Tracking the local seismicity level in the active influence zone of the southern Uzbekistan reservoirs

Lutfulla Khamidov,Farkhod Artikov,Soqijon Mahkamov,Mahmud Turapov,Shavkat Suyunov,D Bazarov

doi:10.1051/e3sconf/202126402043

Abstract

Assessment of local seismicity caused by human engineering activity is a necessity after several earthquakes have been recorded in world practice, which destroyed a hydraulic structure, a dam and accompanied by human casualties.The Tupalang, Gissarak and Pachkamar reservoirs, operated in southern Uzbekistan, are located in the mountain system of the southern part of the Tien Shan seismogenic fault.According to the general seismic zoning, the zones where these reservoirs are located are classified as 8-9 magnitude shakes during strong earthquakes. Localisation of local earthquakes associated with the operation of these reservoirs is necessary for taking operational measures to prevent possible emergencies associated with an increase in the level of technogenic seismicity.Methods for assessing the local seismic regime were used to track the level of local seismicity. The catalogs of local earthquakes occurring in the zone of active influence of reservoirs have been compiled.The seismic activity levels and changes in the angle of inclination of the recurrence of earthquakes were determined for each object separately. The dependence of the variation in the level of local seismicity on the mode of operation of reservoirs has been revealed.Several evidence of the negative impact of large hydraulic reservoirs on the deformation and seismic state of the zones of influence of reservoirs in southern Uzbekistan have been identified.

Highlights

In the complex of studies that contribute to ensuring the geodynamic safe operation of reservoirs in Uzbekistan, digital seismic monitoring is becoming a new direction [1]
Seismic studies carried out earlier in the period 1973-1981 and in subsequent years showed that the territory of southern Uzbekistan is characterised by high seismicity, where earthquakes of magnitude 8 (M 7) can occur [11, 22]
Analysis of the total and background seismicity of the Hissarak, Pachkam Ar and Tupalang reservoir zones in Southern Uzbekistan has shown that the distribution of local earthquake focuses in the study area is different for different years

Summary

Introduction

In the complex of studies that contribute to ensuring the geodynamic safe operation of reservoirs in Uzbekistan, digital seismic monitoring is becoming a new direction [1]. It is based on the representative registration of seismic vibrations from small acts of brittle fracture in the side rock mass [2, 3]. Changes in the maximum of energy classes in the areas of reservoirs of southern Uzbekistan, calculated from representative seismological data, have shown that the possibility of the existence of signs of technogenic influence on the geodynamics of the area and the background seismicity of the region is quite comparable

Methods

Results

Conclusion