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article imageOp-Ed: World’s largest mass extinction happened much faster — MIT

By Paul Wallis     Feb 10, 2014 in Science
Sydney - The Permian extinction, which almost annihilated life on Earth, was a comparatively sudden event. MIT scientists have now discovered that the extinction was caused by a massive increase of carbon, believed to have been caused by volcanic eruptions.
While major volcanic eruptions were a known factor in the Permian extinction, the implied speed and extent of their effects is a major finding.
Science Daily:
"We've got the extinction nailed in absolute time and duration," says Sam Bowring, the Robert R. Shrock Professor of Earth and Planetary Sciences at MIT. "How do you kill 96 percent of everything that lived in the oceans in tens of thousands of years? It could be that an exceptional extinction requires an exceptional explanation."
In addition to establishing the extinction's duration, Bowring, graduate student Seth Burgess, and a colleague from the Nanjing Institute of Geology and Paleontology also found that, 10,000 years before the die-off, the oceans experienced a pulse of light carbon, which likely reflects a massive addition of carbon dioxide to the atmosphere. This dramatic change may have led to widespread ocean acidification and increased sea temperatures by 10 degrees Celsius or more, killing the majority of sea life. But what originally triggered the spike in carbon dioxide? The leading theory among geologists and paleontologists has to do with widespread, long-lasting volcanic eruptions from the Siberian Traps, a region of Russia whose steplike hills are a result of repeated eruptions of magma.
The new theory about the Permian extinction is that it happened so fast that organisms couldn’t adapt to the new conditions. The Permian environment was well established on the single global land mass of Pangaea. The Permian extinction eliminated 90 percent of marine life, and approximately 70 percent of life on land. In effect, a thriving global ecology was almost obliterated.
The Permian extinction occurred prior to the reign of the dinosaurs, and is widely believed to have been the trigger for the beginning of the dinosaur era. The dinosaurs moved into vacant niches left by the previous population of reptiles and mammal-like reptiles.
MIT researchers discovered an interesting layering of alternate volcanic and fossil bearing rocks. The Siberian Traps are an area of volcanic rock, showing evidence of multiple large explosive eruptions during this time. There is also evidence of pyroclastic flows on a very large scale.
A similar prehistoric volcanic region is the Deccan Traps area, believed to have been active during the end of the Cretaceous era. The temptation to equate these regions with extinctions is obvious, but the Deccan Traps haven’t yet been accused of causing the Cretaceous extinction.
The sheer size of these volcanic areas is quite extraordinary. They are believed to been caused by a phenomenon called mantle plumes, in which hot rock rises from the mantle the surface.
The Traps are not, however, being referred to as super volcanoes. The only thing they have in common with super volcanoes is size. The theoretical super volcano under Yellowstone National Park approximates the sizes of the Siberian and Deccan Traps.
The new findings do raise quite a few questions about the physical mechanisms of extinction. It’s fair to say nobody was particularly surprised by the effects of additional carbon entering the ecosystem, but the speed of those effects is definitely new science.
While the volcanoes themselves may have been cataclysmic locally, their real effect was a sort of global poisoning. It’s basic biology. If you change the pH level of an environment, it affects all biological processes.
This is the sort of major finding which makes perfect sense after the event. For decades, people have been puzzling over the massive marine extinction during the Cretaceous period. Acidity would explain it.
It would be interesting to know whether or not atmospheric acidity is increasing at this point in time, too. If it is, the world may be in for a very turbulent time.
This opinion article was written by an independent writer. The opinions and views expressed herein are those of the author and are not necessarily intended to reflect those of DigitalJournal.com
More about Mit, Permian extinction, Marine acidity, atmospheric acidity, pH levels in environments
 
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