Paleoseismological studies in the pleistoseismic area of the 1668 and 1902 Shamakhi earthquakes

The Caucasus region located at the junction of the Eurasian and Arabian tectonic plates is a key area for understanding continental collision processes and their impact on seismic activity.The aim of this work is to analyze the region's tectonic processes, seismic history, and the risks associated with potential large earthquakes.The study employs modern methods including satellite imagery, GNSS data, drone-based modeling, and paleoseismic trenching.In April-May 2022, a team of scientists from the University of Oxford, in collaboration with early-career researchers from the RSS, carried out the first geological fieldwork in Azerbaijan focused on paleoseismology and active tectonic processes.Two trenches were analyzed.One of the key findings was the identification of active faults, such as the Aghsu fault, and evidence of surface ruptures associated with historical earthquakes.Two surface rupture events (1713-1895 and 1872-2003) were identified likely linked to the surface displacements caused by the 1668 and 1902 earthquakes, which inflicted significant damage on the city of Shamakhi.Our reassessment of the 1902 earthquake suggests its magnitude may have reached Mw 7.4, whereas earlier estimates placed it at M 6.9.Additionally, evidence of a surfacerupturing earthquake dated between 334 and 118 BCE was found in a second trench located 60 km west of Aghsu near Goychay along with signs of another possible event within the past 2000 years.This work highlights the importance of continued field investigations to better constrain fault lengths, assess historical earthquake magnitudes, and improve regional seismic hazard maps.