About 252 million years ago, during the late Permian extinction, life on Earth came dangerously close to a fatal collapse. In the blink of an eye geological, almost every species on the planet disappeared.
The stage that we know as the ‘Great Death’ of 250 million years ago, wiped out almost 90% of living species was driven in part by an eruption that generated a global volcanic winter. This is the conclusion of new research led by the Chinese Academy of Sciences.
“By taking a closer look at the geological record at the time of the great extinction, we discovered that the global environmental disaster at the end of the Permian may have had multiple causes between marine and non-marine species ,” says Michael Rampino, professor in the New Department of Biology at the University of York and one of the authors of the article published in the journal Science Advances.
For decades, scientists have investigated what could have caused this global ecological catastrophe, with many pointing to the spread of vast lava floods along what is known as the Siberian Traps, a large region of volcanic rock in the Russian province. from Siberia.
The researchers examined contemporary copper-rich deposits from Sichuan province in southern China. They found mineral and related deposits on land in the southern China region, particularly copper and mercury, whose age coincided with the late Permian mass extinction in non-marine locations. The anomalies in these rocks, which were covered by layers of volcanic ash, suggest that they were formed or affected by sulfur-rich emissions from nearby volcanoes . Sulfur aerosols in the atmosphere act by reflecting incoming sunlight back into space and modifying clouds, resulting in a rapid cooling effect. The researchers believe that volcanism could have temporarily lowered the average global temperature by about 4 ° C , a change that added to the environmental effects resulting from other phenomena at the time.
These eruptions caused environmental stresses, including severe global warming from volcanic emissions of carbon dioxide and a related reduction in the oxygenation of ocean waters, resulting in the suffocation of marine life.
“There would have been global effects on the climate as the material from the eruptions would have been transported around the world by stratospheric winds,” experts say.
If this conclusion is correct, it suggests that the late Permian extinction could have been caused by the double whammy of geological activity. Thus, the Siberian trap eruptions were not the sole cause of the late Permian mass extinction, and the environmental effects of the eruptions in southern China and elsewhere could have played a vital role in the disappearance of dozens. of species.
Referencia: Hua Zhang, Feifei Zhang, Jiu-bin Chen, Douglas H. Erwin, Drew D. Syverson, Pei Ni, Michael Rampino, Zhe Chi, Yao-feng Cai, Lei Xiang, Wei-qiang Li, Sheng-Ao Liu, Ru-cheng Wang, Xiang-dong Wang, Zhuo Feng, Hou-min Li, Ting Zhang, Hong-ming Cai, Wang Zheng, Ying Cui, Xiang-kun Zhu, Zeng-qian Hou, Fu-yuan Wu, Yi-gang Xu, Noah Planavsky, Shu-zhong Shen. Felsic volcanism as a factor driving the end-Permian mass extinction. Science Advances, 2021; 7 (47) DOI: 10.1126/sciadv.abh1390
