UrEDAS-the early warning system for mitigation of disasters caused by earthquakes and tsunami

Jun Saita, Yutaka Nakamura
System and Data Research Co., Ltd., SDR Bldg. 3-25-3 Fujimidai Kunitachi-shi, Tokyo 186-0003, Japan.
Tel. : +81-2-574 4536, Fax: +81-2-574 4576
E-mail: yutaka@sdr.co.jp

An earthquake is a devastating natural disaster that can cause a large number of casualties and extensive damage in a few minutes. UrEDAS (Urgent Earthquake Detection and Alarm System) is an intelligent and unique alarm system which includes three component seismometers. This is a single station system that does not need any extra organisation for networking. Immediately after the arrival of the P-wave, it gives information on the magnitude, location and depth of the earthquake within four seconds. Then the damage estimation is made on the basis of the calculated magnitude, epicentral distance and depth. Using a similar approach, by relating the hypocentral depth, magnitude and the distance between the offshore point and the coastal line, the estimation of the damage potential of a tsunami is also possible. By quickly estimating the earthquake parameters, the alarm can be issued within a few seconds for the areas that are vulnerable to earthquakes and tsunamis. It is needless to say that to be able to effectively use this approach, together with the early alarming, it is also necessary to educate and prepare people to follow disasters reduction procedures in big and destructive earthquakes.