Paleontologists have determined that the end-Permian extinction – the Earth’s most severe mass extinction that peaked about 252.3 million years ago – occurred over just 60,000 years, much faster than they previously believed.
Scientists say that long-lasting volcanic eruptions in a large region in Russia known as the Siberian Traps may have caused the end-Permian extinction – the most severe mass extinction in the history of life on our planet. This image shows the lava lake of the Nyiragongo Volcano, the Democratic Republic of the Congo. Image credit: Cai Tjeenk Willink / CC BY-SA 3.0.
About 96 percent of marine life and 70 percent of terrestrial life became extinct during what is known as the end-Permian extinction.
Many studies tried to explain the cause of this extinction, including an asteroid impact, massive volcanic eruptions, or a cataclysmic cascade of environmental events. But finding the cause requires better measurements of how long the extinction period lasted.
A 2011 study reported that the end-Permian extinction likely lasted less than 200,000 years. However, this timeframe still wasn’t precise enough to draw any conclusions about what caused it.
In a new study, paleontologists led by Massachusetts Institute of Technology scientist Dr Seth Burgess have revised previous estimates using more accurate dating techniques and found that the end-Permian extinction happened in just 60,000 years.
“We’ve got the extinction nailed in absolute time and duration. How do you kill 96 percent of everything that lived in the oceans in tens of thousands of years? It could be that an exceptional extinction requires an exceptional explanation,” said Prof Sam Bowring, also from Massachusetts Institute of Technology, who is a co-author of the paper published in the Proceedings of the National Academy of Sciences.
Prof Bowring with colleagues also found that, 10,000 years before the die-off, the oceans experienced a pulse of light carbon, which likely reflects a massive addition of carbon dioxide to the atmosphere.
This dramatic change may have led to widespread ocean acidification and increased sea temperatures by 10 degrees Celsius or more, killing the majority of sea life.
But what originally triggered the spike in carbon dioxide? The leading theory has to do with widespread, long-lasting volcanic eruptions from the Siberian Traps, a region of Russia whose steplike hills are a result of repeated eruptions of magma.
“It is clear that whatever triggered extinction must have acted very quickly, fast enough to destabilize the biosphere before the majority of plant and animal life had time to adapt in an effort to survive,” Dr Burgess, who is the lead author on the PNAS paper.
The new timeline adds weight to the Siberian Traps theory. “With such a short extinction timeline, it is possible that a single, catastrophic pulse of magmatic activity triggered an almost instantaneous collapse of all global ecosystems,” Prof Bowring said.
To confirm whether the Siberian Traps are indeed the extinction’s smoking gun, the team plans to determine an equally precise timeline for the Siberian Traps eruptions, and will compare it to the new extinction timeline to see where the two events overlap.
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Seth D. Burgess et al. High-precision timeline for Earth’s most severe extinction. PNAS, published online February 10, 2014; doi: 10.1073/pnas.1317692111
