Embers of Ancient Inferno Reveal Worst Extinction in Earth’s History : ScienceAlert

The link between the eruption and the most powerful extinction event the world has ever seen is getting stronger. A new analysis of mercury isotopes have provided evidence that 200,000 years ago, remote areas of the Southern Hemisphere were covered by debris from a Siberian volcanic eruption.

What followed was the Great Dying, also called the Permian-Triassic mass extinction event, where most of life was wiped out under an ash-filled sky.

Although it is clear how things ended – with the loss of more than 90 percent of marine species and more than 70 percent of land animals – our understanding of what the greatest event of How did the world of death still remain cloudy, despite the best efforts of geologists.

By combining chemical traces trapped in rocks and oceans, paleontologists are confident that a series of volcanic eruptions produced a signal of dramatic changes in the atmosphere. The world and the oceans that ended up suffocating the animals.

But a mass extinction event like the Great Dying also needs a solid case before scientists can definitively say what caused it, and when it happened. In fact, they are looking back about 252 million years.

In previous research, zinc and nickel have been used to link changes in ocean chemistry to volcanic eruptions and loss of marine life. But these elements are recycled on the Earth’s surface, unlike the isotopes of mercury which gives a more consistent view of the volcano.

Also, most studies of this mass extinction event have focused on areas from the Northern Hemisphere, making it difficult to understand the impact of the volcano beneath the Earth. This is important because mounting evidence suggests that the Great Dying was not a single fatal event, but multiple extinction events that occurred in waves spanning over a hundred thousand years.

So, climatologist Jun Shen of the China University of Geosciences and his colleagues began to notice. mercury isotopes in rocks in two areas of the Southern Hemisphere: the Karoo Basin in south-central Africa and the Sydney Basin on the east coast of Australia.

During the Great Extinction, the basins were united into a single continent called Pangaea, but now they are separated by about 10,000 kilometers (6,200 miles) and the Indian Ocean. In them, the researchers found almost identical patterns: mercury isotopes reached the end of the Permian.

This evidence – from areas that are still very far from the Siberian Mountains, large lava flows created by the volcanoes in question – suggest. mercury Researchers say it erupted from volcanoes in the Northern Hemisphere and swept around the world.

“It turns out that the emissions of the volcano mercury has a distinct isotopic composition of mercury that accumulated at the end of the destruction,” explains study author and University of Connecticut geologist Tracy Frank.

“By knowing the age of these deposits, we can confirm the timing of this great Siberian extinction and eruption.”

Their work is consistent with signals from sulfur isotopes consistent with the Great Dying, and builds on previous research that suggests mass extinctions began in the land up to 600,000 before sea life began to breathe.

Christopher Fielding, a paleontologist at the University of Connecticut, explains:

“It wasn’t just one very bad day on Earth, in other words, it took time to build up​​​​​​​and this feeds well into the new results because it suggests that the cause of the eruption that’s the volcano.”

Researchers believe that pinpointing the exact cause of the Great Depression is not easy. Ash compounds from volcanic eruptions in southern China also contributed to the carnage, in addition to Siberian fires.

So, try as we might to reconstruct the sequence of events leading up to Earth’s greatest extinction event, perhaps the most important message we should receive is the fragility of life on the violent planet that today is subject to. ‘a stress on many of the same climate changes: rising temperatures. and greenhouse gases.

Research published in Nature Communication.

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