The Koryak strong earthquake of April 20 (21), 2006: Preliminary results

A number of terrain features and objects of the settlements of Tilichiki and Korf and the village of Khailino in the epicentral zone of the strongest earthquake in the north of the Kamchatka region were examined in the first days after the earthquake. Primary and secondary coseismic ruptures were identified on the surface. An outcrop of the seismic source was discovered in the form of an extended seismic fault about 140 km in traceable length. The settlements were inspected for the purpose of elucidating the macroseismic effect, structural maps were compiled, and the main types of ruptures were identified. The network of seismic stations on Kamchatka and in eastern Russia recorded a few thousand aftershocks. The gathered data provide insight into the structure of the source and its tectonic position at the Asian active continental margin.