[M-TT45] Brand-new scope of coupling geophysics being established by infrasound and associated waves

[MTT45-02] Propagation of atmospheric pressure fluctuation observed at the IMS of CTBT during the eruption of Hunga Tonga-Hunga Ha'apai volcano

*Masashi Motohashi¹, Nobuo Arai², Takayuki Otsu¹, Takanari Fujii¹, Makiko Iwakuni¹, Mami Nogami¹ (1.Japan Weather Association, 2.Disaster Mitigation Research Center, Nagoya University)

Keywords:infrasound, CTBT, waveform analysis, volcano eruption

Japan Weather Association (JWA) is working as the Comprehensive Nuclear-Test-Ban Treaty (CTBT) National Data Centre-1 (NDC-1) of Japan which is in charge of analysis on waveform data, operation and maintenance of seismic and infrasound stations in Japan. We observed atmospheric pressure fluctuation from large tsunami at the time of 2011 off the Pacific coast of Tohoku Earthquake. If the signals from such hazardous phenomena can be detected immediately, it will be very helpful to alert the occurrence of disaster or approach of hazardous phenomena. This triggered us to build our own observation network in Japan. We are challenging to utilize the infrasound technologies for civil and science application as well as nuclear test monitoring.
On January 15th, 2022, a major eruption of the underwater volcano Hunga Tonga-Hunga Ha'apai occurred off the coast of Tonga. As a result of this eruption, atomospheric pressure fluctuations were observed at all of the CTBT IMS infrasound stations. Moreover, it was captured that the pressure fluctuation excited by the eruption traveled around the earth at least twice. In this paper, we discuss how the waveform and amplitude of the pressure fluctuation change with the propagation.