ONOR EARTHQUAKE on August 14, 2016, Mw=5.8 (Sakhalin Island)

Abstract

On August 14, 2016 at 11h15m UTS there was a strong earthquake with Mw=5.8 in the central part of the Sakhalin Island, which felt in nearby settlements with an intensity of up to Ii=5–6 by the MSK-64 scale. The greatest intensity of shaking was recorded in the village of Onor, closest to the epicenter. Within 2 weeks after the earthquake, more than 130 aftershocks were registered by regional seismic stations. The aftershock zone is extended in the NW-SE direction. Subhorizontal compressional stresses of the NE-SW orientation were realized in the earthquake foci. The type of movement in the source is a reverse-fault with a slight strike-slip component. The fault plane with the south-western dip direction was adopted as an operational. The earthquake source belongs to one of the secondary structures of the Central Sakhalin oblique-reverse fault, which cuts through a section of the Western Sakhalin Mountains in the direction of the western coast. The active block of the fault is the eastern wing, underthrusting under the western one. Based on the results of the macroseismic inspection, theoretical isoseists are calculated and constructed. Such a rare strong earthquake aroused wide interest among specialists and allowed them to test several new methods and technical solutions, as well as obtain new information about the seismicity and tectonics of the Sakhalin region. This article presents a comprehensive overview of seismological information on this earthquake, mainly based on the results of earlier publications.