Huge eruption almost sterilised the Earth in mass extinction event, study finds



Huge eruption almost sterilised the Earth in mass extinction event, study finds
By: Ritika shree
04 Oct 2017


A massive volcanic eruption in what is now known as Siberia sent the world spiralling into its worst extinction event, a new study has found.

The Great Permian Extinction, which occurred 252 million years ago, led to catastrophic environmental changes and wiped out as much as 96 percent of all species.

Lava flow from the massive volcanic eruption lasted for one million years, and released devastating amounts of greenhouse and sun-blocking gases.

Those chemicals triggered a dropping of the Earth's temperature.

Sun-blocking aerosols also stopped solar radiation reaching the Earth, which wreaked havoc on photosynthesis in the oceans and on land.

As a result, food chains crumbled and this in turn obliterated almost every living species on Earth.

The surviving four percent of living things allowed humans to evolve and stand where we are today.

Key to the findings of the study, which appears in journal Scientific Reports, was a global spike in the chemical element nickel at the time of extinction.

That nickel most likely came from huge volcanic eruptions in what is now Siberia.

These eruptions, researchers say, are associated with nickel-rich magmatic intrusions—rocks formed from the cooling of magma.

The rocks contain some of the greatest deposits of nickel ore on the planet.

Scientists documented anomalous peaks of nickel in regions ranging from the Arctic to India at the time of the Great Permian Extinction.

They found the nickel anomalies appeared to be a worldwide phenomenon.

The "nickel fingerprint" at the time of the extinctions convinced the scientists that it was the volcanic eruption in Siberia that produced intense global warming and the mass extinction event.

"The Siberian Trap eruptions were the catalyst for the most extensive extinction event Earth has ever endured," Sedelia Rodriguez, a co-author of the paper, said in a statement.

Rodriguez said the study would help scientists learn more about how events can trigger massive extinctions that affect both land and marine animals.















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