Japan Geoscience Union Meeting 2019

Presentation information

[J] Oral

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

[M-TT49] Brand-new scope of coupling geophysics being established by infrasound and associated waves

Thu. May 30, 2019 10:45 AM - 12:15 PM 202 (2F)

convener:Masa-yuki Yamamoto(Department of systems engineering, Kochi University of Technology), Mie Ichihara(Earthquake Research Institute, University of Tokyo), Nobuo Arai(Disaster Mitigation Research Center, Nagoya University), Chairperson:Masa-yuki Yamamoto(Kochi University of Technology), Hiroaki Saito(Kochi University of Technology)

11:30 AM - 11:45 AM

[MTT49-04] Comparison of seismic waveforms observed by co-located seismometer and barometer installed indoors 2nd report

*Makiko Iwakuni1, Nobuo Arai2, Takayuki Otsu1, Masashi Motohashi1, Toyomi Sakamoto1, Takanari Fujii1, Ryohei Emura1, Mami Nogami1, Takahiko Murayama1, Takuma Oi3 (1.Japan Weather Association, 2.Disaster Mitigation Research Center, Nagoya University, 3.Toho Mercantile co., Ltd.)

Keywords:Barometer, Seismometer, Barometer's Internal Mechanical Response by Earthquake

Surface vertical vibration due to earthquake is considered to excite sound, and it has been observed by barometer or microphone. Recorded pressure change response to seismic ground motion is considered to be due to difference of gravitational pressure observed by barograph moving up and down, air vibration (compressional wave) excited by earthquake ground motion around barograph, and internal mechanical response to acceleration by earthquake.

We started observation with co-located seismometer and barometer in Isumi, Chiba-prefecture (I30JP in The IMS Infrasound Network of CTBTO). This time one of barometer's port is close. A magnitude 4.5 earthquake occurred off south of Chiba-prefecture at a depth 44km. The seismic intensity scale in Isumi was 2. The port open barometer recorded pressure change due to the earthquake. Whereas, the port close barometer did not record pressure change due to the earthquake. It seems that the gravitational pressure change and barometer's internal mechanical response is very little at the seismic intensity 2 earthquake.