Parametric resonance of surface geomagnetic waves as a precursor of local earthquakes

Earthquake prediction is currently one of the most pressing problems in the Earth sciences, to a large extent one of the main tasks of physics of the Earth and the most important task of seismology. This paper considers the distinctive features of geomagnetic disturbances observed in the structure of geophysical fields during the development of a seismic process. An analysis of observations of the geomagnetic field at various points on the Earth's surface in connection with an earthquake of magnitude 7.8 and 7.5 that occurred in the region of Turkey on February 06, 2023 was carried out. The process of noise suppression without damaging high-frequency information was carried out using the Multivariate Denoising method.

The analysis of bursts, moments of sharp changes in the oscillation mode was carried out using the wavelet transform method of data at various levels. For the first time, it was proposed to consider the parametric resonance of surface geomagnetic oscillations as a precursor of earthquakes. As the moment of the earthquake onset approaches, regions of pronounced topological similarity of geomagmetic field curves for magnetic variation stations in the interval from 5 to 6 h and then in the interval from 25 to 30 min before the earthquake.

Using the wavelet transform method of data at the geomagnetic station in Simeiz, a picture of the restructuring of the frequency of surface geomagnetic oscillations was obtained before the main shock in Turkey.