THE 1994 SHIKOTAN EARTHQUAKE TSUNAMIS

The 1994 Shikotan earthquake was one of the greatest earthquakes in recent years with a magnitude of M(s) 8.0. A tsunami survey was conducted by Russian and U.S. geophysicists from October 16-30, 1994, less than two weeks after the earthquake. The survey results and a numerical hindcast simulation are reported. Tsunami focusing effect at locations supposedly sheltered by the island chain is discussed. Based on the obtained data, tsunamis which attacked Shikotan Island are characterized as long waves (the order of 10-20 min wave period) with a positive leading wave. Possible consequences of the positive leading wave form are discussed in relation to the observed minimal destruction of beach vegetation and relatively small transport of marine sediment onto the shore. The high-quality tide-gage record in Malokurilskaya Bay indicates the occurrence of a 53 cm subsidence at the site.