Observing the phenomenon of coastal If the sea water level has been reduced. After the earthquake, the tsunami may occur is assumed. Let the exodus into the high security.
Observation of the coast If the sea water level has reduced much. After the earthquake, is presumed to be caused by the tsunami. Up to evacuate to higher safety.
Observe the phenomenon of the coast. If the sea had to reduce the water level down. After the earthquake to assume potential tsunami followed. To migrate up to higher safety.