Revisiting the three M-7 Miyagi-oki earthquakes in the 1930s: possible seismogenic slip on asperities that were re-ruptured during the 1978 M=7.4 Miyagi-oki earthquake

• Umino Norihito

  Research Center for Prediction of Earthquakes and Volcanic Eruptions, Graduate School of Science, Tohoku University

• Kono Toshio

  Research Center for Prediction of Earthquakes and Volcanic Eruptions, Graduate School of Science, Tohoku University

• Okada Tomomi

  Research Center for Prediction of Earthquakes and Volcanic Eruptions, Graduate School of Science, Tohoku University

• Nakajima Junichi

  Research Center for Prediction of Earthquakes and Volcanic Eruptions, Graduate School of Science, Tohoku University

• Matsuzawa Toru

  Research Center for Prediction of Earthquakes and Volcanic Eruptions, Graduate School of Science, Tohoku University

• Uchida Naoki

  Research Center for Prediction of Earthquakes and Volcanic Eruptions, Graduate School of Science, Tohoku University

• Hasegawa Akira

  Research Center for Prediction of Earthquakes and Volcanic Eruptions, Graduate School of Science, Tohoku University

• Tamura Yoshiaki

  National Astronomical Observatory of Japan

• Aoki Gen

  Sendai District Meteorological Observatory

Bibliographic Information

Other Title

• Revisiting the three M ∼ 7 Miyagi-oki earthquakes in the 1930s: possible seismogenic slipon asperities that were re-ruptured during the 1978 M7.4 Miyagi-oki earthquake

Abstract

Hypocenters of main shocks and aftershocks of the 1933 M=7.1, 1936 M=7.4, 1937 M=7.1 and 1978 M=7.4 Miyagi-oki earthquakes are relocated using S-P times reported in the Seismological Bulletin of the Japan Meteorological Agency (JMA) and those re-read from original smoked-paper seismograms observed at the Mizusawa station of the National Astronomical Observatory of Japan (NAOJ) and the Mukaiyama station of Tohoku University. In order to reduce the error caused by inaccuracies of the arrival times and the small number of seismic observation stations, we determined the hypocenters by using a grid search method that assumed that the events occurred at the boundary between the subducting Pacific plate and the overriding plate. The main shock epicenters of these four earthquakes were determined to be close to each other, while the distributions of their aftershocks seem to disperse on the upper boundary of the Pacific plate. These distributions show that aftershock areas of the 1933, 1936 and 1937 events partly overlap with that of the 1978 event and occupy its easternmost, central and westernmost portions, respectively. This result suggests that the 1933, 1936 and 1937 events possibly ruptured a part of the source area of the 1978 event, i.e., its eastern, central and western portions, respectively.

Journal

• Earth, Planets and Space

  Earth, Planets and Space 58 (12), 1587-1592, 2006

  Society of Geomagnetism and Earth, Planetary and Space Sciences, The Seismological Society of Japan, The Volcanological Society of Japan , The Geodetic Society of Japan , The Japanese Society for Planetary Sciences

Keywords

• Miyagi-oki earthquake
• asperity
• interplate earthquake
• subduction zone
• smoked-paper seismogram

Details

• CRID: 1390282681488746624
• NII Article ID: 10024495727
• NII Article ID: 130003956573
• NII Book ID: AA11211921
• DOI: 10.1186/bf03352666
• ISSN: 18805981
• ISSN: 13438832
• NDL BIB ID: 8648786
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I8648786
• Web Site: https://link.springer.com/content/pdf/10.1186/BF03352666.pdf
• Web Site: https://link.springer.com/article/10.1186/BF03352666/fulltext.html
• Web Site: http://link.springer.com/content/pdf/10.1186/BF03352666
• Text Lang: en
• Data Source:
  • JaLC
  • NDL
  • Crossref
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Disallowed