July 22, 2011
Mass Extinction May Have Been Caused By Giant Earth Burp
The release of a huge amount of methane gas may have caused a massive, prehistoric extinction that gave way to the arrival of dinosaurs as the dominant life form on earth, according to a new study.
Micha Ruhl and his team of researchers from the Nordic Center for Earth Evolution at the University of Copenhagen in Denmark suggest that the mass extinction of half of Earth's marine life over 200 million years ago was a result of a huge release of carbon methane into the atmosphere, which led to an increase in atmospheric temperature around the globe.
Organisms and ecosystems at the time were not able to adapt to the hotter environment.
"We measured the isotopes of carbon in plants, from before the mass extinction event and then after the mass extinction," Ruhl told Fox News. "We found two different types of carbons and the molecules that were produced during that event. So we started thinking of other sources of carbon that could have changed the atmosphere."
Original theories suggest that the extinctions were caused by a destructive wave of volcanic activity, which was brought on by continental shift when Pangaea broke apart.
However, the researchers discovered that the volcanic eruption happened 600,000 years before the end of the Triassic Period, but the mass extinctions occurred only 20,000 to 40,000 years prior.
Calculations by Ruhl's team found that over 12,000 gigatons of methane was pumped into the atmosphere during the final years of the Triassic.
Although the researchers do not believe that the volcanoes caused the actual mass extinction, they suggest that it somehow indirectly set the events in motion by triggering the methane release.
"A small release of carbon dioxide from volcanism initiated global warming of the atmosphere, increasing temperatures in the oceans," Ruhl says.
"Methane is stored in the sea floor "“ it's a molecule which is caught in some kind of ice structure. As soon as the temperatures got above a certain threshold, the ice melts and that methane was released."
"We could potentially trigger a small increase in ocean temperatures, which triggers methane release," he says.
"But it's difficult to quantify how much methane is in the ocean these days. Maybe we have less methane in seafloors now. Maybe we have more."
"People are worried nowadays that the release of carbon dioxide from fossil fuel burning could melt glaciers in the same way," Ruhl tolf Fox News.
However, Ruhl does note that events that occurred when the planet was dramatically different are hardly comparable to the earth today.
"What we don't know is what the thresholds are today," he explains.
"We have to remember that the world in the past was a very different. All the continents were still together, there were no glaciers. Ocean currents were probably very different."
He does not want the finding to bring panic, but instead Ruhl says that better understanding of the Triassic Period extinction could help with research in the field of climate change today.
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