Problems of Engineering Seismology: article

Аnnotation: A good archaeological study of the monuments of Mount Opuk allows, in the very first approximation, to outline the chronology of seismic events. The revealed deformations of building structures individually, and even more so in their totality, indicate the seismic reason for their origin. In the ancient building structures and cultural layers of archaeological sites in the region of Mount Opuk in the southeast of Crimea, numerous ruptures were identified in the ancient building structures and cultural layers we studied. Cracks found in the ash pan, fading in the layer of the end of the II-III century. AD is typical seismogenic fractures. It is possible that this earthquake occurred at the end of the 3rd century. Traces of two earthquakes were found at the settlement “Kholm A”. The consequences of the first earthquake are reflected in the systematic clockwise rotation of the submeridional walls around the vertical axis. Seismic vibrations during this earthquake acted at an angle at the mentioned walls along the NNE-SSW axis. The building survived and was repaired (buttress wall at the northern face of the southern wall of room “A”). In the second, more powerful earthquake, the seismogenic rupture came to the surface and displaced the SE part of the structure, almost completely destroying it. The time of the death of this room is the beginning of the 4th century BC. Traces of catastrophic destruction were found in the ruins of a citadel on the upper plateau of Mount Opuk. The NW tower of the citadel experienced significant deformations, traces of two earthquakes were found in the barracks, the western curtain and the citadel wall were severely destroyed. Significant seismic deformations were also studied on the so-called “Eastern defensive wall”, most likely a synchronous citadel. The citadel completely ceases to exist in the 1st half of the 6th century. AD, possibly during a strong seismic event, which ends the process of destruction of the infrastructure of ancient Cimmerian. Before the arrival of the carriers of the Saltovo-Mayatsk culture on the territory of the Kerch Peninsula, life on Mount Opuk and in its vicinity temporarily stops. Traces of two earthquakes were found in the estate of the Saltovo-Mayatsk (“Khazar”) period of the early Middle Ages in the settlement “Above the source”. The first seismic event led to a counterclockwise rotation of all submeridional walls of the estate around the vertical axis. This fact means the action of seismic vibrations at an angle to these building elements - along the NW-SE axis. The building resisted, only a buttress wall was added to it from the southern - outer facade of the eastern room wall. The second earthquake was stronger. Intense seismic vibrations brought down the repaired wall and the wall-crepida that was holding it in the southern direction, from the side of the source of elastic vibrations. The estate finally perished in the 30s - 40s of X century. AD Expressive traces of strong earthquakes are observed in the relief of Mount Opuk. According to the collected data, the main rupture on the mountain is seismotectonic, however, the magnitude of the displacement was multiplied by the sliding of the rock mass towards the sea. The fault is a segment of the South Kerch fault zone, which is traced along the Black Sea coast. The last seismotectonic displacement is dated in the area of the ancient city of Kiti in the 3rd century AD, or immediately after. Over the past 4000 years or so, at least three seismotectonic movements have occurred here with a total displacement of at least three meters. The tracked minimum length of an activated segment is 20 km. The minimum event magnitude can be estimated using the known global relationships for the parameters of seismic ruptures within M