Akio Katsumata1, Yutaka Hayashi1, Kazuki Miyaoka1, Hiroaki Tsushima1, Toshitaka Baba2, Patricio A. Catalán3, Cecilia Zelaya4, Felipe Riquelme Vasquez5, Rodrigo Sanchez-Olavarria6, and Sergio Barrientos61Meteorological Research Institute, Japan Meteorological Agency, Nagamine 1-1, Tsukuba, Ibaraki Prefecture, Japan 2Tokushima University, Shinkura-cho 2-24, Tokushima, Tokushima Prefecture, Japan 3Federico Santa Maria Technical University, Avenida de-España 1680, Valparaíso, Región de Valparaíso, Chile 4Hydrographic and Oceanographic Service, Chilean Navy, Errázuriz Echaurren 254, Playa Ancha, Región Valparaíso, Chile 5National Office of Emergency of the Interior Ministry, Calle Beaucheff 1671, Santiago, Región Metropolitana, Chile 6University of Chile, Av Libertador Bernardo O’Higgins 1058, Santiago, Región Metropolitana, Chile
Received: 12 May 2016 – Accepted for review: 14 Jun 2016 – Discussion started: 21 Jun 2016
Abstract. One of the quickest means of tsunami evacuation is transfer to higher ground soon after strong and long ground-shaking. Strong ground motion means that the source area of the event is close to the current location, and long ground-shaking or large displacement means that the magnitude is large. We investigated the possibility to apply this to tsunami hazard alarm using single-site ground motion observation. Information from the mass media may not be available sometimes due to power failure. Thus, a device that indicates risk of a tsunami without referring to data elsewhere would be helpful to those should evacuate. Since the sensitivity of a low-cost MEMS accelerometer is sufficient for this purpose, tsunami alarms equipment for home use may be easily realized. Several observation values (e.g., strong-motion duration, peak ground displacement) were investigated as candidates. It was found that a suitable value for a single-site tsunami alarm is long-period peak displacement or the product of strong-motion duration and peak displacement. It was possible to detect an earthquake with a magnitude greater than 7.8 with a 0.8 threat score. Application of this method to recent major earthquakes indicated that such equipment could effectively alert people to the possibility of tsunami.
Katsumata, A., Hayashi, Y., Miyaoka, K., Tsushima, H., Baba, T., Catalán, P. A., Zelaya, C., Riquelme Vasquez, F., Sanchez-Olavarria, R., and Barrientos, S.: Stand-Alone Tsunami Alarm Equipment, Nat. Hazards Earth Syst. Sci. Discuss., doi:10.5194/nhess-2016-164, in review, 2016.