Acid Rain and Ozone Depletion Caused Great Dying of Species 250 Million Years Ago

Researchers have put an end to the mystery surrounding the great die off that occurred 250 million years ago. A latest study claims that acid rain and ozone depletion was responsible for the mass extinction.

An unknown event that took place some 250 million years wiped put 90 percent of life on our planet. This mass extinction in Earth's history called 'The Great Dying' brought an end to the Permian period.  The loss of vast biodiversity took Earth nearly 10 million years to recover. Researchers have proposed the possible mechanism that would have triggered a massive extinction-96 percent marine species and 70 percent terrestrial vertebrate species. They believe a combination of several factors coincided and caused the die-off, including  environmental change, climate change, natural events like coal/gas fires, nearby supernova, impact of asteroid and volcano eruptions in Siberia.

But researchers from the Department of Terrestrial Magnetism Carnegie Institution of Washington that included the Director Linda Elkins-Tanton confirm that the atmospheric change induced by volcanic eruption is what caused the extinction of species.

This mass extinction created a world for the rise of dinosaurs and fossil records reveals that it took 10 million years after the extinction for the ecological diversity to fully recover.

 A major culprit for the mass extinction was the gas emitted from the large swath of volcanic rock in Russia called the Siberian Traps. The team led by Benjamin Black of the Massachusetts Institute of Technology, used 3D modeling technique to predict the impact of the gas that was released from the Siberian Traps at the end of the Permian atmosphere.

"Thick, pulsing flows of glowing magma gushed out from numerous broad, flat volcanoes," geologist Paul Renne of the Berkeley Geochronology Center, who was not a part of this study said earlier in a statement. "Hundreds of cubic miles spread across Siberia-enough to cover the Earth to a depth of about 20 feet (6 meters)."

They noticed that the volcanic releases including the greenhouse gases -carbon dioxide and sulfur dioxide. The two together caused acidic rains that led to leaching of water soluble plant nutrient from the soil. This in turn damaged the plants and other vulnerable terrestrial species. Further, emission of methyl chloride-halogen bearing compounds- caused global ozone collapse.  The volcanic activity caused both acid rain and ozone depletion.

The team concluded, "The resulting drastic fluctuations in pH and ultraviolet radiation, combined with an overall temperature increase from greenhouse gas emissions, could have contributed to the end-Permian mass extinction on land."

The study was published in the journal Geology.