Japan Geoscience Union Meeting 2021

Presentation information

[J] Poster

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 5:15 PM - 6:30 PM Ch.20

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)

5:15 PM - 6:30 PM

[MTT43-P02] The Infrasound signals excited by a bolide on 29th November 2020

*Makiko Iwakuni1, Masa-yuki Yamamoto2, Hiroaki Saito3, Islam HAMAMA2, Nobuo Arai4, Takayuki Otsu1, Mami Nogami1, Takahiko Murayama1 (1.Japan Weather Association, 2.Department of systems engineering, Kochi University of Technology, 3.Cosmosciences, Hokkaido University, 4.Disaster Mitigation Research Center, Nagoya University)

Keywords:Infrasound, Meteor, Multiple infrasound stations at short distances (100km), Microbarograph

An infrasound observation system has been installed in Shima region, Mie prefecture since 2015 by Japan Weather Association (JWA). Kochi University of Technology (KUT) started the operation of an infrasound sensor in 2016. Currently, many infrasound sensors are deployed over the Japanese islands (widely from Kyusyu region to Hokkaido region. JWA and KUT collect these infrasound data in real time to monitor natural disasters such as tsunami and volcanic eruption. The collection of infrasound observation system of KUT is named KISONS (Kochi university of technology InfraSound Observation data Network System).



Infrasound sensors of JWA and KUT observed infrasound signals excited by a bolide which flew over off Kii channel around 01:34 on 29th of November 2020 (JST). Many people witnessed this bolide, and optical observation data gave the information that the flying route of it. At the infrasound station closest to the bolide trajectory, Toyo town in northeastern part of Kochi prefecture, the infrasound sensor detected some signals around 01:39. Other two infrasound sensors at Cape Muroto in Kochi prefecture detected signals after 01:39. On Kii peninsula, sensors of KUT in Kumano city and Owase city and sensors of JWA in Shima also detected signals. The direct distance between the height of the vanishing point of the bolide trajectory and each infrasound station, was 86 km at the nearest Toyo town and 196 km at the farthest Shima site (Shima high school). As far as we know, this is rare case to detect signals excited by a bolide at multiple infrasound stations in Japan as close as approximately 100 km distance from the bolide trajectory. It will be a valuable case to study the changes in the signals due to propagation from the bolide trajectory.



We thank SonotaCo Network members. In this group they optically observe bolides, meteors and so on, discuss the orbit. SonotaCo Network URL: http://sonotaco.jp/