On the Occurrence of Typical Precursory Anomalies in the Foreshock Areas of Some Large Earthquakes, Kuril–Kamchatka Region

Abstract

This paper discusses the potential of a new algorithm for earthquake prediction based on a set of precursory anomalies that have been previously identified reliably by construction and analysis of the generalized vicinity of a large earthquake. The differences between physical mechanisms generating earthquakes at different depths have been taken into account. We use data from the regional catalog for Kamchatka and the North Kuril Islands compiled by the KB FRC UGS RAS to discuss the question of how frequently such typical average anomalies are statistically reliably identified in the foreshock areas of individual large earthquakes. For this catalog at least one typical anomaly has been identified in the third of all cases where target М6.5+ earthquakes are concerned. The likelihood of successful retrospective prediction is critically dependent on the number of events recorded in the foreshock area of the large earthquake in question. The increase in the fraction of retrospectively predicted earthquakes with increasing number of events in the foreshock area of a large earthquake is supported by an analysis of data from worldwide ISC-GEM and GCMT catalogs and the double Turkish earthquakes of 2023. Options are suggested to further develop this prediction method, and attention is drawn to the problem of false alarms.