Ice Age Dam Collapse Impacted Ocean Circulation, Climate
The catastrophic failure of an ancient, ice age dam had a major influence on climate and ocean circulation, where large volumes of fresh water were released from a massive South American lake at the end of the last Ice Age. A study found that this amount of water was significant enough to change the circulation of the Pacific Ocean.
"This study is important because we are currently concerned about the volumes of fresh water entering the oceans from the melting ice sheets in Greenland and Antarctica and this gives us an indication of the likely effects," Neil Glasser, lead author of the study, said in a news release.
The team found that the lake was about one third the size of Wales, where it drained on numerous occasions between 13,000 and 8,000 years ago, with devastating consequences. The lake covered approximately 7,400km2 and contained about 1500km3 of fresh water. This ancient lake now extends over Lago General Carrera in Chile and Lago Buenos Aires in Argentina, according to the researchers. It was once held by a massive ice sheet, however, it began to drain rapidly as the ice sheet was reduced in size.
The researchers noted that as the lake released about 1150km3 of fresh water from melting glaciers, which flowed into the Pacific and Atlantic oceans. This amount of water is equivalent to 600 million Olympic-sized swimming pools.
"This had a considerable impact on the Pacific Ocean circulation and regional climate at the time. The fresh water would have sat on top of the salt water as it spread out so it affected the regional ocean currents," Glasser, said. "The event affected the whole of southern South America and would have led to lower rainfall in winter and cooler ocean and air temperatures around Cape Horn, with the effects felt as far east as the Falkland Islands."
The team gathered sediment deposits, which were released by the former lake to help them to determine the age of the lake drainage events.
The findings of this study were published in Scientific Reports.
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