2018 Fiscal Year Annual Research Report
| Project Area | Science of slow earthquakes |
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| Project/Area Number |
16H06476
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| Research Institution | University of Tsukuba |
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Principal Investigator |
氏家 恒太郎 筑波大学, 生命環境系, 准教授 (40359188)
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| Co-Investigator(Kenkyū-buntansha) |
片山 郁夫 広島大学, 理学研究科, 教授 (10448235)
森 康 北九州市立自然史・歴史博物館, 自然史課, 学芸員 (20359475)
WALLIS R・Simon 東京大学, 大学院理学系研究科(理学部), 教授 (30263065)
橋本 善孝 高知大学, 教育研究部自然科学系理工学部門, 教授 (40346698)
谷川 亘 国立研究開発法人海洋研究開発機構, 超先鋭研究開発部門(高知コア研究所), 主任研究員 (70435840)
堤 昭人 京都大学, 理学研究科, 准教授 (90324607)
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| Project Period (FY) |
2016-06-30 – 2021-03-31
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| Keywords | 付加体 / 変成岩 / 摩擦実験 |
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| Outline of Annual Research Achievements |
(A)スロー地震の地質学的描像
四万十付加体槇峰メランジュ及び西彼杵変成岩を対象に、地質調査、EBSDによる結晶方位解析、XRFによる全岩化学組成分析を行った、その結果、深部スロー地震発生深度では、交代作用に関連して脱水が起こり、水圧破砕や粘性剪断変形の局所化・歪速度の増加をもたらしていることを明らかにした。三波川帯中に露出するウェッジマントル起源の蛇紋岩体の地質構造と岩石学的特徴を検討し、深さ約40 kmではアンチゴライトの定向配列で特徴付けられる剪断帯の発達とそれに伴う流体圧上昇が、深さ約30 km以浅では脆性変形が卓越していることを明らかにした。また、FTIRを用いて蛇紋岩組織を可視化するための新しい手法を開発した。更に、沈み込み帯における剪断応力による剪断熱の影響を評価するための数値モデリングを行い、高応力と低応力の沈み込み型変成帯を識別する方法を提案した。陸上付加体で実施されている構造地質学的手法を紀伊半島沖南海トラフプレート境界断層に応用し、slip tendencyのマップを作成し、slip tendencyの高い地域が超低周波地震の発生域と一致することを見出した。
(B)スロー地震の摩擦・水理特性
沈み込み帯プレート境界域の代表的鉱物である粘土鉱物の摩擦特性を検討し、摩擦係数や摩擦の速度依存性が水の有無によって影響を受けることを明らかにした。生物起源堆積物を用いた摩擦実験を行い、3 mm/sより高速の条件で顕著なすべり弱化とそれに引き続くゆっくととしたすべり強化の挙動が見られることを明らかにした。この挙動は、母岩に透水性の高い岩石を用いると現れないことから、すべりに伴う断層帯内部での間隙水圧変動に起因していることが示唆された。模擬断層物質を用いた摩擦透水実験を実施し、すべり速度透水性の変動がスロー地震や地震サイクルに影響を及ぼしていることを明らかにした。
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
(A)スロー地震の地質学的描像
A01, 02班とB02班が明らかにした沈み込み帯Episodic Tremor and Slipの観測結果を説明する地質モデル（クラックシール剪断脈と粘性剪断帯の共存）を提示し、論文公表した。この論文は、高い被引用数と関心をもたらしている。学会発表も数多く行われ、内容は研究成果に関するものから研究手法開発に至るものまで多岐に渡る。論文執筆も進んでおり、投稿に向けた準備がほぼ整いつつある。
(B)スロー地震の摩擦・水理特性
粘土鉱物や生物起源堆積物の摩擦特性を決定づける要因が明らかになってきた。これにより、スロー地震の発生要因の理解が進んだ。摩擦試験機の開発に関しては、データの再現性を確かめているところである。南海トラフ掘削試料を用いた研究に関しては、プレート境界断層に到達できなかったため、カッティングスを用いた研究に変更して進めている。論文執筆も進んでおり、投稿に向けた準備がほぼ整いつつある。
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| Strategy for Future Research Activity |
(A)スロー地震の地質学的描像
四万十付加体槇峰メランジュ及び西彼杵変成岩を対象とした地質調査、EBSDによる結晶方位解析、XRFによる全岩化学組成分析を継続し、交代作用に伴う脆性変形と粘性剪断歪速度の増加がそれぞれ深部微動とスロースリップにどのように対応しているか検討する。三波川帯を対象とした研究では、堆積岩起源の沈み込み型変成岩の分析を行い、岩石の体積変化や組成変化を検討し、プレート境界に沿った流体の流動様式と流体流動量を明らかにする。紀伊半島南海トラフプレート境界面上の弾性波速度分布から物性、流体圧および摩擦強度の不均質な分布を検討し、slip tendencyの分布との対比を行う。また、陸上付加体においても面的な地質調査から小断層のslip tendencyの分布を検討し、現在の南海トラフの結果と対比する。
(B)スロー地震の摩擦・水理特性
断層ガウジ試料の剪断変形中に弾性波速度ならびに比抵抗を計測し，断層ガウジ内での構造変化に対応した物性変化を明らかにし、スロー地震が発生している断層面での物理状態の推定につなげる。沈み込み帯における断層物質の組成や透水性などの多様な性質や、すべり速度、間隙水圧、有効垂直応力などの条件が断層すべり安定性に及ぼす影響について実験を更に進め、沈み込み帯浅部断層の摩擦特性を明らかにする。摩擦透水実験で得られた摩擦透水パラメータ（透水係数と速度変化の関係）を用いて、C01, 02班と協力してスロー地震の発生シミュレーションを実施する。更に、南海掘削試料（カッティングス）を用いて透水性を評価する研究をまとめる。
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Research Products
(93 results)
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[Journal Article] Chitinozoans and scolecodonts from the Silurian and Devonian of Japan2019
Author(s)
Vandenbroucke, T. O. Hints, M. Williams, S. Wallis, J. Velleman, T. Kurihara, G. Tanaka, T. Komatsu, P. Mannik, D. Siveter, and T. de Backer
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Journal Title
Island Arc
Volume: 28
Pages: e12294:1-13
DOI
Peer Reviewed
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[Journal Article] The paleobiogeographical significance of the Silurian and Devonian trilobites of Japan2019
Author(s)
Stocker, C.P., D.J. Siveter, P.D. Lane, M. Williams, T. Oji, S. Wallis, G. Tanaka, T. Komatsu, D. Siveter, T. Vandenbroucke
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Journal Title
Island Arc
Volume: 28
Pages: e12287:1-15
DOI
Peer Reviewed
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[Journal Article] Normal faults at depth with thrust faults in an exhumed accretionary complex, Kayo Formation, Okinawa islands, Japan2018
Author(s)
Hashimoto, Y., D. Ueda, Y. Motomiya, K. Tobe, A. Saiki, K. Morita, and K. Ujiie
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Journal Title
Geological Society of America Special Papers
Volume: 534
Pages: 175-185
DOI
Peer Reviewed
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[Journal Article] Thermal conductivity changes of subducting basalt, Nankai subduction zone, SW Japan: An estimation from laboratory measurements under high-pressure and high-temperature conditions2018
Author(s)
Lin, W., O. Tadai, M. Kinoshita, J. Kameda, W. Tanikawa, T. Hirose, Y. Hamada, and O. Matsubayashi
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Journal Title
Geological Society of America Special Papers
Volume: 534
Pages: 34-50
DOI
Peer Reviewed
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[Journal Article] A Seismogeodetic Amphibious Network in the Guerrero Seismic Gap, Mexico2018
Author(s)
Cruz-Atienza, V. M., Y. Ito, V. Kostoglodov, V. Hjorleifsdottir, A. Iglesias, J. Tago, M. Calo, J. Real, A. Husker, S. Ide, T. Nishimura, M. Shinohara, C. Mortera‐Gutierrez, S. Garcia, and M. Kido
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Journal Title
Seismological Research Letters
Volume: 89
Pages: 1435-1449
DOI
Peer Reviewed / Int'l Joint Research
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[Journal Article] Along-arc heterogeneity of the seismic structure around a large coseismic shallow slip area of the 2011 Tohoku-oki Earthquake: 2-D Vp structural estimation through an airgun-ocean bottom seismometer experiment in the Japan Trench subduction zone2018
Author(s)
Azuma, R., R. Hino, Y. Ohta, Y. Ito, K. Mochizuki, K. Uehira, Y. Murai, T. Sato, T. Takanami, M. Shinohara, and T. Kanazawa
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Journal Title
Journal of Geophysical Research
Volume: 123
Pages: 5249-5264
DOI
Peer Reviewed
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[Journal Article] Development of a Slow Earthquake Database2018
Author(s)
Kano, M., N. Aso, T. Matsuzawa, S. Ide, S. Annoura, R. Arai, S. Baba, M. Bostock, K. Chao, K. Heki, S. Itaba, Y. Ito, N. Kamaya, T. Maeda, J. Maury, M. Nakamura, T. Nishimura, K. Obana, K. Ohta, N. Poiata, B. Rousset, H, Sugioka, R. Takagi, T. Takahashi, A. Takeo, Y. Tu, N. Uchida, Y. Yamashita, and K. Obara
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Journal Title
Seismological Research Letters
Volume: 89
Pages: 1566-1575
DOI
Peer Reviewed / Int'l Joint Research
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[Journal Article] Earthquakes and Tremor Linked to Seamount Subduction During Shallow Slow Slip at the Hikurangi Margin, New Zealand2018
Author(s)
Todd, E.K., S.Y. Schwartz, K. Mochizuki, L. M. Wallace, A. F. Sheehan, S. C. Webb, C. A. Williams, J. Nakai, J. Yarce, B. Fry. S. Henrys, and Y. Ito
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Journal Title
Journal of Geophysical Research
Volume: 123
Pages: 6769-6783
DOI
Peer Reviewed / Int'l Joint Research
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[Journal Article] Seafloor crustal deformation on ocean bottom pressure records with non-tidal variability corrections: application to Hikurangi margin, New Zealand,2018
Author(s)
Muramoto, T., Y. Ito, D. Inazu, L. M. Wallace, R. Hino, S. Suzuki, S. C. Webb, S. Henrys
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Journal Title
Geophysical Research Letters
Volume: 46
Pages: 303-310
DOI
Peer Reviewed / Int'l Joint Research
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[Presentation] Preliminary results of lithostratigraphy in IODP Expedition 375: Hikurangi subduction margin coring and observatories2018
Author(s)
Hashimoto, Y., C. Oliveira, S. Kutterolf, F. Meneghini, A. Noda, H. Rabinowitz, M. Underwood, D. Saffer, L. Wallace, K. Petronotis,
Organizer
日本地球惑星科学連合2018年大会
Invited
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[Presentation] Lithostratigraphy of the Hikurangi Subduction Inputs: Results of Coring During IODP Expedition 3752018
Author(s)
Underwood, M., H. Rabinowitz, A. Noda, F. Meneghini, S. Kutterolf, Y. Hashimoto, C. Oliveira, D. Saffer, L. Wallace, P. Barnes, I. Pecher, K. Petronotis, L. LeVay, and Expedition 375 Scientists, Expedition 372 Scientists
Organizer
AGU Fall Meeting 2018
Int'l Joint Research
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[Presentation] Geochemical Constraints on Fluid-Rock Reactions, Fluid Sources, and Flow Pathways Along the IODP Expedition 375 Transect; Northern Hikurangi Margin2018
Author(s)
Solomon, E., A. Huepers, M. Luo, P. Malie, D. Saffer, M. Torres, L. Wallace, K. Petronotis, P. Barnes, I. Pecher, L. LeVay, and IODP Expedition 375 and Expedition 372 Scientist
Organizer
AGU Fall Meeting 2018
Int'l Joint Research
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[Presentation] Constraining the deformation history of the frontal wedge of Hikurangi Subduction Margin with analog modeling and bedding trends from borehole logging of IODP Expedition 3722018
Author(s)
Koge, H., D. McNamara, D. Gamboa, H.-Y. Wu, G. Kim, S. Cardona, U. Shanker, P. Barnes, I. Pecher, L. LeVay, D. Saffer, L. Wallace, K. Petronotis, A. Noda, J. Morgan, J. Ashi, A. Yamaguchi, Y. Yamada, Y. Hamada and Expedition 372 Scientists, Expedition 375 Scientists
Organizer
AGU Fall Meeting 2018
Int'l Joint Research
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[Presentation] Borehole stress indicators across the Hikurangi Subduction Margin: Preliminary insights from IODP Expedition 3722018
Author(s)
McNamara, D., , H.-Y. Wu, H. Lee, L. Wallace, G. Lee, K. Heeschen, J. Elger, D. Saffer, P. Barnes, I. Pecher, and IODP Expedition 372 & 375 Scientists
Organizer
AGU Fall Meeting 2018
Int'l Joint Research
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[Presentation] Validating a full-waveform inversion velocity model at the north Hikurangi subduction margin using IODP drilling data2018
Author(s)
Bell, R., M. Gray, J. Morgan, S. Henrys, D. Barker, N. Bangs, P. Barnes, L. Wallace, D. Saffer, K. Petronotis and Scientific Team of IODP Drilling Expedition 375 and Scientific Team of IODP Drilling Expedition 372 scientific team
Organizer
AGU Fall Meeting 2018
Int'l Joint Research
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[Presentation] The dynamics of shallow plate interface slip at the offshore Hikurangi subduction margin, New Zealand2018
Author(s)
Wallace, L., P. Barnes, D. Saffer, S. Henrys, D. Barker, D. Bassett, F. Tontini, Y. Kaneko, Y. Ito, K. Mochizuki, S. Webb, K. Clark, U. Cochran, N. Litchfield, C. Williams Jr, S. Ellis, B. Fry, E. Todd, R. Bell, K. Petronotis, I. Pecher, L. LeVay and IODP Expedition 372 and 375 Scientists
Organizer
AGU Fall Meeting 2018
Int'l Joint Research / Invited
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[Presentation] Frictional behavior of incoming sediment in the Hikurangi subduction zone at in-situ PT conditions2018
Author(s)
Rabinowitz, H. H. Savage, S. Shreedharan, M. Ikari, F. Meneghini, Y. Ito, H. Kitajima, L. Wallace, D. Saffer, K. Petronotis, and Expedition 372/375 Scientists
Organizer
AGU Fall Meeting 2018
Int'l Joint Research
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[Presentation] Magnetic fabrics of deformed soft sediments at the deformation front of the Hikurangi subduction margin2018
Author(s)
Greve, A., T. Kanamatsu, A. Fagereng, J. Morgan, M. Wang, H. Savage, M. Kars, X. Li, L. Wallace, D. Saffer, K. Petronotis, and Expedition 375 and 372 Scientists
Organizer
AGU Fall Meeting 2018
Int'l Joint Research
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[Presentation] Signatures of Brittle Deformation in a Shallow Fault in the Hikurangi Subduction Margin2018
Author(s)
Savage, H., G. Coffey, S. Shreedharan, P. Polissar, A. Fagereng, F. Meneghini, M. Wang, Y. Hashimoto, L. Wallace, D. Saffer, P. Barnes, I. Pecher, K. Petronotis, L. LeVay, and IODP Expedition 372/375 Scientists
Organizer
AGU Fall Meeting 2018
Int'l Joint Research
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[Presentation] Elastic moduli and physical properties of fault rock and protolith associated with SSEs at the Northern Hikurangi margin, NZ2018
Author(s)
Saffer, D., R. Bell, P. Barnes, L. Wallace, H. Kitajima, G. Moore, S. Han, I. Pecher, K. Petronotis, L. LeVay, and IODP Expedition 372 and 375 Scientists
Organizer
AGU Fall Meeting 2018
Int'l Joint Research
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[Presentation] IODP borehole observatories to monitor slow slip at the offshore Hikurangi subduction zone2018
Author(s)
Wallace, L., E. Solomon, P. Fulton, D. Saffer, K. Petronotis, H. Jannasch, E. Davis, B. Rhinehart, J. Van Hyfte, K. Grigar, P. Barnes, R. Bell, I. Pecher, L. LeVay and IODP Expedition 372 and 375 Science Parties
Organizer
AGU Fall Meeting 2018
Int'l Joint Research
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[Presentation] Compactive deformation in the incoming sedimentary section of the Hikurangi Subduction Margin, New Zealand: Constraints from seismic reflection data and IODP cores2018
Author(s)
Wang, M., P. Barnes, J. Morgan, R. Bell, A. Fagereng, H. Savage, D. Saffer, L. Wallace, K. Petronotis, and Shipboard Scientists from IODP Expeditions 372 and 375
Organizer
AGU Fall Meeting 2018
Int'l Joint Research
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[Presentation] Subduction-Related Strain in a Calcareous-Pelagic Shear Zone: Insights on Deformation at the Hikurangi Margin Plate Interface from the Input Sequence at Site U1520 and the Llanddwyn Island Shear Zone, Anglesey, U.K.2018
Author(s)
Leah, H., A. Fagereng, F. Meneghini, J. Morgan, H. Savage, M. Wang, D. Saffer, L. Wallace, K. Petronotis, and IODP Expedition 372 and 375 Science Parties
Organizer
AGU Fall Meeting 2018
Int'l Joint Research
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[Presentation] RESPONSE OF GAS HYDRATE SYSTEMS TO SUBDUCTION-ZONE PROCESSES ON THE NORTHERN HIKURANGI MARGIN, NEW ZEALAND2018
Author(s)
Pecher, I., P. Oluwunmi, A. Djeffal, N. Bangs, G. Crutchley, J. Mountjoy, H. Villinger, P. Barnes, K. Heeschen, B. Dugan, M. Reagan, G. Moridis, R. Archer, D. Saffer, L. Wallace, L. LeVay, K. Petronotis and Expedition 372 Scientists, Expedition 375 Scientists
Organizer
AGU Fall Meeting 2018
Int'l Joint Research
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[Presentation] Occurrence and fractionation of light hydrocarbons in the gas-hydrate bearing sediments of IODP Site U1517, Hikurangi Margin, New Zealand2018
Author(s)
Heeschen, K., M. Torres, I. Pecher, S. Schlomer, S. Owari, P. Rose, M. Karina, J. Schicks, G. Hu, J. Mountjoy, P. Barnes, L. LeVay, E. Solomon, D. Saffer, L. Wallace, K. Petronotis, IODP Expedition 372 Scientists and IODP Expedition 375 Scientists
Organizer
AGU Fall Meeting 2018
Int'l Joint Research
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[Presentation] Seafloor Overthrusting Creates Ductilely Deformed Fault Rocks in Marine Sediments at the Hikurangi Margin: Implications for Fault Zone Evolution and Mechanics at IODP Site U15182018
Author(s)
Morgan, J., A. Fagereng, H. Savage, M. Wang, F. Meneghini, P. Barnes, R. Bell, H. Kitajima, B. Dugan, L. Wallace, D. Saffer, I. Pecher, K. Petronotis, L. LeVay, IODP Expedition 372 Scientists and IODP Expedition 375 Scientists
Organizer
AGU Fall Meeting 2018
Int'l Joint Research
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[Presentation] Pore morphology, permeability, and constraints on gas hydrate accumulation in sediments from the Tuaheni Landslide Complex, NZ2018
Author(s)
Nole, M., H. Daigle, B. Dugan, M. Clennell, M. Paganoni, P. Barnes, I. Pecher, L. LeVay, IODP Expedition 372 Scientists and IODP Expedition 375 Scientist
Organizer
AGU Fall Meeting 2018
Int'l Joint Research
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[Presentation] Gas Hydrate Accumulations in Thin Sands2018
Author(s)
Wei, L., A. Cook, M. Nole, A. Malinverno, H. Daigle, A. Georgiopoulou, P. Barnes, I. Pecher, L. LeVay, IODP Expedition 372 Scientists and IODP Expedition 375 Scientists
Organizer
AGU Fall Meeting 2018
Int'l Joint Research
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[Presentation] Lithification of Volcaniclastic Deposits in the Hikurangi Subduction Zone: Preliminary Characterization of Fluid Circulation in the Incoming Plate, and Volatiles Entering the Trench2018
Author(s)
Meneghini, F., C. Boschi, A. Fagereng, J. Morgan, M. Underwood, Y. Hashimoto, C. Oliveira, S. Kutterolf, A. Noda, H. Rabinowitz, H. Savage, M. Wang, L. Wallace, D. Saffer, P. Barnes, I. Pecher, K. Petronotis, L. LeVay, and Scientific Team of IODP Exp 375 and 372
Organizer
AGU Fall Meeting 2018
Int'l Joint Research
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[Presentation] Frequent activity of shallow tectonic tremors in the southern margin of the 2011 Tohoku-Oki earthquake rupture area2018
Author(s)
Ohta, K., Y. Ito, S. Ohyanagi, R. Hino, Y. Ohta, R. Azuma, M. Shinohara, K. Mochizuki, T. Sato, and Y. Murai
Organizer
AGU Fall Meeting 2018
Int'l Joint Research
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