Bogdanov V.V., Pavlov A.V. \\ Solar-terrestrial relations and physics of earthquake precursors: XII International Conference, Paratunka village, Kamchatka Krai, September 27 – October 01, 2021. collection of tez. dokl. – Paratunka: IKIR FEB RAS, 2021. p.77.

Identification of ionospheric precursors of earthquakes in Kamchatka region based on correlation analysis

 Seismic activity is one of the sources of ionospheric variability. In this work, based on the methodology [Pulinets et al, 2004], the electron concentration change in the ionosphere preceding the onsets of strong earthquakes with M ≥ 6.0 in Kamchatka region was investigated. This technique is based on calculating the correlation coefficient between the values of the critical frequency foF2 of two ionospheric stations, one of which is located inside the earthquake preparation zone, and the other is outside. If the observation points are located in similar geographical conditions, then the same ionospheric variations will also be observed under both calm and disturbed geomagnetic conditions, except for those points that are located in the seismically active zone. Local anomalies in the F2 layer accompanying the preparation of strong earthquakes should manifest themselves in a decrease in the mutual correlation of foF2critical frequencies between stations located inside and outside the seismic zone. The data obtained at two stations PETROPAVLOVSK (PK553) and EARECKSON (EA653) for the period 01.09.2018–30.04.2021 are considered. The PK553 station with coordinates (52.97∘ S, 158.24∘ V) was located in Kamchatka in the seismic event preparation zone, and the EA653 station (52.73∘ S, 185.92∘ V) was considered as a control station. Statistical analysis of the foF2 critical frequencies showed that for 7 out of 14 earthquakes with M ≥ 6.0, which occurred at depths up to 100 km and epicentral distances up to 500 km from the location of PK553, a noticeable decrease in the correlation coefficient occurred 1-7 days before. The work was carried out within the framework of implementation of the State Task AAAA-A21-121011290003-0.