Scientists from McGill University in Montreal found that the cause of the death of dinosaurs was not only a meteorite that fell to Earth , but also massive volcanic eruptions that changed the climate on the planet.
Study author Professor Don Baker presented the results of his paper entitled “Recurring volcanic winters during the last Cretaceous: sulfur and fluorine reserves in Deccan lavas.” This work suggests a link between volcanic activity and the extinction of dinosaurs.
The Earth’s atmosphere 66 million years ago underwent toxic changes caused not only by an asteroid collision, but also by massive volcanic eruptions. Analysis of sulfur levels showed that before the asteroid impact, volcanic activity and mercury were already significantly influencing the planet’s climate.
Research by geologist Sarah Callegaro of the University of Oslo points to the formation of sulfur lava in Western India coinciding with climate change. The new data contradicts previous opinions and confirms that volcanism in the Deccan traps significantly influenced the climate before the disaster.
Although basalt in the region does not typically contain much sulfur, the slow release of the cooling molecule into the atmosphere after an eruption suggests a possible cause of the global drop in temperature. This resulted in periodic drops in temperature of up to 10°C followed by recoveries over the 100,000 years before the asteroid impact.
“Our research demonstrates that climatic conditions were almost certainly unstable, with repeated volcanic winters that could have lasted decades, prior to the extinction of the dinosaurs, ” explains McGill University geochemist Don Baker.
“This instability would have made life difficult for all plants and animals and set the stage for the dinosaur extinction event.”
The argument for pulses of eruptions does seem to be stacking up and volcanoes are, after all, what brought three quarters of all life on Earth to an end during the previous mass extinction.
“Deccan Traps volcanism set the stage for a global biotic crisis, repeatedly deteriorating environmental conditions by forcing recurring short volcanic winters,” the team concludes.
Their research was published in Science Advances.