Outburst flood
In geomorphology, an outburst flood—a type of megaflood—is a high-magnitude, low-frequency catastrophic flood involving the sudden release of a large quantity of water.
Landslides, lahars, and volcanic dams can also block rivers and create lakes, which trigger such floods when the rock or earthen barrier collapses or is eroded.
A landslide dam on Sichuan's Dadu River, created by an earthquake ten days earlier, burst and caused a flood that extended 1,400 km (870 mi) downstream and killed 100,000 people.
Rose calls it the "Gulf Oasis" which may have been a demographic refuge fed by the Tigris, Euphrates, Karun, and Wadi Batin rivers.
As ice-dam configurations failed, a series of great floods were released from Lake Agassiz, resulting in massive pulses of freshwater added to the world's oceans.
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.
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[broken anchor], resulting in massive river discharge that flowed into the Caspian Sea, raising it to as much as 50 metres (160 ft) above normal present-day levels.
The Lake Toba event, approximately between 69,000 and 77,000 years ago, caused a massive drop in sea levels[citation needed], exposing the barrier and enabling modern Homo sapiens to leave Africa via a route other than Sinai.
A gently upfolding chalk ridge linking the Weald of Kent and Artois, perhaps some 30 metres (100 feet) higher than the current sea level, contained the glacial lake at the Strait of Dover.
[13][11] A catastrophic flood refilled the Mediterranean Sea 5.3 million years ago, at the beginning of the Zanclean age that ended the Messinian salinity crisis.
[14] The flood occurred when Atlantic waters found their way through the Strait of Gibraltar into the desiccated Mediterranean basin, following the Messinian salinity crisis during which it repeatedly became dry and re-flooded, dated by consensus to before the emergence of modern humans.
