The aftershock processes of strong earthquakes in the Western Caucasus

Strong earthquakes in the Western Caucasus can disrupt gas hydrate layers along fault zones, leading to nonrelaxation aftershock processes. Researchers analyzed four significant quakes—including the 1991 Racha and 2012 East Black Sea events—and found that the latter deviated from typical aftershock behavior due to fluid-dynamic instability caused by main shock destruction of gas hydrates. Using the LPL relaxation model and ETAS triggered seismicity model, they revealed distinct aftershock characteristics tied to fault zone properties, highlighting a rare seismic mechanism linked to subsurface geological changes.

Baranov, S. V., & Gabsatarova, I. P. (2015). The aftershock processes of strong earthquakes in the Western Caucasus. Izvestiya, Physics of the Solid Earth, 51(3), 448–458. https://doi.org/10.1134/s1069351315030015