The on-site earthquake warning system is especially effective for use in places close to the epicenter, which is a weak point of the EEW. Taiwan is leading the research and development of this system, so I read through the papers written by Taiwanese researchers in English. In Taiwan, however, there are many earthquakes with shallow epicenters, and most of the research was conducted while assuming that. Meanwhile, in Japan, the epicenters of many earthquakes are deep, like the 2001 Geiyo Earthquake and the 2009 Suruga Bay Earthquake. Since there is almost no research about on-site earthquake warnings for intermediate depth earthquakes, I selected this theme.

　Data was analyzed based on the observational data of past earthquakes published on the Internet. The value (τc) indicating the magnitude of an earthquake and the values (Pd) indicating the distance from the observation point were calculated using the vertical waveforms of the observation points, whose distance from the epicenter is less than 30 km, and compared them with four other earthquakes with the same magnitude and scale.
　Although the intermediate depth earthquakes shake strongly enough to issue an alarm, the Pd values were small, so they were judged as not necessary to issue an alarm. This means there is a risk of overlooking dangers. In Japan and other countries where intermediate depth earthquakes often happen, we need other evaluation indices instead of Pd so as not to underestimate the damage that may be caused by earthquakes.