Interestingly! Black Sea is an earthquake hot zone
It's an earthquake hazard area. Although several earthquakes have been reported in and around the Black Sea, the greatest recorded magnitude was 7.2 in the 1901 Black Sea earthquake (also known as the Balchik earthquake in Bulgaria). The mainshock triggered a 1-16 foot tsunami, wreaking havoc on the Romanian and Bulgarian shores. The aftershocks continued four years longer.