As far as we know, there isn't an army of dolphins wielding chainsaws beneath the Black Sea. And hopefully no Elder God is waking from its millennia-long slumber. But the ice around Odessa is singing and squeaking all the same.
"Singing" ice has been known to happen as ice shifts and changes in response to external stimuli. But this ice sounds a bit less like it's singing and a bit more like it's crying out for help.