Ancient eruptions may have changed climate.

Drilling into the sea floor south of Haiti has uncovered conclusive ashy evidence that multiple massive volcanic eruptions occurred roughly 55,000,000 years ago in the Caribbean Basin. Those cataclysmic events appear to have caused abrupt inversion of ocean waters, triggering one of the most dramatic climatic changes ever, according to Timothy Bralower, associate professor of geology, University of North Carolina at Chapel Hill, a member of the team that discovered the eruptions.

The inversion caused release of massive amounts of sea floor methane into the atmosphere, leading to global warming and possibly speeding evolution of countless new plant and animal species, including many primates and carnivores. At the same time, close to half of all deep-sea animals went extinct, asphyxiated in the suddenly warmer and stagnant deep waters.

"We found multiple very distinct blue, green, and occasionally red volcanic ash layers that were very different from whitish-gray sediments above and below them in the core samples," Bralower indicates. "The time those ash layers--direct evidence of volcanic eruption--were deposited corresponds to the beginning of a known period of rapid warming of the Earth. This is the first evidence for a major volcanic episode at that time in the Caribbean.

"Many geologists are interested in this interval 55,000,000 years ago because we don't know of any other geologic period when warming occurred so precipitously, and warmth covered the globe like this. The million-dollar question is what triggered the sudden burp of methane. A dramatic climatic change had to have occurred first."

The ashy evidence...