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The establishment of the tsunami warning system is based on the fact, that the seismic waves propagate faster then tsunami wave. The tsunami wave arrive in the shore line after the earthquake parameters can be determined, so that there is time left to evaluate the earthquake, whether the earthquake is tsunamigenic or not, disseminated the information or warning to the target area, and finally to do evacuation if necessary. For the tele-tsunami, in which the tsunami will arrive in the beach more then one hour after the origin time of earthquake, generally there is enough time to do all of those processes, so that the warning can be disseminate in 100 % confidence level. For local tsunami, in which the tsunami will arrive in the beach less then one hour, the warning is disseminated in the lower the confidence level. For example, Indonesia Tsunami Warning System (InaTEWS) is designed for local tsunami warning for Indonesian region. Any tsunami-genic earthquake occurs in the Indian Ocean plate boundary, the tsunami wave will sweep the closest shore line within 20-40 minutes after the origin time of the earthquake. The warning is determined just only based on the evaluation of the earthquake parameters and tsunami modeling. It is difficult to add sea level data to increase the confidence level of he warning. Although the confidence level is lower, the tsunami warning could be disseminated. In some cases, especially for the eastern of Indonesia, the tsunami can be generated within inner sea, such as Flores sea, Banda sea, Ceram sea, Maluku sea, and any others. In that cases, tsunami wave will reach the closest shore line within 10 minutes or less. This tsunami may be called as very local tsunami. By evaluating the time line for issuing the tsunami warning, it is clear that very critical to disseminate tsunami warning based on the available technology recently. The effectiveness of the warning is very small, therefore another possibility warning for very local tsunami should be designed. In this presentation, we propose to use natural signs as the warning. As we might know that in general tsunami can be generated by large earthquake.

This kind earthquake could be felt strongly by most peoples. This natural sign could be applied as a tsunami warning. The other possibility is to use rather simple technology, as compliment to the natural warning. A very local tsunami warning system can be designed as the following. The warning system consist of two devices, those are a three component broadband seismograph and a local siren. The seismograph can be used to monitor and estimate the magnitude of the local earthquake and the siren can be used to warn the people if the earthquake is possible to generate tsunami.
Although, the natural signs and the simple technology could be combine to establish the very local tsunami warning system, the important is to educate people so that they understand the earthquake,tsunami, and how they can save from those disasters