Ультранизкочастотные Флуктуации Геомагнитного Поля По Измерениям На Обсерватории Алма-ата [43.25n; 76.95e]
Year: 2023
Type: article
Abstract: The variability of the geomagnetic field in seismic regions is the subject of close at-tention of geophysicists. Work in this direction is carried out in order to identify geomagnetic data perturbations of space and lithospheric nature. This paper presents the results of a study of the be-havior of the magnetic field in the seismic region of the Northern Tien Shan on the basis of data from the Observatory "Alma-Ata" [43.25N; 76.95E]. The distinctive features of ultra-low-frequency fluctuations in the magnetically disturbed day (Kp=8) and in the magnetically calm day (Kp=2) were established. On the perturbed day, the oscillation amplitude is 5-15 NT with periods from 2 to 5 minutes, whereas on the magnetically calm day the oscillation amplitude is the largest in the Z-component, they are 0.50.15 NT with periods less than 1 min. The dynamics of the spectral index β calculated by the method of fast Fourier transform for the midnight values of the geomag-netic field in the seismic period is studied. It was found that the dynamics of the spectral index β is determined by the geomagnetic environment, that is, external factors such as solar flare activity, primarily affect the characteristics of ultra-low-frequency fluctuations of the geomagnetic field. The presence of seismogenic anomalies is not observed, possibly due to the average intensity of earth-quakes.
Language: Russian
Subfield: Geophysics
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W7219986290