Ph.D. Theses


Effect of Mingachevir water basin territory on seismicity

Applicant: Shirin Karimbala Islamova

Speciality: 2507.01- Geophysics, methods of geophysical prospecting of minerals

Field of science: Earth sciences


Relevance and development of the topic:
Intensive development of construction of residential buildings and industrial facilities in the country requires a thorough study of the degree of earthquake danger for individual cities, settlements and construction sites. The construction of hydraulic structures creates the need to address a number of issues related to their operation. The revitalization of the landslide process, especially in areas adjacent to hydraulic structures, requires the reworking of shores as a result of the deterioration of the reservoir, the elimination of the process of pumping rivers and siltation of shores with recycled products.

The study of the seismicity of the Mingachevir watershed, located on the southern slopes of the Greater Caucasus and the middle Kura basin, which is one of the most seismically active regions of Azerbaijan, is of particular importance in this regard. Obtaining detailed engineering and geological information about the area and forecasting dangerous geological processes is of great importance for the construction and operation of industrial and civil facilities.

The construction of the Mingachevir complex of hydro-technical facilities has led to the creation of large-scale reservoirs that create completely new conditions for the coast and coastal slopes. Increased seismic activity and destructive earthquakes in recent years, especially in the areas of large hydraulic structures, have made it necessary to establish and conduct a system of seismological monitoring in the Mingachevir reservoirs.

The study of natural and man-made processes in the geological environment by geophysical methods is the most pressing problem of today. In the study of seismic processes of geophysical methods, it is possible to study and predict the dynamics of this process by determining the seismicity as a result of its application and monitoring the change of geophysical fields over time.

Object and subject of research:
Influence of Mingachevir water basin and its level change on seismicity and exogenous geological processes of the area.

Research goals and objectives:
Study of the impact of changes in the water level in the Mingachevir water basin on the formation of artificial earthquakes in the region, the creation of dams to change the seismic situation.
  1. Analysis of macroseismic and instrumental data on seismic events
  2. Distribution of weak and medium earthquakes in space and time
  3. Construction of earthquake epicenter mechanisms and assessment of stress-strain state of the environment
  4. Carrying out seismotomographic works
  5. Study of the impact of strong earthquakes on Mingachevir water basin
  6. Study of tension situation in the territory of Mingachevir water basin on the basis of Pearson correlation coefficient.
  7. To study the impact of changes in water levels on seismicity and exogenous geological processes in the area.

Research methods:
During the dissertation work on the basis of materials obtained in the zone of Mingachevir water basin on the basis of telemetry stations of the Republican Seismological Service Center, geological-geophysical fund materials of the Institute of Geology and Geophysics of ANAS, State Oil Company of Azerbaijan Republic Geophysics and Engineering Geology Production Association, Materials of the Ministry of Ecology and Natural Resources were used. The parameters of earthquakes that occurred during 1980-2017 were used in the implementation of the reports. Complex analysis of seismic and geological data was conducted in Antelope, ArcGIS10.1, Surfer, Fa_major, Moment Tenzor, MathLab and DIMAS programs.

The main provisions of the defense:
  1. Formation of seismicity in connection with the operation of the Mingachevir reservoir, the dynamics of development of seismic conditions and the state of tension-deformation of the environment.
  2. The impact of changes in the water level of the Mingachevir reservoir on the seismicity of the area and exogenous geological processes.
 
Scientific novelty of the research:

  1. Analysis of the long-term seismicity of the Mingachevir water basin zone, as well as adjacent areas, showed that an increase in weak seismicity has been observed since 1956.
  2. From my observations, I came to the conclusion that the violation of the water level balance in the Mingachevir reservoir affects the formation of weak earthquakes in these areas.
  3. It has been determined that weak earthquakes occur at a depth of 12-34 km within a radius of 30 km from the center of the reservoir within 1-3 months after the completion of the reservoir filling, which confirms their man-made nature - directed seismicity.
  4. Seismological and geodynamic surveys conducted around the Mingachevir water basin showed that 80 landslides were recorded in the direction of SW-NE of Bozdag slope, which lasted 7-12 seconds, at a depth of 18-50 m.

Theoretical and practical significance of the research:
The results of the study can be used to assess the potential seismic hazard around the Mingachevir Reservoir and other artificial reservoirs and to take measures to reduce seismic risk.

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