A prolonged “volcanic winter” caused by millions of tons of ash launched into the Earth’s atmosphere likely contributed to the largest mass extinction event since the dinosaurs. Known as the End-Permian-Mass-Extinction event, or EMPE, which occurred about 250 million years ago, this nearly life ending catastrophe resulted in the permanent extinction of as much as 90% of Earth’s plant and animal species.
BACKGROUND: VOLCANIC WINTER AND EXTINCTION
As recently as 2018, researchers had mostly agreed that the EMPE was caused by a heating of the atmosphere resulting from massive lava floods, which at the time had spread across a huge area of the Russian province of Siberia known simply as the Siberian Traps. This warming, that previous research concluded, caused a wide range of environmental stresses, including a massive reduction in oxygenation of the world’s oceans, essentially suffocating nearly all marine life.
This critical environmental shift, which was caused by a release of carbon dioxide from those Siberian Traps, is still the most likely cause of much of the death in the EMPE. But now, researchers have shown that volcanic winters caused by contemporaneous eruptions probably compounded the Siberian Trap problem, further exacerbating an already critical environmental situation that likely led to even more extinctions.
ANALYSIS: SIGNS OF VOLCANIC WINTER IN THE ROCKS
Led by a team of researchers from the New York University Department of Biology, the latest study looked at minerals in the South China Sea that were from this EMPE time period. Specifically, the press release announcing the study notes, “they found mineral and related deposits on land in the south China region–notably copper and mercury–whose age coincided with the end-Permian mass extinction in non-marine localities.”
These deposits showed the effects of sulfur-rich emissions which the research team determined almost surely came from nearby volcanic eruptions. That’s because they were all covered with volcanic ash.
“Sulfuric acid atmospheric aerosols produced by the eruptions may have been the cause of rapid global cooling of several degrees, prior to the severe warming seen across the end-Permian mass-extinction interval,” said New York University Department of Biology Professor Michael Rampino, who is one of the authors of the paper.
“As we look closer at the geologic record at the time of the great extinction, we are finding that the end-Permian global environmental disaster may have had multiple causes among marine and non-marine species,” added Rampino.
OUTLOOK: NEXT SUPERVOLCANO MAY COME WITHOUT WARNING
Published in the journal Science Advances, over two dozen researchers participated in the study. This included the NYU team, a group from China’s Nanjing University Institute of Geology and Paleontology, the Guangzhou Institute of Chemistry, Montclair State University and the Smithsonian Institution’s National Museum of Natural History.