New Data on the Parameters of Historical Tsunami and Geological Traces of Coseismic Subsidences on the Coast of Khalaktyrsky Beach (Avacha Bay, Kamchatka)

Abstract

This article presents the results of detailed mapping of the deposits of the strongest historical tsunamis of 1923 and 1952 on the coast of the Khalaktirskiy Beach of the Avacha Bay (Kamchatka Peninsula). A new approach is proposed in the search for buried erosion scarp of marine accumulative terraces, which are geological traces of abrupt coseismic subsidence. Using this approach, a successful search was made for a buried scarp formed during a strong subduction earthquake at the beginning of the Late Holocene. This work is part of the ongoing paleoseismological studies of earthquakes and tsunamis in the Kuril-Kamchatka subduction zone.