Actually, 14,000 ya the ice age was already in retreat, but then not quite 13,000 ya something severe happened and drove us back into the Younger Dryas 1500 year colder period. OK, Sunken Civ, time for Firestone’s book.
It was also interesting that, from the way the text reads, that the human remains were under basalt. That could mean volcanic activity, or it could mean that basaltic debris later covered the remains through erosion or whatnot.