The demise of dinosaurs wasn't solely orchestrated by a meteorite impact, as a recent study suggests. Published in Science Advances and co-authored by McGill University's Professor Don Baker, the research challenges the conventional narrative by proposing that massive volcanic eruptions, not just a celestial collision, triggered climate change that paved the way for dinosaur extinction.
The study focuses on the volcanic activity of the Deccan Traps, an expansive plateau in Western India sculpted by molten lava. Erupting an astonishing 1 million cubic kilometers of rock, these volcanic events may have significantly influenced the global climate approximately 65 million years ago.
The investigation led the research team on a global journey, involving on-site rock exploration in the Deccan Traps and subsequent sample analysis in locations spanning England and Sweden. This interdisciplinary approach sheds new light on the intricate interplay between volcanic activity, climate change, and the extinction of the ancient giants.
‘Volcanic winters': A new season?
In the laboratory, scientists embarked on estimating the quantities of sulfur and fluorine injected into the atmosphere during the 200,000 years preceding the dinosaur extinction due to massive volcanic eruptions.
Surprisingly, their analysis unveiled that the release of sulfur could have instigated a global temperature decline worldwide, creating what is known as a volcanic winter.
Professor Don Baker emphasized the significance of their findings, stating, “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. This instability would have made life difficult for all plants and animals and set the stage for the dinosaur extinction event. Thus, our work helps explain this significant extinction event that led to the rise of mammals and the evolution of our species.”
Decoding the ancient rock samples for clues presented a considerable challenge, and a novel technique developed at McGill played a pivotal role in unraveling the volcanic history.
Describing the technique for estimating sulfur and fluorine releases, Professor Baker drew a culinary analogy: “Imagine making pasta at home. You boil the water, add salt, and then the pasta. Some of the salt from the water goes into the pasta, but not much of it.” Similarly, certain elements become trapped in minerals post-volcanic eruption, and the new technique enabled scientists to measure sulfur and fluorine in rock samples, providing essential data to calculate the gases' release during eruptions.
The collaborative effort involved researchers from Italy, Norway, Sweden, the U.K., the United States, and Canada. Their discoveries represent a significant stride in unraveling Earth's ancient mysteries, offering insights that could inform our understanding of contemporary climate changes.
Source: McGill University