Ph.D. Theses

Seismogeodynamics Lower Kura depression based on new geophysical data

Farajov Vugar Alish

2507.01 - Geophysics, geophysical methods of reconnaissance of the minerals

Lower Kura depression is particularly seismic activity. But before this area is referred to as aseismic area. Recently, however, the earthquake analysis showed that the studied area is not aseismic, but on the contrary is of particular seismic activity. On mapping tangible epicenters of earthquakes in the northern part of the Lower Kura depression, the area where the city of Shirvan (2011) and Hajigabul district (2014), catches the eye as a special seismically active area. This result proves the study of earthquakes that have occurred in recent years. Not overlooked and other parts, which are to some extent active at different times.

As is known, earthquakes occur along deep faults. A tangible earthquake along the deep faults passing in the zone of the Lower Kura depression occurs mainly in Hajigabul, Shirvan, in the zone of Lake Sarysu, Saatli, Sabirabad, Imishli and Neftchala. These earthquakes are connected with active segments of such faults as - Palmir-Absheron, Savalan-Absheron, Akhvay, Tairaljachay-Salyan, and Alazan-Agrichay-Alyatsky.

We have attempted in this work to provide moment tensor solutions for small and moderate earthquake in the Lower Kura depression. The analysis was performed using data coming from the permanent Azerbaijan broadband seismic network (Kinemetrics Inc., USA), run by 2003. The source depth and focal mechanisms are determined using a grid search technique. The method allow time shifts between synthetics and observed data in order to reduce dependence of the solution on the assumed velocity model and on earthquake locations. In order to get reliable source mechanisms, using waveforms, it is necessary to compute synthetic seismograms, which in turn requires a reasonable velocity/attenuation model for generating Green’s functions. This method, successfully applied also in the case of earthquakes with magnitude lower than 3 in other regions (D’Amico et al. 2010, 2011, 2013), furnishes good-quality solutions in the area in a magnitude range not properly represented in the official databases and in the major literature. The study of faulting parameters and depths of the small-to-moderate-size events can contribute much to our understanding of the regional stresses.

On the investigated territory, I compiled seismic sections in two directions, the locations of earthquakes of different magnitude, the dependence on the depth of solutions to the focal mechanisms of earthquake were studied, and their interrelation with geological profiles was examined.

The north and south-western part of the investigated territory of the Lower Kura depression is seismically active.