Japan Geoscience Union Meeting 2022

Presentation information

[J] Poster

M (Multidisciplinary and Interdisciplinary) » M-IS Intersection

[M-IS22] History X Earth and Planetary Science

Sun. May 29, 2022 11:00 AM - 1:00 PM Online Poster Zoom Room (28) (Ch.28)

convener:Yasuyuki Kano(Earthquake Research Institute, The University of Tokyo), convener:Kei Yoshimura(Institute of Industrial Science, The University of Tokyo), kiyomi iwahashi(kokugakuin university), convener:Harufumi Tamazawa(Kyoto City University of Arts), Chairperson:Yasuyuki Kano(Earthquake Research Institute, The University of Tokyo), Kei Yoshimura(Institute of Industrial Science, The University of Tokyo)

11:00 AM - 1:00 PM

[MIS22-P04] Examination of the seismic intensity of the earthquake that occurred in the Kinai region in September 1596

*Junzo Ohmura1, Yasuyuki Kano1 (1.Earthquake Research Institute,The University of Tokyo)

Keywords:Historical earthquakes, Seismic intensity, GIS

In September 1596, an earthquake of approximately M7.5 occurred in the Kinki region (Fushimi Earthquake). Trenching and archaeological investigations have confirmed that this earthquake was caused by the activity of the Arima-Takatsuki fault zone. In this study, we made a seismic intensity distribution map using the historical documents related to this earthquake, and compared it with the published seismic motion prediction map of the Arima-Takatsuki fault zone. As a result, it was found that the activity of the Arima-Takatsuki fault zone can explain the seismic intensity estimated from historical records. On the other hand, because of the lack of detailed records, it was concluded that it was impossible to determine whether the Rokko-Awaji fault zone was involved in this earthquake.
There have been many attempts to identify the earthquake fault based on the historical records of this earthquake. Among these studies, a series of studies conducted in the 1980s and 1990s have been criticized for underestimating the seismic intensity of the Osaka Plain and Osaka Bay area. In response to this point, this study examines what was wrong with the seismic intensity determination process in this study. As a result, it was found that the seismic intensity was underestimated based on the preconceived notion that the epicenter was in the Kyoto-Nara region. The damage at the contradictory points is forcibly explained by speculation that seismic wave amplification, liquefaction, and cliff slides occurred. The reason for the preconceptions may be due to the uneven distribution of sites and historical materials where damage is known.
The process of determining the seismic intensity of historical earthquakes is subjective, and the reliability of the obtained seismic intensity varies depending on the quantity and quality of the historical materials. Therefore, it is necessary to present data that allow a third party to verify the seismic intensity determination process, which will lead to the development of this field. The data to be released should include location information with an accuracy that can be used in simulations and the results of interpreting historical documents, and should be released as open data. The creation of such data requires the use of collective knowledge and a mechanism that enables the development of data based on discussions across disciplines.

The 1596 Kinai Earthquake (Coordinate data with estimated seismic intensity) https://github.com/ohmurajunzo/1596_Fushimi