Prehistoric tsunamis and large earthquakes on the Kamchatskiy Peninsula, Kamchatka, based on tephrochronological data

Abstract

For the first time in Kamchatka, tephrochronology has been used to date paleoseismo-dislocations, tsunami deposits, and episodes of seismotectonic uplift that had occurred on the Kamchatskiy Peninsula for the past 2000 years. Four tephra markers have been used: three of the 1964, ~1260, and ~650 A.D. eruptions at Shiveluch Volcano and one of the ~250 A.D. caldera-forming eruption at Ksudach. The deposits of two 13th century and one 7th century tsunamis have been identified and dated. It has been found that Cape Kamchatskiy and Afrika were formed by two large seismotectonic landslides at the beginning of the Christian Era, simultaneously with an uplift of at least 35-40-km of the southeastern coast between the two capes.