The next issue of The Russian Journal of Seismology (Vol. 6, No. 2) has been published. The issue contains articles written by authors from various institutions in several regions of Russia, as well as from Kazakhstan.

The first in the issue is a large article by a team of authors from the Kamchatka branch of GS RAS “Integrated geophysical observations and information resources of the Kamchatka Branch of the Geophysical Survey of the Russian Academy of Sciences (Kamchatka Peninsula)” (authors: D.V. Chebrov, G.N. Kopylova, V.A. Kasimova, E.O. Makarov), which presents a description of the types of observations and information resources of the Kamchatka branch of the GS RAS. These resources can be used by scientific and educational organizations of the Russian Federation to study precursors and develop methods for predicting earthquakes and volcanic eruptions, solving a wide range of research problems in the field of geophysical monitoring of seismically active areas and other tasks.

Our colleagues from Kazakhstan A.S. Mukambayev, N.N. Mikhailova, V.I. Dubrovin presented the publication “On Monitoring of mining explosions conducted on the territory of the former Semipalatinsk Test Site”. This article talks about the experience of recording signals from explosions at several mineral deposits within the territory of the former Semipalatinsk test site by stations of the IGR NNC RK network. Recommendations were made regarding processing for analysts at the Kazakhstan National Data Centre.

Scientists from the IPE RASa and the GS RAS Yu.F. Kopnichev and I.N. Sokolova also turned their attention to the East of our country and reported on their study “Ring-shaped seismicity structures in the region of Kamchatka: possible preparation for great earthquake”, according to which a strong event with a possible magnitude of Mw = 8.6 ± 0.2 is being prepared in the area under consideration. They were able to come to this conclusion based on the results of a study of some characteristics of seismicity in the Kamchatka Peninsula area. It was established that before two recent strong earthquakes, pairs of ring structures of seismicity were formed here at depths of 0–33 and 34–70 km. Particular attention is paid to the region located between 52 and 54° N, the lithosphere of which is characterized by an anomalously high absorption of short-period shear waves.

A large team of authors from the FSUE “VNIIA” and the GS RAS (A.Yu. Eltekov, O.A. Gerasimchuk, P.M. Utkin, Yu.A. Vinogradov) demonstrated in the article “Researches and measurements of high-sensitive seismometers at experimental base «Obninsk»” the results of studies and measurements of the characteristics of self-noise and nonlinear distortions of highly sensitive broadband and short-period seismic receivers, carried out at the experimental base “Obninsk” of the Geophysical Survey of RAS. The article states that thanks to the stable temperature in the gallery and modernized measurement techniques, it is possible to obtain fairly accurate estimates of the characteristics of highly sensitive geophones. It is argued that the Obninsk experimental base serves as one of the possible locations for conducting studies of the characteristics and technical control of modern seismic instruments.

Seismologists from Obninsk A.S. Zvereva, A.I. Klianchin (GS RAS) presented a selection of instrumental and macroseismic data on the earthquake on January 24, 2024 at 11:19 with Mw=4.1, h=8 km with an epicenter 30 km from Krasnodar in the article “Earthquake on January 24, 2024 near Krasnodar city, Mw=4.1, I₀=5”. Source spectra were calculated from records of three regional seismic stations. The spectral parameters of the focus were determined. A solution to the source mechanism was obtained based on the signs of the first arrival of P-waves at 71 seismic stations. The maximum intensity at the epicenter was I=V MSK-64.

The issue ends with the article “Focus zone model and depth determination based on amplitudes of pP phases” (authors: A.G. Epifansky, L.G. Dulentsova), which showed that under certain conditions, seismic waves generated at different depths for each epicentral distances are projected to one point on the seismic record axis. That is, one pulse of the first arrival can correspond to several depths. Hence the fundamental difficulty of determining the depth solely from the first arrivals – phases P. The solution to the problem is the automatic determination of the times of arrivals of deep phases pP. The algorithm developed by the authors uses all records simultaneously in calculations. As a result, the difficulties associated with determining the depth of a crustal tectonic seismic event will be reduced.