The disaster would unfold in predictable stages. At first, the immense sulfur fumes spewing from the crater would combine with oxygen to form sulfur dioxide. Rising high into the atmosphere, the sulfur dioxide would react with ultraviolet light and water vapor to form sulfuric acid.
The resulting acidic clouds, like those on Venus, would be thick enough to cut the amount of sunlight reaching earth's surface by about 20%, the researchers said. That is enough to drop temperatures worldwide by more than 20 degrees Fahrenheit.
"The unique aspect of this is the unusual site with the sulfuric element in the ground," Baines said. "The asteroid not only caused the largest known impact on Earth, but the asteroid hit the one spot on Earth that would cause a worldwide cataclysm," he said. "Only 5% of the earth has this kind of sulfur-bearing rock."
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