Abstract
On May 21, 1792, a gigantic collapse of Mt. Mayuyama in Shimabara Peninsula, Kyushu, occurred. Following this event, a severe tsunami of about 10 meters in height was generated by the landslide and attacked the coast of Ariake-kai, killing more than 14, 500 persons. Many historical documents tell us the phenomena of this tsunami in fair details, so that we attempted to reconstruct a numerical model of the tsunami consistent with the historical data. In the numerical computation, a finite difference method with a leap-frog system is adapted, and two kinds of source input are tried; one is the prescrived water mass transport normal to shore line and the other the vertical displacement of sea bottom. When the transport of 18, 000m3/min (current speed-20m/sec) per unit length of shore on the center line of landslide area is assumed to be continued during 2 to 4 min, the computed waves agree fairly well with the real tsunami behaviors, the height of tsunami in various places along the coast and the order of the maximum crest in the sequence of a wave train. Therefore, it seems probable that the extraordinary flow of water normal to the shore occurred by some physical mechanisms of the mountain collapse.The energy of this tsunami is estimated to be about 5×1019erg, and this is about 1/100-1/1000 of the available potential energy of the slided material due to the collapse of the mountain. It is significant that the tsunami energy is several times larger than that of the 1968 Hyuganada Earthquake (M=7.5). The wave spreaded over a wide area and gave distructive damages to the coast more than 120km on both side of Ariake-kai.
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Zisin (Journal of the Seismological Society of Japan. 2nd ser.)
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
