Presentation Information
[U15-01]Observations for Earthquake and Tsunami Disaster Mitigation over the Past Three Decades★Invited Papers
*Shin Aoi1 (1.National Research Institute for Earth Science and Disaster Resilience)
Keywords:
earthquake observation,tsunami observation,NIED MOWLAS,early warning,observation for disaster mitigation,cable-type seafloor observation network
Japan is exposed to a wide range of natural hazards triggered by various natural phenomena, including earthquakes and tsunamis, volcanic eruptions, typhoons and heavy rainfall, heavy snowfall, tornadoes, and landslides, resulting in at least several tens of fatalities each year. Compared with other hazards, earthquakes and tsunamis less frequently cause events with dozens or more fatalities at once; however, one notable aspect is that, once every 10 to several tens of years, an earthquake occurs that results in catastrophic losses ranging from hundreds to more than ten thousand fatalities.
In Japan, since the Japan Meteorological Agency (JMA) began instrumental seismic observations with seismometers more than 150 years ago, seismic monitoring has been actively advanced by various organizations. The current nationwide observation networks were established in response to lessons learned from two major disasters, particularly the 1995 Kobe earthquake and the 2011 Tohoku earthquake.
At the National Research Institute for Earth Science and Disaster Resilience (NIED), eight networks are integrated and jointly operated as NIED observation network for earthquake, tsunami, and volcano (MOWLAS): four foundational land-based observation networks (Hi-net, F-net, K-NET, and KiK-net), three foundational offshore observation networks (S-net, DONET, and N-net), and the foundational volcano network (V-net). MOWLAS, which consists of more than 2,200 stations, is among the world’s highest-level observation systems in terms of station number and density, reliability, and data quality. A major distinguishing feature is that it includes not only dense land coverage but also spatially distributed networks of seismometers and tsunami sensors (ocean-bottom pressure gauges) in offshore regions. Offshore observation is an extension of monitoring into the areas where people are not living and, by enabling measurements closer to the sources of offshore earthquakes, provides a major disaster-mitigation advantage by allowing earlier detection.
MOWLAS data are openly available through the internet and have made significant contributions to research and development, while also being widely utilized for disaster risk reduction. The observation data are transmitted in real time to JMA. MOWLAS data support the issuance of earthquake early warnings, tsunami warnings, and seismic intensity information, thereby contributing to the mitigation of ongoing disasters. The data are also used in earthquake engineering, including input ground motions for structural design, contributing to the reduction of physical damage. In addition, these observations play a major role in improving the accuracy of earthquake and tsunami hazard assessments.
This presentation reviews the development of earthquake and tsunami observation in Japan since the 1995 Kobe earthquake and discusses how these data have been applied to practical measures to reduce disaster impacts.
In Japan, since the Japan Meteorological Agency (JMA) began instrumental seismic observations with seismometers more than 150 years ago, seismic monitoring has been actively advanced by various organizations. The current nationwide observation networks were established in response to lessons learned from two major disasters, particularly the 1995 Kobe earthquake and the 2011 Tohoku earthquake.
At the National Research Institute for Earth Science and Disaster Resilience (NIED), eight networks are integrated and jointly operated as NIED observation network for earthquake, tsunami, and volcano (MOWLAS): four foundational land-based observation networks (Hi-net, F-net, K-NET, and KiK-net), three foundational offshore observation networks (S-net, DONET, and N-net), and the foundational volcano network (V-net). MOWLAS, which consists of more than 2,200 stations, is among the world’s highest-level observation systems in terms of station number and density, reliability, and data quality. A major distinguishing feature is that it includes not only dense land coverage but also spatially distributed networks of seismometers and tsunami sensors (ocean-bottom pressure gauges) in offshore regions. Offshore observation is an extension of monitoring into the areas where people are not living and, by enabling measurements closer to the sources of offshore earthquakes, provides a major disaster-mitigation advantage by allowing earlier detection.
MOWLAS data are openly available through the internet and have made significant contributions to research and development, while also being widely utilized for disaster risk reduction. The observation data are transmitted in real time to JMA. MOWLAS data support the issuance of earthquake early warnings, tsunami warnings, and seismic intensity information, thereby contributing to the mitigation of ongoing disasters. The data are also used in earthquake engineering, including input ground motions for structural design, contributing to the reduction of physical damage. In addition, these observations play a major role in improving the accuracy of earthquake and tsunami hazard assessments.
This presentation reviews the development of earthquake and tsunami observation in Japan since the 1995 Kobe earthquake and discusses how these data have been applied to practical measures to reduce disaster impacts.