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Development and Research Support for Disaster Prevention and Mitigation, through “Infrasound*” Observation and Analysis Techniques
*Atmospheric Pressure Waves with a Frequency below the Lower Limit of Human Audibility

Natural phenomena, such as seismic ground shaking, generation of tsunami, explosive volcanic eruptions, lightnings, tornadoes, avalanches and landslides, can cause changes and fluctuations in atmospheric pressure (infrasound waves). Infrasound waves may encapsulate the characteristics of the phenomena themselves and propagate over long distances. Therefore, by precisely observing these changes, it may be possible to gain new knowledge, for example, elucidating previously unknown characteristics of the phenomena and the mechanisms of their occurrence.

Japan Weather Association (JWA) is engaged in developing the observation and analysis techniques, as well as establishing a nationwide network of precise atmospheric pressure observations, in order to obtain valuable information for disaster prevention and mitigation from infrasound waves. In addition, to support the customers aiming to improve the disaster prevention and mitigation measures, we conduct comprehensive surveys and research utilizing our expertise and know-how on infrasound waves. This includes the construction of observation systems for infrasound waves, implementation of observations, analysis of observation data, and investigations and research to elucidate various phenomena.

Features

  • We support the elucidation of various phenomena from new perspectives utilizing the infrasound observation and analysis techniques, and the development of technologies and research for disaster prevention and mitigation by integrating with the existing technologies.
Figure 1: Example of a Device for the Infrasound Observation (Quartz Crystal Resonator)
Figure 1: Example of a Device for the Infrasound Observation
(Quartz Crystal Resonator)
Figure 2: On March 11, 2011, atmospheric pressure waves, also known as atmospheric boundary waves, generated in the tsunami source area of Tohoku - Pacific Ocean Earthquake in conjunction with changes in sea level. The atmospheric pressure waves propagated as far as 10,000 km away. At the Mizusawa Observatory, about 210 km from the outset, the NAOJ (National Astronomical Observatory of Japan) detected these atmospheric pressure waves, propagating at nearly the speed of sound, about 12 minutes before the actual tsunami reached the coast.
Figure 2: On March 11, 2011, atmospheric pressure waves, also known as atmospheric boundary waves, generated in the tsunami source area of Tohoku - Pacific Ocean Earthquake in conjunction with changes in sea level. The atmospheric pressure waves propagated as far as 10,000 km away. At the Mizusawa Observatory, about 210 km from the outset, the NAOJ (National Astronomical Observatory of Japan) detected these atmospheric pressure waves, propagating at nearly the speed of sound, about 12 minutes before the actual tsunami reached the coast.
Figure 3. Example of Infrasound Waveform during the Lightning in the Kanto Region on August 29, 2008
Figure 3. Example of Infrasound Waveform during the Lightning in the Kanto Region on August 29, 2008
Figure 4. The Example of Collapsed Area of Snow Avalanche and the Infrasound Wave Excited by the Snow Avalanche Quoted from Arai et al. (2013), the documents prepared for the Committee on Noise and Vibration Research of the Acoustical Society of Japan.
Figure 4. The Example of Collapsed Area of Snow Avalanche and the Infrasound Wave Excited by the Snow Avalanche
Quoted from Arai et al. (2013), the documents prepared for the Committee on Noise and Vibration Research of the Acoustical Society of Japan.

●Observed infrasound data is available.

〇Data name: Observed infrasound data

〇Observation points :
・Iwate Prefecture: Ofunato Junior High School, Massaki Junior High School, Ryori Junior High School
・Mie Prefecture: Minami-Ise High School Nansei Campus, Shima High School, Fisheries High School
・Toyohashi City, Aichi Prefecture: Saigo Elementary School, Suse Elementary School, Tamagawa Elementary School
・The Institute of Statistical Mathematics/Earthquake Research Institute, The University of Tokyo: Shionomisaki, Sugadaira
・National Institute of Information and Communications Technology (NICT): Resilient ICT Research Center, Tohoku University Aobayama Campus, Onagawa Town MASKAR, National Institute of Technology Sendai College Natori Campus, Bansei Onsen, Hokkaido Spaceport, Asahi Gyoseiku Kaikan
・Kochi University of Technology (KUT): Aki-city Fire and Disaster Prevention Center

〇Screen image

Top page of the download page for Infrasound observation data
Top page of the download page for Infrasound observation data
Example of Infrasound Data
Example of Infrasound Data

〇Data usage fee : Free

〇Period of observed data: Past 2 years*1

〇How to view observed data : the link below provides graphs for viewing the data: http://micos-sc.jwa.or.jp/infrasound-net/

〇How to download observed data :

1)Click on the link below to register as a user.
http://micos-sc.jwa.or.jp/infrasound-net/
2)Use the user ID and password sent to your registered email address to log in to the member site, and download the files.

〇Name of the organization from which the observed data originated :
Japan Weather Association
Inter-University Research Institute Corporation, Research Organization of Information and Systems, the Institute of Statistical Mathematics
Earthquake Research Institute, the University of Tokyo
National Institute of Information and Communications Technology (NICT)
Kochi University of Technology (KUT)

〇Format of data file : WIN format*2, CSV format

〇Regarding the use of data: When creating documents using infrasound data, please include the names of all data source organizations in the deliverables and send the deliverables to JWA.

*1 This is past observation data, but it is near real-time.
*2 WIN format：The data format used in the WIN system developed by the Earthquake Research Institute at the University of Tokyo. For more information, see https://www.eic.eri.u-tokyo.ac.jp/WIN/

Applications

  • Study on improving railway facility maintenance and operations management technology
  • Study on improving road maintenance and management techniques
  • Study on improving avalanche monitoring techniques
  • Study on improving landslide monitoring techniques
  • Study on improving lightning and tornado monitoring technology

Related news

  • Infrasound Monitoring Network showed atmospheric pressure changes associated with a major eruption of the Hunga-Tonga-Hunga Ha’apai volcano near the Tonga Islands.
    (Press Release on January 17, 2022)
    https://www.jwa.or.jp/news/2022/01/15589/
  • New observation points in Hokkaido are added in the Infrasound Monitoring Network, and the data is now available. (Announcement from Japan Weather Association on November 08, 2024)
    https://www.jwa.or.jp/news/2024/11/24261/

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