According to a study by the University of Alberta, Lake Agassiz, which flooded the northern hemisphere 12,000 years ago, was flowing out at the rate of 800 Olympic pools per second.
This discovery supports the theory that the Lake Agassiz flood has reversed warming and returned the Earth to an ice age.
The lake arose as a result of the active melting of glaciers at the end of the last ice age: in size it exceeded the area of all modern Great Lakes and occupied 1.5 million km² of territory. Agassiz began to form 16 thousand years ago, after the three-kilometer ice sheet of Lawrence at the top of the northern half of North America began to melt.
Geomorphological evidence suggests that at some point this lake suddenly overflowed. An international study by Sophie Norris, a former science graduate student, clarified how much water was discharged.
In order to find out the volumes of water and the rate of spill, the authors of the work used sedimentary materials to estimate the strength of the water, and also measured more than 100 cross-sections of the valley to understand the dimensions of the streams. The team also created a gradual dam failure model using information on the internal compliance and instability of bedrock in the region.
As a result, the authors came to the conclusion that the rate of water discharge was 2 million m³/sec: this volume is ten times greater than the flow of the Amazon River. In general, 21 thousand m³ poured from Agassiz in nine months – approximately the same volume of water is in all the Great Lakes combined.
Moreover, the flood occurred during a period called the Younger Dryas – then the northern hemisphere was just emerging from the ice age, but cooled again due to cold water.