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RELATED: Saga of Pliocene Exile
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The cataclysmic flood that wasn’t
https://knowablemagazine.org/content/art...iterranean
INTRO: On October 6, 1970, the deep-sea drilling vessel Glomar Challenger returned to port in Lisbon, Portugal, bearing a cargo that would revise history. During its 54-day voyage, the Challenger had punched 28 holes into the bottom of the Mediterranean Sea.
The recovered cores pointed toward a startling conclusion: About 6 million years ago, the sea had turned into a desert: a vast, barren, salt-filled bowl more than two kilometers deep. Half a million years after that, the Atlantic Ocean had burst through what is now the Strait of Gibraltar and unleashed the largest flood in history.
Kenneth Hsü, an oceanographer who was one of the two lead scientists on the Challenger expedition, imagined the scene vividly in the December 1972 issue of Scientific American:
“Cascading at a rate of 10,000 cubic miles per year, the Gibraltar Falls would have been 100 times bigger than Victoria Falls and 1,000 times more so than Niagara.… What a spectacle it must have been for the African ape-men, if any were lured by the thunderous roar.”
The catastrophe story was a hit: David Attenborough filmed a documentary about it, and Gibraltar even issued a 5-pence stamp portraying the “3,000-metre waterfall.” The two hypotheses — first, that the Mediterranean Sea became landlocked during a half-million-year period known as the Messinian salinity crisis, and second, that it was restored by a cataclysmic deluge through the Strait of Gibraltar, dubbed the Zanclean flood — have been conventional wisdom among geologists for more than 50 years.
However, fresh doubts have arisen recently about every part of this story, from the mega-desert to the mega-Niagara. Many geologists have argued for a much briefer desiccation followed by a far more gradual refilling of the Mediterranean. Some think that the Mediterranean never completely disconnected from the Atlantic at all. “The idea of a megaflood, and the data that supports it, are mostly flawed,” says Guillermo Booth Rea of the University of Granada in Spain.
The most startling recent twist is that the floodway, if there was one, may not have been anywhere near the present-day Strait of Gibraltar, which separates southern Spain from Morocco. For 50 years, new research suggests, we have been looking for signs of a megaflood in the wrong place... (MORE - details)
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The cataclysmic flood that wasn’t
https://knowablemagazine.org/content/art...iterranean
INTRO: On October 6, 1970, the deep-sea drilling vessel Glomar Challenger returned to port in Lisbon, Portugal, bearing a cargo that would revise history. During its 54-day voyage, the Challenger had punched 28 holes into the bottom of the Mediterranean Sea.
The recovered cores pointed toward a startling conclusion: About 6 million years ago, the sea had turned into a desert: a vast, barren, salt-filled bowl more than two kilometers deep. Half a million years after that, the Atlantic Ocean had burst through what is now the Strait of Gibraltar and unleashed the largest flood in history.
Kenneth Hsü, an oceanographer who was one of the two lead scientists on the Challenger expedition, imagined the scene vividly in the December 1972 issue of Scientific American:
“Cascading at a rate of 10,000 cubic miles per year, the Gibraltar Falls would have been 100 times bigger than Victoria Falls and 1,000 times more so than Niagara.… What a spectacle it must have been for the African ape-men, if any were lured by the thunderous roar.”
The catastrophe story was a hit: David Attenborough filmed a documentary about it, and Gibraltar even issued a 5-pence stamp portraying the “3,000-metre waterfall.” The two hypotheses — first, that the Mediterranean Sea became landlocked during a half-million-year period known as the Messinian salinity crisis, and second, that it was restored by a cataclysmic deluge through the Strait of Gibraltar, dubbed the Zanclean flood — have been conventional wisdom among geologists for more than 50 years.
However, fresh doubts have arisen recently about every part of this story, from the mega-desert to the mega-Niagara. Many geologists have argued for a much briefer desiccation followed by a far more gradual refilling of the Mediterranean. Some think that the Mediterranean never completely disconnected from the Atlantic at all. “The idea of a megaflood, and the data that supports it, are mostly flawed,” says Guillermo Booth Rea of the University of Granada in Spain.
The most startling recent twist is that the floodway, if there was one, may not have been anywhere near the present-day Strait of Gibraltar, which separates southern Spain from Morocco. For 50 years, new research suggests, we have been looking for signs of a megaflood in the wrong place... (MORE - details)