This paper presents the results of a study on azimuthal anisotropy in the Earth's mantle based on SKS wave splitting data in the vicinity of the Taupo supervolcano (New Zealand). Using teleseismic data from a local station network for 2003–2018, and using a semi-automated quality control system during parameter selection, a reliable catalog of seismic events was compiled. Detailed analysis of the catalog revealed that the polarization direction of the "fast" shear wave is predominantly oriented along the subduction zone boundary. The delay time between the "fast" and "slow" split waves reaches approximately 1.7 seconds, indicating a significant anisotropy in the mantle layers beneath the station network.
A velocity model of the lithosphere of Central Asia within the Indo-Eurasian collision zone down to a depth of 410 km is presented. The model was obtained by radial ray tracing using data from the International Seismological Centre. This method was applied for the first time to study the folded regions of the Tien Shan, Pamir, and Himalayas and makes it possible to identify medium anomalies from variations in seismic-wave travel times. Optimization of the model using the directional matching method ensured P-wave travel-time residuals of less than 1 second.
This paper provides a relatively simple semi-analytical method for 2D wave equation half-space layer Neumann-type problem solution over an unlimited range of temporal frequencies. It is shown that by representing the traction analog as a Fourier integral and solving the Klein–Gordon equation, a relatively simple alternative to the Cagniard method can be obtained. It is also shown that this method can reduce the solution to the Lamb problem to the sum of three one-dimensional integrals of a real functions. The presented algorithm can be used to solve inverse problems, especially in the diffraction domain, as well as for solving shallow seismic exploration problems and refining the structure of the upper part of the section.
An adaptive automatic algorithm for surface-wave dispersion curve extraction AACPDC (Automatic Adaptive Clustering Picking Dispersion Curves) was developed for the MASW method. The algorithm combines spectralimage thresholding, DBSCAN clustering, curve reconstruction in low signal-to-noise ratio regions, and outlier correction. Spectral analysis is performed using the noise-resistant SFK method. The algorithm was validated on synthetic data, engineering seismic surveys from the Altai Republic, and 3D seismic data from Russian oil and gas fields. The results demonstrated robust extraction of the fundamental mode under various geological conditions and fully automated processing without parameter retuning.
This paper formulates the problem of constructing a depth image of small-scale scattering objects with true amplitudes preserved. The model of the recorded wavefield is investigated, along with methods for its inversion. Particular attention is paid to techniques that account for inhomogeneous (evanescent) waves, which are necessary for improving focusing. Based on the analysis performed, the limited capability of the standard Kirchhoff integral transformation for the correct imaging of small-scale inhomogeneities is demonstrated.
This study compares the regional geoelectric model of the TIPAGE-Alai profile along the 73.4° E meridian (Southern Tien Shan) with the distribution of earthquake hypocenters over a 25-year period (2000–2024) based on the International Seismological Center (ISC) catalog. The results demonstrate a correlation between deformation zones and the clustering of earthquake hypocenters, which contributes to a better understanding of geodynamics as a relationship between electrical conductivity, crustal deformation, and seismic processes in the region. These data highlight the tectonic significance of the Pamir–Tien Shan junction as an active intracontinental collision zone.
