a comprehensive framework of the fault interaction consistently explaining these contradictory findings. First, we estimated the coseismic slip distribution of the Yuli earthquake from Global Navigation Satellite System (GNSS) and L‐band satellite interferograms. The results indicate almost pure reverse faulting. Second, with the estimated slip distribution, we calculated changes in Coulomb failure function (ΔCFF) on the CRF due to the Yuli earthquake on the LVF. The ΔCFF reaches +0.25 MPa around the main rupture area of the Chihshang earthquake, which is equivalent to the clock advance of 36–100 years, suggesting a large impact on the earthquake generation cycles. Finally, we found that a rake angle of fault slip has a significant effect on the ΔCFF on the other fault in the double‐vergence structure: it takes large positive values when 90° like the Yuli earthquake, but almost negative when 45° or less, which comprehensively explains the seismic quiescence previously reported and the positive ΔCFF on the CRF caused by the Yuli earthquake. The strong impact of the rake angle is also supported by the temporal distribution of historical earthquakes in eastern Taiwan.
• Improved application of the split-spectrum method to L-band interferograms for ionospheric phase mitigation: a practical recipe.
  Shogo Nagaoka; Youichiro Takada; Yu Morishita
  Earth Planets and Space, 77, 82, 1, 21, Jun. 2025, [Peer-reviewed]
  English, Scientific journal
• Inferring 3-D rheology of low-viscosity zone around Quaternary volcanoes of NE Japan from postseismic deformation of the 2011 Tohoku-Oki earthquake
  Sambuddha Dhar; Youichiro Takada; Jun Muto
  Journal of Geophysical Research -Solid Earth-, 130, e2024JB029939, Mar. 2025, [Peer-reviewed]
  English, Scientific journal, 36880396
• 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, 145, 1, 16, Springer Science and Business Media LLC, Dec. 2020, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Spatiotemporal behavior of a large-scale landslide at Mt. Onnebetsu-dake, Japan, detected by three L-band SAR satellites
  Youichiro Takada; George Motono
  Earth, Planets and Space, 72, 1, 1, 18, Springer Science and Business Media LLC, Sep. 2020, [Peer-reviewed], [Lead author, Corresponding author], [International Magazine]
  English, Scientific journal,
  We applied differential InSAR analysis to the Shiretoko Peninsula, northeastern Hokkaido, Japan. All the interferograms of long temporal baseline (~ 3 years) processed from SAR data of three L-band satellites (JERS-1, ALOS, ALOS-2) commonly indicate remarkable phase changes due to the landslide movement at the southeastern flank of Mt. Onnebetsu-dake, a Quaternary stratovolcano. The area of interferometric phase change matches to known landslide morphologies. Judging from the timing of the SAR image acquisitions, this landslide has been moving at least from 1993 to the present. Successive interferograms of 1-year temporal baseline indicate the temporal fluctuation of the landslide velocity. Especially for the descending interferograms, the positive line-of-sight (LOS) length change, which indicates large subsidence relative to the horizontal movement, is observed in the upslope section of the landslide during 1993–1998, while the negative LOS change is observed in the middle and the downslope section after 2007 indicating less subsidence. The landslide activity culminates from 2014 to 2017: the eastward and the vertical displacement rates reach ~ 6 and ~ 2 cm/yr, respectively. Utilizing high spatial resolution of ALOS and ALOS-2 data, we investigated velocity distribution inside the landslide. During 2007–2010, the eastward component of surface displacement increases toward the east, implying that the landslide extends toward the east. During 2014–2017, the vertical displacement profile exhibits spatially periodic uplift and subsidence consistent with surface gradient, which indicates the ongoing deformation driven by gravitational force. Heavy rainfall associated with three typhoons in August 2016 might have brought about an increase in the landslide velocity, possibly due to elevated pore-fluid pressure within and/or at the base of the landslide material. Also, annual rainfall would be an important factor that prescribes the landslide velocity averaged over 3 years.
• Introduction to the Special Issue “Crustal Dynamics (Part II): Toward the Integration of Geology and Geophysics”
  Yukitoshi FUKAHATA; Youichiro TAKADA; Kiyokazu OOHASHI; Akiko TANAKA
  Journal of Geography (Chigaku Zasshi), 129, 4, 447, 450, Tokyo Geographical Society, 25 Aug. 2020
  Scientific journal
• Overview of the Special Issue “Crustal Dynamics (Part II): Toward the Integration of Geology and Geophysics”
  Yukitoshi FUKAHATA; Youichiro TAKADA; Kiyokazu OOHASHI; Akiko TANAKA
  Journal of Geography (Chigaku Zasshi), 129, 4, 443, 445, Tokyo Geographical Society, 25 Aug. 2020
  Scientific journal
• Introduction to the Special Issue “Crustal Dynamics (Part I): From a Macroscopic View”
  Yukitoshi FUKAHATA; Kiyokazu OOHASHI; Youichiro TAKADA; Akiko TANAKA
  Journal of Geography (Chigaku Zasshi), 128, 5, 685, 687, Tokyo Geographical Society, 25 Oct. 2019
  Scientific journal
• Overview of the Special Issue "Crustal Dynamics (Part I) : From a Macroscopic View"
  Fukahata Yukitoshi; Oohashi Kiyokazu; Takada Youichiro; Tanaka Akiko
  JOURNAL OF GEOGRAPHY-CHIGAKU ZASSHI, 128, 5, 681, 683, Oct. 2019
  English, Scientific journal
• InSARとGNSSによる東北地方太平洋沖地震前と後の内陸地殻変動様式の解明
  高田 陽一郎
  測地学会誌, 65, 1, 13, 2019, [Peer-reviewed], [Lead author, Corresponding author], [Domestic magazines]
  Japanese, Scientific journal
• Aseismic fold growth in southwestern Taiwan detected by InSAR and GNSS
  Kotaro Tsukahara; Youichiro Takada
  Earth, Planets and Space, 70, 1, 01 Dec. 2018, [Peer-reviewed], [Last author], [International Magazine]
  English, Scientific journal
• Interseismic crustal deformation in and around the Atotsugawa fault system, central Japan, detected by InSAR and GNSS
  Youichiro Takada; Takeshi Sagiya; Takuya Nishimura
  Earth, Planets and Space, 70, 1, Springer Berlin Heidelberg, 01 Dec. 2018, [Peer-reviewed], [Lead author, Corresponding author], [International Magazine]
  English, Scientific journal
• Which is heterogeneous, stress or strength? An estimation from high-density seismic observations Crustal Dynamics: Unified Understanding of Geodynamics Processes at Different Time and Length Scales Yoshihisa Iio, Richard H. Sibson, Toru Takeshita, Takeshi
  Yoshihisa Iio; Itaru Yoneda; Masayo Sawada; Tsutomu Miura; Hiroshi Katao; Yoichiro Takada; Kentaro Omura; Shigeki Horiuchi
  Earth, Planets and Space, 69, Dec. 2017, [Peer-reviewed]
• Which is heterogeneous, stress or strength? An estimation from high-density seismic observations
  Yoshihisa Iio; Itaru Yoneda; Masayo Sawada; Tsutomu Miura; Hiroshi Katao; Yoichiro Takada; Kentaro Omura; Shigeki Horiuchi
  EARTH PLANETS AND SPACE, 69, 1, Oct. 2017, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• San-in shear zone in southwest Japan, revealed by GNSS observations
  Takuya Nishimura; Youichiro Takada
  EARTH PLANETS AND SPACE, 69, 1, 85, Jun. 2017, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Stress accumulation process in and around the Atotsugawa fault, central Japan, estimated from focal mechanism analysis
  Youichiro Takada; Kei Katsumata; Hiroshi Katao; Masahiro Kosuga; Yoshihisa Iio; Takeshi Sagiya
  TECTONOPHYSICS, 682, 134, 146, Jul. 2016, [Peer-reviewed], [Lead author, Corresponding author], [International Magazine]
  English, Scientific journal
• Volcanic subsidence triggered by megathrust earthquakes
  Youichiro Takada; Yo Fukushima
  Journal of Disaster Research, 9, 3, 373, 380, Fuji Technology Press, 2014, [Peer-reviewed], [Lead author, Corresponding author], [International Magazine]
  English, Scientific journal
• Volcanic subsidence triggered by the 2011 Tohoku earthquake in Japan
  Youichiro Takada; Yo Fukushima
  NATURE GEOSCIENCE, 6, 8, 637, 641, Aug. 2013, [Peer-reviewed], [Lead author, Corresponding author], [International Magazine]
  English, Scientific journal
• Complex Ruptures of the 11 April 2011 M-w 6.6 Iwaki Earthquake Triggered by the 11 March 2011 M-w 9.0 Tohoku Earthquake, Japan
  Yo Fukushima; Youichiro Takada; Manabu Hashimoto
  BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA, 103, 2B, 1572, 1583, May 2013, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Nonplanar Fault Source Modeling of the 2008 M-w 6.9 Iwate-Miyagi Inland Earthquake in Northeast Japan
  Takahiro Abe; Masato Furuya; Youichiro Takada
  BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA, 103, 1, 507, 518, Feb. 2013, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Land Subsidence in Semarang, Indonesia, Observed by InSAR Time-Series Analysis Using ALOS/PALSAR Data
  ARIMOTO Mika; FUKUSHIMA Yo; HASHIMOTO Manbu; TAKADA Youichiro
  Journal of the Geodetic Society of Japan, 59, 2, 45, 56, The Geodetic Society of Japan, 2013, [Peer-reviewed], [Domestic magazines]
  Japanese, In order to precisely measure the land subsidence in Semarang, Indonesia, we performed a smallbaseline interferometric synthetic aperture radar (SAR) time-series analysis using the images acquired by the Japanese Advanced Land Observing Satellite (ALOS). We used a total of 34 SAR images, acquired from both the ascending and descending orbits, and obtained the subsidence timeseries in the two line-of-sight (LOS) directions. Before solving for the displacement time-series, we corrected for artifacts due to orbital inaccuracies and atmospheric phase delay. We obtained the time-series of quasi-vertical displacements by decomposing the displacement time-series in the two LOS directions. The result shows that the subsidence is limited on low-land areas where an aquifer system is well developed, suggesting that the cause of the subsidence is extraction of water from the aquifer. The subsidence rate was estimated to be practically constant with time with no clear seasonal effects. The maximum subsidence rate of 10±0.4 cm/year was obtained at a location where subsidence had not been identified before. Our study also shows the effectiveness of L-band SAR data to monitor land subsidence over time.
• Surface movements during the 2011 great Tohoku-Oki earthquake detected by ALOS/PALSAR
  HASHIMOTO, M; Y. Fukushima; Y. Takada
  Technical Report of IEICE, SANE2012, 79, 129, 134, Sep. 2012, [Invited]
  English, Scientific journal
• 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
• Characteristics of the northernmost part of the surface rupture associated with the 2008 Iwate-Miyagi Nairiku, Japan, earthquake
  Maruyama Tadashi; Toda Shinji; Yoshimi Masayuki; Ando Ryosuke; Takada Youichiro; Saito Eiji; Lin Zhou; Omata Masashi
  AFR, 2011, 34, 1, 12, Japanese Society for Active Fault Studies, 31 Mar. 2011, [Peer-reviewed], [Domestic magazines]
  Japanese, Post-earthquake airborne LiDAR DEM and field investigation reveal the details of the northernmost trace of previously reported surface rupture zone associated with the 2008 Iwate-Miyagi Nairiku earthquake, which displaced the southern slopes of the densely forested Mt. Kunimi, Oshu City, Iwate Prefecture. The LiDAR DEM allows us to unveil the distribution and slip sense of the fresh ruptures that occurred on the mountainous area. Field observation and in-situ digital surveying show that the rupture is characterized by i) curvilinear traces composed of the N-S-trending east-facing scarp with no lateral offset to the south and the NW-SE-trending northeast-facing scarp with sinistral offset to the north, ii) the uphill-facing flexure scarps that move up the southwestward-sloping mountain block toward the upslope direction with ＜1.0 m vertical offsets, iii) shortening deformation manifested by intrusion of trees on downthrown side into the upthrown side, and iv) continuous trace extending over 2 km in length. These features suggest that the rupture is a west dipping reverse fault accommodating W-E to WNW-ESE trending compression, which is consistent with several proposed source fault models inferred from seismological and geodetical studies. The location of the surface rupture corresponds to the zone of abrupt change in displacement gradient illuminated by SAR analyses. Furthermore, the large slippage at the northernmost part of the 2008 rupture zone well corresponds to the location of one of large slip patches on the causative fault as derived from waveform inversion. Together with the detail topographic measurements and trench excavations, we identified evidence for the past faulting behavior suggestive of the same slip sense along the rupture zone. We thus conclude that this portion of the surface rupture is tectonic origin reflecting the westdipping seismogenic reverse faulting.
• 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], [Lead author, Corresponding author], [Domestic magazines]
  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.
• A3-10 Crustal deformation of the volcanoes in the northeastern Japan arc induced by the 2011 Tohoku Earthquake
  Fukushima Yo; Takada Youichiro
  PROGRAMME AND ABSTRACTS THE VOLCANOLOGICAL SOCIETY OF JAPAN, 2011, 53, 53, The Volcanological Society of Japan, 2011
  Japanese
• Fault Source Modeling of the 2008 Wenchuan Earthquake Based on ALOS/PALSAR Data
  M. Furuya; T. Kobayashi; Y. Takada; M. Murakami
  BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA, 100, 5B, 2750, 2766, Nov. 2010, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Aseismic slip during the 1996 earthquake swarm in and around the Onikobe geothermal area, NE Japan
  Youichiro Takada; Masato Furuya
  EARTH AND PLANETARY SCIENCE LETTERS, 290, 3-4, 302, 310, Feb. 2010, [Peer-reviewed], [Lead author, Corresponding author], [International Magazine]
  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], [International Magazine]
  English, International conference proceedings
• 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, 7, Apr. 2009, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Coseismic displacement due to the 2008 Iwate-Miyagi Nairiku earthquake detected by ALOS/PALSAR: preliminary results
  Youichiro Takada; Tomokazu Kobayashi; Masato Furuya; Makoto Murakami
  EARTH PLANETS AND SPACE, 61, 4, E9, E12, 2009, [Peer-reviewed], [Lead author, Corresponding author], [International Magazine]
  English, Scientific journal
• General expressions for internal deformation due to a moment tensor in an elastic/viscoelastic multilayered half-space
  Akinori Hashima; Youichiro Takada; Yukitoshi Fukahata; Mitsuhiro Matsu'ura
  GEOPHYSICAL JOURNAL INTERNATIONAL, 175, 3, 992, 1012, Dec. 2008, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Development of three-dimensional basement structure in Taiwan deduced from past plate motion: Consistency with the present seismicity
  Youichiro Takada; Yukitoshi Fukahata; Akinori Hashima; Toshiko Terakawa; Kenji Fukui; Takatoshi Yanagisawa; Yasutaka Ikeda; Gaku Kimura; Mitsuhiro Matsu'ura
  TECTONICS, 26, 3, 3004, May 2007, [Peer-reviewed], [Lead author, Corresponding author], [International Magazine]
  English, Scientific journal
• Geometric evolution of a plate interface-branch fault system: Its effects on the tectonic development of the Himalayas
  Youichiro Takada; Mitsuhiro Matsu'ura
  JOURNAL OF ASIAN EARTH SCIENCES, 29, 2-3, 490, 503, Feb. 2007, [Peer-reviewed], [Lead author, Corresponding author], [International Magazine]
  English, Scientific journal
• A unified interpretation of vertical movement in Himalaya and horizontal deformation in Tibet on the basis of elastic and viscoelastic dislocation theory
  Y Takada; M Matsu'ura
  TECTONOPHYSICS, 383, 3-4, 105, 131, May 2004, [Peer-reviewed], [Lead author, Corresponding author], [International Magazine]
  English, Scientific journal
• Geometric evolution of a plate interface-branch fault system: Its effect on tectonics in Himalaya
  Takada Youichiro; Matsu'ura Mitsuhiro
  Himalayan Journal of Sciences Vol.2, pp.258-258, 2004, [Lead author, Corresponding author], [International Magazine]
  English
• 高ヒマラヤ下ランプ構造の時間発展とヒマラヤの隆起プロセス
  高田陽一郎; 松浦充宏
  月刊地球, Vol.24, No.4, pp.285-290, 24, 4, 285, 290, 海洋出版, Apr. 2002, [Lead author, Corresponding author], [Domestic magazines]
  Japanese

• 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]
  Japanese, Introduction scientific journal
• Correction to: Which is heterogeneous, stress or strength? An estimation from high-density seismic observations (Earth, Planets and Space, (2017), 69, 1, (144), 10.1186/s40623-017-0730-3)
  Yoshihisa Iio; Itaru Yoneda; Masayo Sawada; Tsutomu Miura; Hiroshi Katao; Yoichiro Takada; Kentaro Omura; Shigeki Horiuchi, Earth, Planets and Space, 70, 01 Dec. 2018
• 山陰ひずみ集中帯における最近の地殻変動と測地・地震・地質学的ひずみ速度の比較
  西村 卓也; 高田陽一郎, 地球惑星科学関連連合2016年連合大会, May 2016
  Japanese, Summary national conference
• The San-in shear zone in southwest Japan revealed by the GEONET data
  NISHIMURA Takuya; TAKADA Youichiro, 2015 AGU Fall Meeting, Dec. 2015
  English, Summary international conference
• 国際測地学地球物理学連合2015年総会報告
  日置幸介; 飯沼卓史; 大坪俊通; 加藤照之; 高田陽一郎; 田中愛幸; 土井浩一郎; 西村卓也; 橋本 学; 福島登志夫; 福田洋一; 古屋正人; 松尾功二, 測地学会誌, 61, 173, 182, 2015, [Peer-reviewed]
  Japanese, Meeting report
• 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
• 地殻変動 巨大地震に伴う火山の沈降
  高田 陽一郎, JGL = 日本地球惑星科学連合ニュースレター : Japan geoscience letters, 10, 1, 8, 11, Feb. 2014
  日本地球惑星科学連合, Japanese
• ALOS-2による日本列島地殻変動マッピング：意義とチャレンジ
  橋本学; 福島洋; 高田陽一郎, ALOS2/3ワークショップ, 12 Dec. 2012
  Japanese
• 2011年4月11日いわき地震（Mw=6.6）のすべり分布インバージョン
  福島 洋; 高田陽一郎; 橋本 学, 日本測地学会第116回講演会, 28 Oct. 2011
  Japanese
• ALOS/PALSARで見た東日本大震災
  橋本学; 福島洋; 高田陽一郎, 自然災害学会, Oct. 2011
  Japanese
• InSARによる誘発された内陸地殻変動の検出
  高田陽一郎; 福島洋; 橋本学, 地球惑星科学連合2011年大会, 24 May 2011
  Japanese
• ALOS/PALSARで捕らえた世界の大地震：２０１０年
  橋本学; 福島洋; 高田陽一郎; 岡本淳一, 平成２２年度京都大学防災研究所研究発表講演会, 23 Feb. 2011
  Japanese
• Locations and types of ruptures involved in the 2008 Sichuan earthquake inferred from SAR image matching (vol 36, L07302, 2009)
  Tomokazu Kobayashi; Youichiro Takada; Masato Furuya; Makoto Murakami, GEOPHYSICAL RESEARCH LETTERS, 36, May 2009
  English, Others

• Seismic Response of Large Calderas to Great Earthquakes and Implications for Rheology
  Youichiro Takada
  SGEPSS Conductive Anomaly (CA) 研究会, 18 Mar. 2026, Japanese, Invited oral presentation
  17 Mar. 2026 - 18 Mar. 2026, [Invited]
• Volcanic subsidence triggered by the 2011 Tohoku earthquake in Japan: Hot and weak material hypothesis
  European Geosciences Union General Assembly 2014, 29 Apr. 2014, European Geosciences Union, English, Invited oral presentation
  [Invited]
• ヒマラヤ・チベット地域に関する地球物理学的観測量と数値モデル
  日本地質学会 第117年学術大会, 19 Sep. 2010, 日本地質学会, Japanese, Invited oral presentation
  [Invited]
• Insights into earthquake generation and topographic evolution in and around the Kurikoma geothermal area, NE Japan.
  Western Pacific Geophysics Meeting (WPGM), 23 Jun. 2010, American Geophysical Union, English, Invited oral presentation
  [Invited]
• A scenario of tectonic evolution in Taiwan: insight into the time development of the 3-D basement structure consistent with relative plate motion
  International Workshop on Tectonics of Plate Convergence Zones: Toward the Seamless Understandings from Earthquake cycles to Gemorphic Evolution, 29 Sep. 2006, University of Tokyo, English, Invited oral presentation

• 衛星測地学特論, 2024年, 修士課程, 理学院
• 地球惑星科学実験Ⅳ, 2024年, 学士課程, 理学部
• 固体地球惑星物理学, 2024年, 学士課程, 理学部
• 地球連続体力学, 2024年, 学士課程, 理学部
• 現代地球惑星科学概論２, 2024年, 学士課程, 理学部

• InSARと超稠密GNSSを用いた大規模カルデラにおけるレオロジー構造の推定
  科学研究費助成事業
  Apr. 2025 - Mar. 2028
  高田陽一郎
  日本学術振興会, 基盤研究(C), 北海道大学, Principal investigator
• Postseismic model for predicting crustal deformation and seismicity after the Tohoku-oki earthquake
  Apr. 2023 - Mar. 2027
  武藤潤; 飯沼 卓史; 岡田 知己, 太田 雄策, 高田陽一郎
  JSPS, 基盤研究(B), 東北大学, Coinvestigator, 23K25958
• Interaction between fault slip and viscous fluid in hypocentral area of inland earthquakes
  Grants-in-Aid for Scientific Research
  01 Apr. 2022 - 31 Mar. 2025
  高田 陽一郎
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, 22K03770
• Is the diversity of fault slip defined by structural heterogeneity?
  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
  01 Apr. 2019 - 31 Mar. 2022
  吉村 令慧; 小川 康雄; MORI JamesJiro; 高田 陽一郎
  すべりの多様性がみられる２つの断層（トルコ：北アナトリア断層帯Bolu-Geredeセグメント、日本：跡津川断層）において、その多様性に対応する比抵抗構造の不均質性がみられるか、見られたとして共通性があるか否かを明らかにすることが研究目的である。2019年度は、主に日本国内において跡津川断層周辺で稠密な広帯域電磁探査を実施した。43地点において、各7日～10日間器材を設置し電磁場データを連続で収録した。1か所を除き良質な記録が得られ時系列処理を進めている。観測効率を上げるために、電場磁場5成分を収録する観測点（23点）と電場2成分（20点）のみを収録する観測点に分けて実施した。また、本研究において導入した低コストの電磁場収録ロガーについて、動作確認を行い、既存機器と同程度な機能を有することを確認した。本研究では既存のデータも活用するが、既存データの整理も進めた。
  2020年度実施予定のトルコでの調査に備え、現地訪問を行い現地研究協力者との打合せを行い、実施時のロジスティクスならびに観測消耗品の事前準備を進めた。
  地殻変動については、北アナトリア断層Bolu-Geredeセグメントにおいて、ALOS-2のScanSARモードで撮像したSAR画像を用いて予備的なInSAR解析を行い、撮像時期が4年離れたペアの干渉性を調べた。また、現在の当該地域の地震活動を把握するために、現地訪問や遠隔打合せを活用し、トルコ国内研究者によって取得された既存のデータについての情報を収集した。追加の地震観測などの必要性について検討を進めた。
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Kyoto University, 19H01992
• 東日本の島弧地殻における非弾性変形マッピング
  科学研究費補助金（基盤B）
  Apr. 2018 - Mar. 2021
  鷺谷威
  文部科学省, Competitive research funding
• 異なる測地技術を統合した非地震性地殻変動の検出
  科学研究費補助金（基盤C）
  2017 - 2020
  高田 陽一郎
  文部科学省, Principal investigator, Competitive research funding
• 地殻ダイナミクスー東北沖地震後の内陸変動の統一的理解ー
  科学研究費補助金（新学術領域研究）
  2014 - 2019
  飯尾能久
  文部科学省, Competitive research funding
• 異なる時空間スケールにおける日本列島の変形場の解明
  科学研究費補助金（新学術領域研究）
  2014 - 2019
  鷺谷威
  文部科学省, Competitive research funding
• A new non-linear inversion approach: Applications for various research areas from waveforms and 2-D images
  Grants-in-Aid for Scientific Research
  Apr. 2016 - Mar. 2018
  Yomogida Kiyoshi; YOICHIRO TAKADA; RYOU HONDA
  We have developed a new approach to compare waveform records with a criterion in the use of the time-domain Wiener filter, in order to remove the non-uniqueness originated from the periodicity in phase information. In the case of a short record length (e.g., multiple ScS phases on the core-mantle boundary of the earth), our approach can estimate broadband results accurately, compared with conventional spectral ratios. Another example in this study is the estimation of seismic anisotropy in the crust with the S-wave splitting of two horizontal-component records. In additional to the azimuth of splitting, our approach can estimate the time delay or the strength of anisotropy accurately, not resolved in a quantitative manner yet in previous studies. These results imply that our new approach is not only powerful for seismic waveform data, as shown in this study, but also any waveform records in a wide range of research areas, including two-dimensional image data in space.
  Japan Society for the Promotion of Science, Grant-in-Aid for Challenging Exploratory Research, Hokkaido University, 16K13869
• Crustal deformation in and around the Hida mountain range revealed by space geodetic technologies
  Grants-in-Aid for Scientific Research
  2014 - 2016
  Takada Youichiro
  Combining GNSS surveys and InSAR time-series analyses, we obtained high spatial resolution images of inter-seismic velocity field in and around the Hida mountain range, especially for the Atotsugawa fault system. So far, InSAR has been applied to detect inter-seismic crustal deformation for arid regions and/or fault creeps along large scale active faults. In this study, we successfully applied InSAR analysis to humid areas covered with dense vegetation in summer and large amount of snow in winter. We revealed that, among three fault strands consisting of the Atotsugawa fault system, displacement gradient takes maximum in proximity of the Ushikubi fault. Through our work, it becomes possible to detect heterogeneous velocity field inside strain concentration zones.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), 京都大学, Principal investigator, Competitive research funding, 26400454
• The lower crust immediately below intraplate earthquake faults is weak? –A dense seismic observation in the northern part of the South Island in New Zealand-
  Grants-in-Aid for Scientific Research
  Apr. 2011 - Mar. 2015
  IIO YOSHIHISA; OKADA Tomomi; MATSUMOTO Satoshi; OHMI Shiro; FUKAHATA Yukitoshi; TAKADA Youichiro; YAMADA Masumi; KOSUGA Masahiro
  We conducted a dense seismic observation in the northern part of the South Island in New Zealand, and found anomalous seismic velocity structures immediately below intraplate earthquake faults, which is in accordance with the resistivity structures. This fact supports a model for the generating process of intraplate earthquakes, that the lower crust immediately below intraplate earthquake faults is weakened by water. Furthermore, we conducted an aftershock observation for the Christchurch earthquake, and estimated detailed aftershock distributions and velocity structures. It is suggested from the characteristic depth distributions of aftershock hypocenters that stress concentration occurred around the western end of the earthquake fault.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), Kyoto University, 23253004
• Volcanic subsidence caused by megathrust earthquakes
  Grants-in-Aid for Scientific Research
  2012 - 2013
  TAKADA Youichiro
  I have detected that five volcanic regions (Akitakoma, Kurikoma, Zao, Azuma, and Nasu) subsided in response to the crustal deformation associated with the 2011 Tohoku earthquake (Mw 9.0). A common feature of five subsided volcanoes is their high geothermal activity, which indicates the existence of hot and weak plutonic body beneath there. I have calculated the surface deformation above the weak material caused by coseismic stress change. The synthetic surface deformation obtained from optimal shape and location of the weak material well explains the InSAR data. The surface subsidence gets larger when the weak body is elongated in the direction perpendicular to the extensional principal axis of coseismic stress change. GPS data indicate that the subsidence has completed in one day after the main shock at most. Therefore, the ground water movement is unlikely to directly cause the volcanic subsidence.
  Japan Society for the Promotion of Science, Grant-in-Aid for Young Scientists (B), Kyoto University, Principal investigator, Competitive research funding, 24740305
• Deciphering deformation styles of inland plate boundaries by InSAR
  Grants-in-Aid for Scientific Research
  2007 - 2009
  FURUYA Masato; TAKADA Youichiro
  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 explained by a single rectangular fault even with distributed slip, which suggest that a geometric complexity is a universal character of inland earthquakes. In the Onikobe and Chuetsu-oki events, we also detected significant signals outside the main shock fault that were attributed to aseismic fault motion.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 19340123
• 大陸衝突帯における大地形の形成:断層系の時間発展と侵食・堆積の相互作用
  科学研究費助成事業
  2003 - 2005
  高田 陽一郎
  大陸衝突帯における大地形の形成は大陸プレート同士の収束運動に起因する。収束運動に伴うプレート間の力学的相互作用はプレート境界面での変位の食い違い運動(すべり)で合理的に表現される。このすべりに伴う地殻変動が大地形の成長に直接的に寄与している。一方、長い時間スケールでの侵食・堆積作用は地表荷重の変化を通じて地殻内応力場を変え、プレート境界断層系の形状をも変える。本研究の目的は侵食・堆積作用がこのフィードバックプロセスにどう影響して、地形形成過程をどう改変するのかを定量的に理解することである。
  本年は、米国コロラド大学でPeter Molnar教授と共同研究を行い、圧縮応力場において非線形成層構造媒質中に周期的不安定が発達する際に、侵食・堆積作用がどのような影響を与えるかを数値的に明らかにした。この研究は断層の発生に先立つせん断応力の蓄積が侵食・堆積作用から受ける影響を知る上で重要である。計算結果から、侵食・堆積作用は重力の効果を弱め、より長い波長の褶曲を発達させ、更にその発達速度を速めることが分かった。基盤層の実効粘性率が表層のそれより遥かに低い場合には、侵食・堆積作用の影響が非常に大きくなることも明らかになった。
  このモデルはスケールされているので、アセノスフェア、下部地殻、岩塩層等の低粘性層の存在下での様々なスケールの問題に適用できる。この成果はJournal of Geophysical Researchに投稿予定である。その後、英国Oxford大学において、進行中の褶曲発達過程や断層形状発達過程に関する豊富な衛星データを活用して、イランやチベットについてモデルの検証に取り組んだ。
  また、大陸衝突帯の中でもとりわけ断層運動に伴う隆起と侵食作用が活発な台湾島について、粘土モデルを用いて地下構造(断層形状)発達史を昨年度よりさらに詳細に研究し、成果をTectonicsに投稿した。
  日本学術振興会, 特別研究員奨励費, 北海道大学, 03J09575
• 大陸衝突帯における大地形の形成:プレート間相互作用と断層系の発達
  科学研究費助成事業
  2001 - 2002
  高田 陽一郎
  収束運動に伴うプレート間の力学的相互作用はプレート境界面での変位の食い違い運動で合理的に表現される。これまでの研究では変位の食い違いが生じる断層面の形状を固定して考えていたが、実際の断層は地質学的時間を経て変形するはずである。本研究では、断層面が自身のすべりや外部荷重の変化に伴いどのような形状変化及び分岐を生じるのか、そしてその結果、大陸衝突帯の大地形がどのように形成されるのかを明らかにする。
  今年度は昨年度の成果を土台として研究を開始し、分岐断層が主断層から分岐する点が時間とともに移動する効果をより現実的に考慮した数値計算を行った結果、昨年度に得られた成果が定性的には変わらないことをより確かな物とし、定量的な面ではこれを改良することができた。次に、媒質の破壊を伴う断層の形状進化を理解するために、プレート境界面浅部が定常的にすべり遅れた場合に定常的に蓄積する広域内部応力場を計算した。その結果、多くの大陸衝突帯に普遍的に見られる分岐断層群のパターンと調和的な応力蓄積速度場の計算結果を得た。
  さらに、ヒマラヤを含む一般的な大陸衝突型造山帯の地形形成過程の解明を一層進めるために、最も活発な大陸衝突帯の一つである台湾島の形成過程を粘土モデルを用いて研究した。このモデルにおいては特にプレート境界断層系の発達を合理的に取り入れることを重要な要素として取り扱った。その結果、地球物理学、測地学、地質学、地形学の諸観測量を合理的に説明する台湾島形成のシナリオを作り上げることに成功した。この成果を地球惑星科学関連合同大会、および西太平洋地球物理会議(Western Pacific Geophysics Meeting)で発表した。この成果を論文にとりまとめて国際誌に投稿する。
  日本学術振興会, 特別研究員奨励費, 東京大学, 01J05949