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The researchers found traces of a huge freshwater flood in the Arctic region that would have triggered a brutal climate change thousands of years ago.
In a five-year study that culminated this year, The glacier traversed what is now the Mackenzie River of Canada
Freshwater disturbed the deep current system of the Atlantic North, resulting in changes in the weather that triggered the Younger Dryas, a mini Ice Age in the northern hemisphere. Ice Age of the Quaternary Ice Age
Younger Dryas
Forty-five thousand years ago, the last Great Ice Age ended when the Earth's climate began to change interglacial state warmer. However, after a thousand years of transition, the northern hemisphere returned to glacial conditions during a period called Dryas Younger.
Named after the Dryas octopetala flower that thrived in the harsh environments of Europe at that time, the Dryas a progressive global warming that has unfolded for over 1000 years. This is according to the oceanographer Lloyd Keigwin, lead author of the new study published in the journal Natural Geoscience .
For years, experts have debated the cause of Younger Dryas. The popular theory is that it was triggered by a sudden influx of fresh water from melting glaciers and glaciers of North America.
Freshwater merged with the North Atlantic, disrupting the deep current system called Atlantic. Meridian overturning circulation. AMOC transports heat from the tropics to the North Atlantic, where it is released into the atmosphere
Source of freshwater flood
In 2013, the WHOI's Keigwin team, with geologists and geophysicists at the University of California at San Diego. The Scripps Institution of Oceanography and Oregon State University sailed in the Beaufort Sea north of Alaska, Yukon, and the Northwest Territories aboard the US Coast Guard Healy
. where the Mackenzie River flows into the Arctic Ocean. To do this, the researchers collected cylindrical samples of sediments found on the eastern slopes of the Mackenzie River.
They then badyzed fossil plankton encrusted with sediments, which led them to conclude that an abundance of glacial meltwater was crossing the Mackenzie River. "The signature of oxygen isotopes recorded in foraminifera shells in sediments has allowed us to trace the source of the glacial lake dump along the Mackenzie River 13,000 years ago," explains Neal Driscoll, co-principal investigator.
Implications for Current Climate Change Studies
Researchers plan to examine how much freshwater is circulating in the North Atlantic to trigger a sudden change in climate. They would also like to know how long it took for the flood of fresh water to cause the Younger Dryas.
Knowledge that can be learned from a future study could help experts look into Greenland ice caps and Arctic warming. "In the long run, I think the results of this paper will stimulate more research on the amount of freshwater actually needed to bring about a change in the system and the weakening of AMOC," says Keigwin.
In previous research conducted by OMSI experts, they found that AMOC has weakened since the mid-19th century. It is currently at its weakest point in 1,600 years. If conditions persist, researchers say that it could cause major disruptions in the United States, Europe and the Sahel region in Africa.
Photo: Rachel Hobday | Flickr
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