Methodology for estimating the probability of strong earthquake occurrence by a complex of seismological and ionospheric precursors

In this paper, based on the combination of medium- and short-term precursors accompanying earthquake generation, a methodology to assess the area, time period and probability of occurrence of strong earthquakes with Ks≥13.5 (M≥6.0) in Kamchatka region is presented. As a medium-term precursor, a seismological prognostic parameter is considered. It is obtained on the basis of a probabilistic model of seismic regime and determines statistically significant deviations of the current probabilities of seismic events with an energy class Ks≥9.0 to occur in the elementary regions, into which the studied seismically active area is divided, from long-term (background) probability values. The waiting area of earthquakes with Ks≥13.5 was defined as a group of areas, in which anomalies of the seismic regime were identified by the  seismological parameter. A complex of ionospheric parameters is considered as short-term prognostic signs with an earthquake waiting period of up to 5 days, they are: the K-layer, the sporadic Es layer of type r, the critical frequency foF2 and the stratification of the F2 layer by frequency. Based on the Bayesian approach, prognostic estimates were made of the occurrence probabilities of strong earthquakes with Ks≥13.5 (M≥6.0) that occurred during the period 2019-2021 in Kamchatka region in the waiting areas determined by the seismological parameter, provided that a complex of anomalous ionospheric parameters was identified.

Bogdanov V.V., Pavlov A.V. \\ Proceedings of the Eighth All-Russian Scientific and Technical Conference with international participation. Petropavlovsk-Kamchatsky. September 26–October 2, 2021 / Ed. by D.V. Chebrov. – Petropavlovsk-Kamchatsky: KF FITZ EGSRAN, 2021. pp. 157-161.