On the Regular Periodicity of the Seismic Process in the Eastern Caucasus over the Past Two Centuries

Abstract

More than 30 years ago, the existence of a regular quasi-cyclic regime of seismicity was revealed at a qualitative level for the eastern regions of the North Caucasus (Dagestan and Chechnya) on an area of 300 × 300 km for the period 1800–1985. The regularity was that the level of seismicity during one cycle lasting 10–30 years decreased from the peak event (magnitude 5.0–6.5) to the background values, followed by a rapid increase in seismicity (during 2–3 years) until the next peak event. This hypothetical phenomenon was rigorously analyzed by us in a formalized way on the data of an extended catalog, including the year of 2022. The obtained result confirmed the existence of a regular quasi-cyclical change in the level of seismicity in the eastern part of the North Caucasus as a natural phenomenon. The revealed pattern can be used for medium-term prediction of seismicity and for testing seismicity models of the region.