General Design of Mobile Tsunami Warning System—Performance since 2017 and Future Development

The massive loss of life caused by tsunamis in recent history demonstrates the need for better warning systems that can alert coastal residents effectively for saving lives. Recently, we have been developing a mobile tsunami warning system by augmenting NASA's real-time GNSS (global navigation satellite system) with the global tele-seismic network to detect tsunami scales immediately after an earthquake and alert only those people at risk. The prototype system has three innovative components: (i) automated earthquake inversion using GNSS and seismic data, (ii) real-time determination of tsunami scales for warning levels, and (iii) reliable cloud computing and mobile communication to the public.

Since its in-house operation in 2017, the system has processed 68 large earthquakes globally from magnitude of 5.5 to 8.2. Only five of them, not necessarily those largest ones, were determined as tsunamigenic earthquakes. Validation by after-event data shows clear advantages in determining killer tsunamis, including the 2018 Palu tsunami that killed about 4,340 people, followed the 7.5 magnitude earthquake in Central Sulawesi.