With the speed at which tsunami waves travel through open water , no system can protect against a very sudden tsunami , where the coast in question is too close to the epicenter . A devastating tsunami occurred off the coast of Hokkaidō in Japan as a result of an earthquake on July 12 , 1993 . As a result , 202 people on the small island of Okushiri , Hokkaido lost their lives , and hundreds more were missing or injured . This tsunami struck just three to five minutes after the quake , and most victims were caught while fleeing for higher ground and secure places after surviving the earthquake . This was also the case in Aceh , Indonesia
an earthquake on July 12 , 1993
1993 Hokkaidō earthquake
Tsunami warning system