New evidence suggests that volcanoes have caused the greatest mass extinction ever recorded

The researchers say that mercury buried in ancient rock is the strongest evidence to date that volcanoes have caused the largest mass extinction in the history of the Earth.

The extinction of 252 million years ago was so dramatic and widespread that scientists call it "the dying great." The disaster has killed more than 95% of life on Earth over hundreds of thousands of years.

Palaeontologists at the University of Cincinnati and the Chinese University of Geosciences said they discovered a mercury spike in the geological archives of nearly a dozen sites worldwide, convincingly proving that volcanic eruptions are at the origin of the global cataclysm.

The study was published this month in the journal Nature Communications.

The eruptions ignited vast coal deposits, releasing mercury vapor into the atmosphere. Eventually, it rained in marine sediments around the planet, creating an elemental signature of a disaster that would herald the dinosaurs' age.

"Volcanic activities, including volcanic gas emissions and the burning of organic matter, have released an abundant amount of mercury to the surface of the Earth," said senior author Jun Shen, associate professor at the University of California. China University of Geosciences.

Mass extinction has occurred to what scientists call the Permian-Triassic border. Mass extinction has killed much of the land and marine life before the rise of the dinosaurs. Some were prehistoric monsters in their own right, such as the ferocious gorgonopsids that looked like a cross between a saber-toothed tiger and a Komodo dragon.

The eruptions occurred in a volcanic system called the Siberian traps in present-day central Russia. Many eruptions did not occur in cone-shaped volcanoes, but in gaping soil cracks. The eruptions have been frequent and lasting and their fury has lasted hundreds of thousands of years.

"Generally, when you have large and explosive volcanic eruptions, a large amount of mercury is released into the atmosphere," said Thomas Algeo, a professor of geology at McMicken's faculty of arts and sciences. Columbia University.

"Mercury is a relatively new indicator for researchers and has become a hot topic for investigating volcanic influences on major events in the history of the Earth," said Algeo.

Researchers use the fossilized sharp teeth of lamprey-like creatures, called conodonts, to date the rock in which the mercury was deposited. Like most other creatures on the planet, disasters have decimated conodonts.

The eruptions propelled not less than 3 million cubic kilometers of ash into the air during this extended period. To put this in perspective, the eruption of Mount St. Helens in 1980 in Washington sent only 1 cubic kilometer of ash into the atmosphere, even though the ashes fell on windshields car as far as Oklahoma.

In fact, he said, the Siberian eruptions created a quantity of matter in the air, especially greenhouse gases, which warmed the planet by an average of 10 degrees Celsius.

Global warming would probably have been one of the main culprits for this massive extinction, he said. But the acid rain would have spoiled many water plans and raised the acidity of the world's oceans. And the warmer water would have had more dead zones because of a lack of dissolved oxygen.

"We are often left wondering what was the most harmful – creatures suited to cold environments would have been unlucky," said Algeo. "So, I guess the change in temperature would be the number one killer. The effects would be exacerbated by acidification and other toxins present in the environment."

Extending over an extended period of time, eruption after eruption, the Earth's food chain has not been restored.

"It's not necessarily the intensity but the time that counts," said Algeo. "The longer it lasted, the more the environment was under pressure."

Similarly, Earth has been slow to recover from the disaster as ongoing disturbances have continued to erode biodiversity, he said.

The Earth has witnessed five known mass extinctions over its 4.5 billion years.

Scientists have used another elemental signature – iridium – to pinpoint the probable cause of the global mass extinction that wiped out dinosaurs 65 million years ago. They believe that a huge meteor hit what is now Mexico.

The overheated plume of air thus blown into the atmosphere has resulted in a rain of iridium – containing material, which is found in geological records around the world.

Shen said the mercury signature provided compelling evidence that the eruptions of the Siberian traps were responsible for the disaster. Researchers are now trying to determine the extent of eruptions and what effects on the environment in particular have been most responsible for the mass mortality, especially for terrestrial animals and plants.

Shen said that the extinction of the Permian could enlighten us on how global warming could lead to the next mass extinction. If global warming was indeed responsible for the death of the Permian, what does warming mean for humans and wildlife nowadays?

"The release of carbon into the atmosphere by humans is similar to the situation of the upper Permian, where carbon abundance was released by Siberian eruptions," said Shen.

Algeo said that it was a source of concern.

"A majority of biologists think we are at the dawn of another massive extinction – the big sixth – I share that view too," said Algeo. "What we should learn is that it will be a serious matter that will hurt the human interest, so we must strive to minimize the damage."

People living in marginal environments such as arid deserts will suffer first. This will lead to more climate refugees around the world.

"We will probably see more hunger and massive migration in the hardest-hit areas – it's a global problem that we should recognize and proactively deal with." It's a lot easier to solve these problems before it happens. they do not experience a crisis. "