Development of Earthquake Early Warning System Using Ocean Bottom Seismographs 

JR East has introduced an Earthquake Early Warning System for Shinkansen Lines, with seismographs installed along its Shinkansen lines and in coastal and inland locations to detect earthquakes early and trigger an emergency stop of Shinkansen services. Coastal seismographs detected the Great East Japan Earthquake in 2011 before the effects were felt on land, helping us to stop our Shinkansen services safely.

National Research Institute for Earth Science and Disaster Resilience (NIED) began using ocean bottom seismographs to monitor earthquakes along the Japan Trench, which extends from Chiba-oki to Hokkaido-oki, in 2016. If the data from these ocean bottom seismographs can be used for early detection of earthquakes, this will make it possible to detect future earthquakes like the Great East Japan Earthquake in the Pacific Ocean before they reach our Shinkansen Lines, making it possible to stop our Shinkansen services earlier. We therefore developed earthquake early warning using data from ocean bottom seismographs. Based on the results of our development, JR East began utilizing ocean bottom seismograph data from Boso-oki (S1) in November 2017, and data covering the area from Ibaraki-oki to Kushiro-oki (S2-S5) in January 2019 for our Earthquake Early Warning System for Shinkansen Lines. We are currently researching method to utilize data from the seismographs for earthquake early warning on conventional lines.