Modern tectonic events in near-bottom sediments of the Middle Caspian Sea

The Central Caspian western border is a seismically active region with contrasting combinations of mountain clinoforms and troughs. Intense troughing started here at the end of the Pliocene and remained uncompensated by sediments. Using high resolution seismoacoustic profiles associated with earthquake catalogs and also some additional data, this study investigated the correlation between modern seismic events and deformation structures in the seabed sediments of the Derbent Basin in the western part of the Middle Caspian Sea. The results showed that the seismic activity and the sediment disruption vary across the basin, and can be classified into four areas: single deformations, western slope, deep basin north-east area, and deep basin south area. The study revealed that the Caspian Sea is a tectonically active region, and that the seismic events can trigger high pressure and hot fluid to seep through the weak zones in the sediments. This paper also presents some interesting observation on seismoacoustic profiles including tens of disruptions in sediment structure and disjunctions in seafloor relief, fault groups, gas pipes, and horizontal zones of non-correlation.