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Worst mass extinction in Earth's history left planet 'unbearably hot' and depleted ocean nutrients, preventing life from thriving for millions of years
- The Permian-Triassic extinction occurred roughly 252 million years ago
- The event wiped out 96 percent of sea life and 70 percent of life on land
- Researchers say it took between 5 and 9 million years for life to recover
- Warming ocean temps halted productivity at the bottom of the food chain
PUBLISHED: 20:38 GMT, 24 August 2016 | UPDATED: 00:28 GMT, 25 August 2016
It was the most catastrophic event in Earth’s history, wiping out the majority of species both on land and in the sea – and now, researcher have revealed new insight on the conditions that halted life for millions of years after ‘The Great Dying.’
In a new analysis at the Canadian High Arctic, a region that was once a margin of the supercontinent Pangaea, researchers discovered evidence of a significant nutrient gap following the Permian-Triassic extinction event.
This was likely caused by an extreme spike in ocean temperatures, which stalled productivity at the bottom of the food chain and delayed the recovery of ocean life.
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'The Great Dying' was the most catastrophic event in Earth’s history, wiping out the majority of species both on land and in the sea roughly 252 million years ago. It's thought that this event was triggered by volcanic eruptions
WHAT THEY FOUND
Researchers examined geological records in the Arctic to find out why ocean life took so long to bounce back.
The analysis revealed that the oceans were deprived of nutrients as a result of high temperatures, preventing algae production.
As these organisms are at the bottom of the food chain, ocean life could not thrive.
According to the researchers, the oceans didn’t begin cooling until 6-7 million years after the extinction, at which point the nutrients returned.
After the Permian-Triassic extinction roughly 252 million years ago, also known as ‘The Great Dying,’ it took between 5 and 9 million years for life to recover.
The event wiped out 96 percent of marine species, and 70 percent of life on land.
‘The mass extinction was likely triggered by an explosive event of volcanic eruptions in what is now Siberia,’ says Jochen Knies, a researcher at the Center for Arctic Gas Hydrate, Climate, and Environment (CAGE).
‘These eruptions lasted for a million years and emitted enormous amounts of volatiles, such as carbon dioxide and methane, which made our planet unbearably hot.’
In the study, published to the journal Geology, researchers examined geological records in the Arctic to find out why ocean life took so long to bounce back.
The analysis revealed that the oceans were deprived of nutrients as a result of high temperatures, preventing algae production.
As these organisms are at the bottom of the food chain, ocean life could not thrive.
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After the Permian-Triassic extinction roughly 252 million years ago, also known as ‘The Great Dying,’ it took between 5 and 9 million years for life to recover. The event wiped out 96 percent of marine species, including trilobites (pictured), and 70 percent of life on land
‘What used to be the northwestern continental margin of the supercontinent Pangea is now Canadian High Arctic,’ Knies says.
‘There we found evidence in geological records for a significant nutrient gap during this period. This means that global oceans were severely poor in nutrients such as nitrogen.
‘The high temperatures caused deepening of the thermocline and nutricline in the ocean so that upwelling of nutrients from the bottom to the surface of ocean ceased.
THE FIVE GREAT EXTINCTION EVENTS
Five times, a vast majority of the world's life has been snuffed out in what have been called mass extinctions.
End-Ordovician mass extinction
The first of the traditional big five extinction events, around 540 million years ago, was probably the second most severe. Virtually all life was in the sea at the time and around 85% of these species vanished.
Late Devonian mass extinction
About 375-359 million years ago, major environmental changes caused a drawn-out extinction event that wiped out major fish groups and stopped new coral reefs forming for 100 million years.
End-Permian mass extinction (the Great Dying)
The largest extinction event and the one that affected the Earth’s ecology most profoundly took place 252 million years ago. As much as 97% of species that leave a fossil record disappeared forever.
End-Triassic mass extinction
Dinosaurs first appeared in the Early Triassic, but large amphibians and mammal-like reptiles were the dominant land animals. The rapid mass extinction that occurred 201 million years ago changed that.
End-Cretaceous mass extinction
An asteroid slammed down on Earth 66 million years ago, and is often blamed for ending the reign of the dinosaurs.
‘With that the marine algae productivity was stalled.’
According to the researchers, the oceans didn’t begin cooling until 6-7 million years after the extinction, at which point the nutrients returned.
‘The boundaries that kept the nutrients from reaching the surface were weakened and the ocean waters were mixed,’ Knies says.
‘This caused the upwelling of nutrients, resuscitating the oceans, and leading to an explosion of life.
'The ecosystem voids created by the worst mass extinction in Earth’s history were finally filled.’
Not only does the study aim to answer questions about this ancient extinction, but the researchers say it also sheds light on the potential long-term effects on the oceans as global temperatures continue to rise.