PHYSICS

Estimation of the prognostic efficiency of ionospheric disturbances preceding the occurrence of earthquakes with a magnitude of $M\ge 5.0$ in the Kamchatka region

A. V. Pavlov

Institute of Cosmophysical Researches and Radio Wave Propagation, Far East Division, Russian Academy of Sciences

Abstract: Anomalous changes in the parameters characterizing the state of the ionospheric E and F regions observed before the onset of seismic events can be considered as possible ionospheric precursors of these earthquakes. In order to identify seismoionospheric disturbances preceding the onset of earthquakes, the work used hourly values of the h$^\prime$Es, hmF2, fbEs, fbEs and foF2 parameters, which were obtained for the period 2016–2023 at the ionospheric station of vertical radio sounding located in the village of Paratunka (52.97$^\circ$ N, 158.24$^\circ$ E). Deviations of the values of the ionospheric parameter complex from the upper limit of the range of their background values during the daily interval in the absence of geomagnetic disturbances were considered as a possible ionospheric precursor of earthquakes. The methods of A.A. Gusev, G.M. Molchan, the Hansen-Kuiper criterion, and the reliability and validity of the precursor were used to estimate the prognostic efficiency. The prognostic efficiency was estimated for earthquakes that occurred in the time interval 2016-2023, with magnitudes M$\ge$ 5.0, M$\ge$ 5.5, M$\ge$ 6.0, hypocenter depths of up to 100 km and epicentral distances of up to 400 km to the location of the ionospheric station. According to the obtained estimates of the prognostic efficiency of the complex of ionospheric parameters under consideration, the forecast of seismic events with magnitudes M$\ge$ 5.0 and M$\ge$ 5.5 differs from random guessing and, therefore, the identified ionospheric disturbances can be associated with the processes of earthquake preparation. The highest values of the forecast efficiency were obtained for earthquakes with magnitudes M$\ge$ 5.5.

Keywords: ionosphere, vertical radio sounding, lithosphere, earthquake, earthquake precursor.

UDC: 554.510.535

MSC: Primary 86A10; Secondary 86A15

Received: 16.10.2024
Accepted: 18.11.2024

DOI: 10.26117/2079-6641-2024-49-4-203-219