The Whole Pictures of the Kanto Earthquake Sequence Revealed by Historical Seismograms

• Project/Area Number: 18H01289
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 17030:Human geosciences-related
• Research Institution: The University of Tokyo
• Principal Investigator: MIYAKE Hiroe 東京大学, 地震研究所, 准教授 (90401265)
• Co-Investigator(Kenkyū-buntansha): 室谷 智子 独立行政法人国立科学博物館, 理工学研究部, 研究主幹 (40646593) ; 纐纈 一起 東京大学, 地震研究所, 名誉教授 (90134634)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Project Status: Completed (Fiscal Year 2021)
• Budget Amount: ¥15,600,000 (Direct Cost: ¥12,000,000、Indirect Cost: ¥3,600,000); Fiscal Year 2020: ¥3,510,000 (Direct Cost: ¥2,700,000、Indirect Cost: ¥810,000); Fiscal Year 2019: ¥6,370,000 (Direct Cost: ¥4,900,000、Indirect Cost: ¥1,470,000); Fiscal Year 2018: ¥5,720,000 (Direct Cost: ¥4,400,000、Indirect Cost: ¥1,320,000)
• Keywords: 関東地震 / 古記録 / 震度 / 震源インバージョン / 強震動シミュレーション

Outline of Final Research Achievements

The 1923 Kanto earthquake is associated with at least four M7-class aftershocks in and around the mainshock source region. This study investigated historical seismograms to reveal the seismic sources of the Kanto earthquake sequence, and tried to reproduce historical seismic intensity distribution as a sum of the Kanto earthquake sequence. We confirmed clear teleseismic waveforms with surface waves of the M7.3 aftershock that occurred a day after the mainshock. We also tested several cases for aftershocks with different locations and magnitudes to simulate the historical seismic intensity distribution.

Academic Significance and Societal Importance of the Research Achievements

学術的意義としては、これまであまり着目されておらず、地震規模や震源位置について議論が残されている、1923年関東地震のマグニチュード7クラスの余震を分析したこととが挙げられる。また、これらの余震の分析には、翌年1924年に発生した丹沢の地震との比較検討が有効であることを確認した。
社会的意義としては、大地震が発生し強震動にさらされた堆積平野においては、一時的に震度増分が経験式よりも増える事例があるため、地震ハザードにおいて考慮すべき可能性を指摘した。

Research Products

• [Int'l Joint Research] カリフォルニア大学バークレー校(米国)
• [Int'l Joint Research] カリフォルニア大学バークレー校(米国)
• [Int'l Joint Research] カリフォルニア大学バークレー校(米国)
• [Journal Article] Recipe for strong ground motion prediction: Current and future (2021)
  • Author(s): Miyake, H., K. Irikura, H. Fujiwara, N. Morikawa, T. Maeda, A. Iwaki, and A. Pitarka
  • Journal Title: The 6th IASPEI/IAEE International Symposium: Effects of Surface Geology on Seismic Motion Volume: -
  • Int'l Joint Research
• [Journal Article] Similarities and Differences in the Rupture Processes of the 1952 and 2003 Tokachi‐Oki Earthquakes (2021)
  • Author(s): Kobayashi Hiroaki、Koketsu Kazuki、Miyake Hiroe、Kanamori Hiroo
  • Journal Title: Journal of Geophysical Research: Solid Earth Volume: 126 Issue: 1
  • DOI: 10.1029/2020jb020585
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] 東京大学地震研究所の強震観測 (2020)
  • Author(s): 三宅弘恵・纐纈一起・古村孝志・宮川幸治・安藤美和子・八木健夫
  • Journal Title: 地震（ニュースレター部） Volume: 73(NL1) Pages: 10-13
  • Open Access
• [Journal Article] 首都圏強震動総合ネットワークSK-net (2020)
  • Author(s): 三宅弘恵・上原美貴・鶴岡弘・鷹野澄・纐纈一起
  • Journal Title: 地震（ニュースレター部） Volume: 73(NL3) Pages: 13-15
  • Open Access
• [Journal Article] Recipe for predicting strong ground motion on the SCEC Broadband Platform (2020)
  • Author(s): Miyake, H., A. Pitarka, A. Iwaki, N. Morikawa, T. Maeda, H. Fujiwara
  • Journal Title: Proceedings of the 17th World Conference on Earthquake Engineering Volume: -
  • Int'l Joint Research
• [Journal Article] A database of digitized and analog seismograms of historical earthquakes in Japan (2020)
  • Author(s): Murotani, S., K. Satake, H. Tsuruoka, H. Miyake, T. Sato, T. Hashimoto, and H. Kanamori
  • Journal Title: Seismol. Res. Lett. Volume: 91 Issue: 3 Pages: 1459-1468
  • DOI: 10.1785/0220190287
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] 強震動予測の震源モデル化の現状 (2019)
  • Author(s): 三宅弘恵・森川信之
  • Journal Title: 第47回地盤震動シンポジウム Volume: - Pages: 41-44
• [Journal Article] Characterized source modeling of crustal earthquakes for broadband ground motion prediction (2018)
  • Author(s): Miyake, H., and K. Irikura
  • Journal Title: Best Practices in Physics Based Fault Rupture Models for Seismic Hazard Assessment of Nuclear Installations, IAEA-TECDOC-CD-1833 Volume: -
  • Open Access
• [Journal Article] 東京大学地震研究所の強震観測網と強震観測データベース (2018)
  • Author(s): 三宅弘恵・纐纈一起・古村孝志・宮川幸治・田中伸一
  • Journal Title: 第15回日本地震工学シンポジウム論文集 Volume: - Pages: 3306-3311
• [Journal Article] Irregular modes of rupture directivity found in recent and past damaging earthquakes (2018)
  • Author(s): Koketsu, K., H. Kobayashi, and H. Miyake
  • Journal Title: Proceedings of the 11th U.S. National Conference on Earthquake Engineering Volume: -
• [Presentation] 国立科学博物館が所蔵する関東大震災の油絵・写真 (2021)
  • Author(s): 室谷智子
  • Organizer: 第38回歴史地震研究会
• [Presentation] Earthquake source characterization for broadband ground motion simulation (2021)
  • Author(s): Miyake, H.
  • Organizer: PEER International Pacific Rim Forum
  • Int'l Joint Research / Invited
• [Presentation] Characterization of extreme ground motions (2021)
  • Author(s): Miyake, H.
  • Organizer: JpGU Meeting 2021
  • Int'l Joint Research
• [Presentation] Near-surface velocity reduction and anisotropy for early aftershocks revealed by coda interferometry (2021)
  • Author(s): Miyake, H., T. Taira, L.-W. Chen
  • Organizer: 2021 AGU Fall Meeting
  • Int'l Joint Research
• [Presentation] Seismic intensity simulation of the entire 1923 Kanto earthquake sequence (2020)
  • Author(s): Miyake, H., S. Murotani, and K. Koketsu
  • Organizer: 日本地震学会 2020年度秋季大会
• [Presentation] Impact of seismic velocity change on ground motion modeling (2020)
  • Author(s): Miyake, H., T. Taira, and L.-W. Chen
  • Organizer: JpGU-AGU Joint Meeting 2020
  • Int'l Joint Research
• [Presentation] 日本の被害地震波形記録の数値化・画像化データベース (2020)
  • Author(s): 室谷智子・佐竹健治・鶴岡弘・三宅弘恵・橋本徹夫・佐藤俊明・金森博雄
  • Organizer: 日本地震学会2020年秋季大会
• [Presentation] Revisiting historical seismograms of the 1923 M7.9 Kanto earthquake and aftershocks (2019)
  • Author(s): Murotani, S., H. Miyake, and T. Taira
  • Organizer: 2019 AGU Fall Meeting
  • Int'l Joint Research
• [Presentation] Building a global seismic hazard map, Big Data Visualization: A New Era in Mapping with the University of Tokyo (2019)
  • Author(s): Miyake, H.
  • Organizer: Annual Meeting of the New Champions (AMNC 2019)
  • Int'l Joint Research / Invited
• [Presentation] Efforts of science museum to preserve historical materials and data for seismology: Taking the 1923 Kanto earthquake as an example (2019)
  • Author(s): Murotani, S.
  • Organizer: IUGG 2019
  • Int'l Joint Research