Scientists have long debated how the dinosaurs vanished 66 million years ago. The dominant explanation blames a massive asteroid that struck the Yucatán Peninsula. But a team at Dartmouth College has a very different take.
They reached this conclusion by building a simulation that used real geological data to test more than 300,000 scenarios. They ran the model on roughly 128 processors across 512 cores. The system aimed to reproduce the fossil record for the million years before and after the extinction. The researchers fed the model geological and climate data from three deep-sea cores; each core contains fossils dating from about 67 to 65 million years ago, according to the Daily Mail.
The simulation indicates the final blow to dinosaurs came from toxic gases released by the Indian supervolcano called the Deccan Traps, which altered the climate hundreds of thousands of years before the asteroid impact. During roughly a million years of eruptions, the supervolcano released 10.4 trillion tons of carbon dioxide and 9.3 trillion tons of sulfur dioxide into Earth’s atmosphere, the team estimates.
Volcanic eruptions are known to trigger mass extinctions, but this study is the first independent estimate of volatile emissions based on evidence of environmental impact. Brenhin Keller, an assistant professor in Dartmouth’s Earth Sciences department, said the model calculated how much carbon dioxide and sulfur dioxide would be needed to drive climate change and disrupt the carbon cycle. At the end of each run, all processors compared their results, prompting the team to hypothesize dangerously high emissions of carbon dioxide and sulfur dioxide during the Cretaceous-Paleogene extinction event—emissions they attribute to the Deccan Traps.
Not all scientists accept the Dartmouth team’s conclusion. The researchers stress that their findings come from their computer model.
