Comparing geologic structural mapping techniques in tectonically active region of Lake Van using gravity and seismological data

The Van Lake region is situated within the boundary of the collision zone between the Arabian and Eurasian plates, which has resulted in the formation of a variety of geological structures, including faults, volcanoes, and uplifted mountain ranges. A comprehensive understanding of these structures can yield significant information pertaining to the region’s tectonic history, as well as potential tectonic hazards. In the present study, several structural mapping techniques, including lineament detection techniques [Horizontal Gradient Magnitude (HGM), Analytic Signal (AS), and Tilt Angle] and curvature analysis attributes (Differential, Gaussian, Mean, and Shape Index), were analyzed and compared the results obtained using both Earth Gravity Model 2008 (EGM2008) Bouguer gravity and seismological data, with the goal of determining the most effective (suitable) edge detection method in order to gain a better understanding of high-stress regions and areas of potential seismic hazard in the vicinity of Van Lake. It is of great importance to investigate the behavior of faults and the curvatures of structural features within the crust, as they play a significant role in determining the distribution of stress, and subsequently, its impact on surface structures. The results show that HGM and AS are effective in defining fault strikes and trends, while Gaussian curvature attributes can detect lineaments and structural edges. Differential curvature attributes were found to be best suited for complex tectonic regions. The study also reveals a coherent relationship between fold orientation and fault strikes with the regional principal stress direction. The current study has focused on a region characterized by a significant negative anomaly, which appears to be a valley-like fold structure with a highly inclined interlimb angle. This area, referred to as the “silent” zone, is seismically quiet with regard to earthquakes and faults. However, focal mechanism results support the orientation of the interlimb angle fold in the vicinity of this region. The existence of a strong negative anomaly in the eastern part of the study area highlights the requirement for additional geological field observations and seismic surveys to evaluate the potential earthquake hazards. In the course of comparing various structural mapping techniques, it was concluded that the application of second-order vertical derivative of gravity potential is a suggested approach for identifying the edges