megaflood (Gilbert, 1890) describes this event. The last of the North American proglacial lakes, north of the present Great Lakes, has been designated Glacial Lake Ojibway by geologists. It reached its largest volume around 8,500 years ago, when joined with Lake Agassiz. But its outlet was blocked by the great wall of the glaciers and it drained by tributaries, into the Ottawa and St. Lawrence Rivers far to the south. About 8,300 to 7,700 years ago, the melting ice dam over Hudson Bay's southernmost extension narrowed to the point where pressure and its buoyancy lifted it free, and the ice-dam failed catastrophically. Lake Ojibway's beach terraces show that it was above sea level. The volume of Lake Ojibway is commonly estimated to have been about , more than enough water to cover a flattened-out Antarctica with a sheet of water deep. That volume was added to the world's oceans in a matter of months. The detailed timing and rates of change after the onset of melting of the great ice-sheets are subjects of continuing study. The Caspian and Black Seas (around 16,000 years ago) A theory proposed by Andrey Tchepalyga of the Russian Academy of Sciences dates the flooding of the Black Sea basin to an earlier time and from a different cause. According to Tchepalyga, global warming beginning from about 16,000 BP caused the melting of the Scandinavia Ice Sheet, resulting in massive river discharge that flowed into the Caspian Sea, raising it to as much as above normal present-day levels. The Sea of Azov rose so high that it overflowed into the Caspian Sea. The rise was extremely rapid and the Caspian basin could not contain all the floodwater, which flowed from the northwest coastline of the Caspian Sea, through the Kuma-Manych Depression and Kerch Strait into the Black Sea basin. By the end of the Pleistocene this would have raised the level of the Black Sea by some below its present-day level, flooding large areas that were formerly available for settlement or hunting. Tchepalyga suggests this may have formed the basis for legends of the great Deluge. Red Sea floods The barrier across Bab-el-Mandeb, between Ethiopia and Yemen, seems to have been the source of outbreak flooding similar to that found in the Mediterranean. The Lake Toba event, approximately between 69,000 and 77,000 years ago, caused a massive drop in sea levels, exposing the barrier and enabling