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Researchers have found evidence that a flood that occurred more than 12,000 years ago and emptied an ancient lake at the speed of more than 800 Olympic swimming pools per second could have plunged the Earth back into an ice age.
A team of experts – led by researchers at the University of Alberta – has found evidence that glacial Lake Agassiz has started to flow northwest into a channel known as the Clearwater-Athabasca Spillway .
This spill may have caused the Younger Dryas cooling event some 13,000 years ago.
The old lake, which no longer exists, covered an area of 580,000 square miles in present-day southern Manitoba, central Saskatchewan to the border with Alberta.
Researchers including Sophie Norris (pictured) have found evidence that a 12,000-year-old flood that drained a lake at speeds of more than 800 Olympic swimming pools per second may have plunged Earth back into an ice age.
The old lake, which no longer exists and which covered an area of 580,000 square miles in present-day southern Manitoba, central Saskatchewan to the border with Alberta
Researchers – using sedimentary evidence, more than 100 valley cross-sections, and a model of bedrock erodability and lake size – estimated that at the peak of the spill, 2 million cubic meters of water were poured out every second.
“One suggestion is that the drainage of meltwater from glacial Lake Agassiz, a large ice dam lake in central North America, into the surrounding oceans may have affected ocean circulation, contributing to this climate event,” the researchers wrote in the study.
It is likely that ‘catastrophic meltwater flowing into the Arctic Ocean’ occurred over a 6 to 9 month period during the Younger Dryas, but it is not yet known if this happened. at the start of the event.
“We know that a significant discharge passed through the area, but the rate of discharge or the magnitude was pretty much unknown,” lead study author Sophie Norris said in a statement.
Over a period of approximately nine months, approximately 5,000 cubic miles (21,000 cubic kilometers) were drained from the lake, roughly the equivalent of all of the Great Lakes combined.
Using sedimentary evidence, more than 100 valley cross sections, and a model consisting of a gradual failure of the dam with bedrock erodability and lake size, the researchers estimated that 2 million cubic meters of water were being dumped every second at the height of the spill. , making it one of the biggest known floods on Earth.
For comparison, that’s about 10 times what the Amazon River pours out every second.
Over a period of approximately nine months, approximately 5,000 cubic miles (21,000 cubic kilometers) were drained from the lake, roughly the equivalent of all of the Great Lakes combined.
The ancient lake formed after the Laurentian Ice Shield began to melt about 16,000 years ago, creating a dam that kept meltwater from entering Hudson Bay.
The ancient lake formed after the Laurentian Ice Shield began to melt about 16,000 years ago, creating a dam that prevented meltwater from entering Hudson Bay.
“What I find deeply satisfying is that modern hydraulic modeling, when applied to evidence preserved in the landscape, shows how a phenomenal flood spread 12,000 years ago,” said Paul Carling. , researcher and co-author of the University of Southampton study.
“When all the uncertainties are taken into account, the result remains quite solid. ”
While scientists aren’t sure exactly what caused the Earth to fall back into an ice age, the lake flood theory is certainly plausible, study co-author Froese added.
“We don’t know for sure that the flood caused the Earth to fall back into the Ice Age, but certainly if you put that much water in the Arctic Ocean, the models show that you get a cooling of the hemisphere’s climate. North.”
Researchers will then try to find out if the flooding occurred at the start of the Younger Dryas climate event, which could be the root cause, or if it was just part of other events.
It is also possible that the flooding has swept away the region’s vast oil sands, a region of loose sand, water and clay that also contains some form of petroleum.
“The oil sands region is mostly in the channel formed by this flooding,” Norris explained. “There would have been a tremendous amount of Quaternary material on top of that, as there is around it, but it was exposed in Fort McMurray by this huge event.”
The study was published last month in Geophysical Research Letters.
There are several theories as to the causes of the Younger Dryas cooling event which lasted approximately 1,500 years.
In June, a separate group of researchers said a cosmic impact, likely an asteroid, hit Earth and likely triggered climate change for the younger Dryas.
This change was potentially the “most devastating impact since the extinction of the dinosaurs” and resulted in a mini ice age that lasted for more than 1,000 years.
Several other studies over the years have supported the theory of an ancient asteroid strike.
Others, however, believe that the Younger Dryas’ cooling event was caused by other methods. In 2020, another study suggested it was caused by ancient volcanic eruptions, not meteor impacts.
Some have even suggested that an hour-long hailstorm from outer space plunged the planet into the Mini Ice Age.
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