The next issue of The Russian Journal of Seismology (Vol. 7, No. 3) has been published. The issue contains articles written by scientists from different regions and research organizations of Russia.

Traditionally, at the beginning of each half-year, our journal publishes a regular article “Global earthquakes in the first half of 2025 according to the GS RAS” (authors: Yu.A. Vinogradov, M.I. Ryzhikova, N.V. Petrova, M.V. Kolomiets), which presents information on the seismicity of the Earth in the first half of 2024 at a magnitude level of mb (MS) ≥ 6.0 (a total of 67 earthquakes), as well as information on 66 earthquakes felt on the territory of the Russian Federation according to the Alert Service of the Geophysical Survey of the Russian Academy of Sciences. It is noted that the seismic energy released on the globe in the first half of 2024 increased compared to that in the second half of 2023, but remained below the average semi-annual value for the period 2010–2023, as in the two previous years.

A pair of authors, Yu.F. Kopnichev (IPE RAS, Moscow) and I.N. Sokolova (GSR AS, Obninsk), who regularly publish in the Russian Seismological Journal, presented their new paper, “Spatio-temporal variations of short-period S waves attenuation field structure in the region of North-Korean Pungeri nuclear test site” which examines spatio-temporal variations in the structure of the shear-wave attenuation field in the area of ​​the North Korean Pungeri nuclear test site. Determining the Lg/Pg parameter in records of underground nuclear explosions revealed a sharp decrease from 2006 to 2017. This effect is believed to be related to the upwelling of deep fluids in the lithosphere, caused by the intense anthropogenic impact of underground nuclear explosions on the Earth's crust.

Our colleagues from the IO RAS, Moscow and Sirius University, Krasnodar region, M.A. Novikov and A.A. Krylov, presented the article “Refinement of seismic regime parameters for the Lena River delta region” This publication reports on the identification of two main seismic lineaments in the Lena River Delta and the determination of their key parameters: recurrence graphs, the position of the seismogenic crustal layer, maximum magnitude, the direction of the principal stress axes in the crust, and the parameters of generalized focal mechanisms. The results can be used for detailed seismic zoning of the Lena River Delta.

The article “Seismicity of the Prikhankai lowland during its flooding” (S.B. Naumov, GS RAS, Vladivostok) examines two phenomena in the Khanka Lowland: the flooding of the southeastern shore of Lake Khanka and the increased frequency of earthquakes in this area. The article also identifies potential causes for the expansion of Lake Khanka and the increased frequency of earthquakes, demonstrating a possible relationship between these natural phenomena.

The next publication, “Relationships between some key segments of the Pacific Plate collision with the Okhotsk Plate in connection with the strongest earthquakes of 1952 and 2025 in southeastern Kamchatka” (A.S. Zakupin, Siberian Branch, GS RAS, Yuzhno-Sakhalinsk), responds to a recent powerful seismic event near Kamchatka. It examines the seismicity of a segment of the Central Sakhalin Fault in southern Sakhalin and adjacent areas of the Sea of ​​Okhotsk in connection with the large earthquakes of 1952 and 2025 in southeastern Kamchatka. It is shown that this segment of the Central Sakhalin Fault interacts with the West Sakhalin and Hokkaido-Sakhalin faults.

A team of authors from the Yakutsk Branch of the GS RAS (R.M. Tuktarov, A.S. Kulyandina, S.V. Shibaev) presented data on the earthquake that occurred on June 28, 2025, in northeastern Yakutia, south of the Dmitry Laptev Strait, in the article “South Anyui earthquake June 28, 2025”. The earthquake's focal point was located at a depth of 10 km, and its magnitude (m_b) was 5.3. Instrumental parameters of the earthquake and data on the tectonic position of the South Anyui Suture are described.

Another team of authors from the Central Branch and Dagestan Branch of the GS RAS (I.P. Gabsatarova, N.L. Ponomareva, M.M. Akhmedova) performed the same study in their article, “Novokayakentskoe-I earthquake on August 26, 2025 in the shelf part of the Caspian Sea with ML=5.6”. Instrumental and macroseismic data are presented. A focal mechanism solution was obtained based on the first arrival signs of P-waves at 95 seismic stations. It was established that the focal point was a nearly pure normal fault along one of the steeply dipping, sublatitudinal-trending nodal planes.