Following the large September event, natural gas that was released from the sea floor created flames that were visible along the coastline, and was accompanied by bright flashes and explosions.

[3] The September event struck the Crimean Peninsula with a moment magnitude of 6.7 at a depth of 35 kilometres (22 mi).

The shock was centered about 20 kilometres (12 mi) southeast of Yalta and had a maximum perceived intensity of VIII (Damaging) on the Medvedev–Sponheuer–Karnik scale.

[1][3] Numerous, very large flames were seen offshore Sevastopol, Cape Lucullus, and Yalta in the early morning following the September event.

The flames and explosions were attributed to methane or other hydrocarbon gasses that had been released from the seabed and spontaneously combusted in Phosphine (a self-igniting gas).