Mass Extinction Caused by Deadly 'Earth Burp' -
A massive, long-ago extinction was once thought to have been caused by a destructive wave of volcanic activity. Scientists now point their fingers at another culprit.
A giant, deadly “Earth burp.”
Micha Ruhl and researchers from the Nordic Center for Earth Evolution at the University of Copenhagen in Denmark have found that the mass extinction of half of Earth’s marine life over 200 million years ago was likely the result of a giant release of carbon methane in the atmosphere.
This massive methane “burp” led to an increase in atmospheric temperature around the globe -- and organisms and ecosystems were simply unable adapt to their hotter environment.
“We measured the isotopes of carbon in plants, from before the mass extinction event and then after the mass extinction. We found two different types of carbons and the molecules that were produced during that event,” Micha Ruhl told FoxNews.com. “So we started thinking of other sources of carbon that could have changed the atmosphere.”
The original theory blamed the extinction and atmospheric change on carbon released during a period of intense volcanism -- a large surge in volcanic activity brought about by continental shift when Pangaea broke apart. But Ruhl and his partners discovered that this volcanic episode occurred 600,000 years prior to the end of the Triassic Period. The mass extinction occurred only 20,000 to 40,000 years prior.
Extensive calculations and research by Ruhl’s team revealed that the burp pumped over 12,000 gigatons of methane into the atmosphere during the final years of the Triassic. While volcanism was revealed not to have caused the extinction itself, the researchers believe that the volcanoes indirectly set the events in motion by triggering the methane release.
Read more: http://www.foxnews.com/scitech/2011/07/21/mass-extinction-caused-by-earths-burp/#ixzz1Spbg7WW4
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