Japan Geoscience Union Meeting 2021

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[J] Oral

M (Multidisciplinary and Interdisciplinary) » M-TT Technology & Techniques

[M-TT43] Brand-new scope of coupling geophysics being established by infrasound and associated waves

Sun. Jun 6, 2021 1:45 PM - 3:15 PM Ch.13 (Zoom Room 13)

convener:Masa-yuki Yamamoto(Department of systems engineering, Kochi University of Technology), Takayuki Otsu(Japan Weather Association), Mie Ichihara(Earthquake Research Institute, University of Tokyo), Nobuo Arai(Disaster Mitigation Research Center, Nagoya University), Chairperson:Yoshihiro Kakinami(Hokkaido Information University), Masa-yuki Yamamoto(Department of systems engineering, Kochi University of Technology)

2:45 PM - 3:00 PM

[MTT43-05] Three-dimensional large-scale numerical simulation of infrasound associated with tsunami generation considering wave source and atmospheric models

*Yoshiki Saito1, Kan Okubo1, Kentaro Uehara2, Hidee Tatehata2, Hiromu Yokosu3 (1.Tokyo Metropolitan University, 2.Japan Weather Association, 3.Chubu Electric Power Company)

Keywords:infrasound, atmospheric pressure wave, large earthquake, tsunami, numerical simulation, disaster detection

For several decades, pressure changes associated with tsunami generation have been observed in the case of large earthquakes, and the research on this phenomenon has been conducted. Past studies have reported that this change in atmospheric pressure (infrasound) is induced by the generation of a tsunami. Since infrasound propagates at a speed faster than that of a tsunami, it is expected to be applied to early detection of tsunamis. In other words, using infrasound as one of the observation targets for tsunami detection makes it possible to further improve the robustness and stability of tsunami detection. However, for this phenomenon, detailed numerical analysis considering the effects of wave sources and atmospheric environment based on actual physical phenomena has not been sufficiently studied. According to the frequency of tsunami occurrence, it is important to establish a highly reproducible numerical analysis method. Therefore, in this study, we implemented a three-dimensional large-scale propagation numerical analysis considering the wave source and atmospheric model, and numerically examined the infrasound induced by the tsunami. In this numerical experiment, tsunami-induced infrasound was compared and evaluated by removing the background atmospheric pressure trend from the observation results of the 2011 off the Pacific coast of Tohoku Earthquake. Through this research, it was clarified that a waveform close to the infrasound obtained in the field observation can be reproduced by numerical analysis employing the wave source and atmospheric environment models.