About 66 million years ago, a massive asteroid crashed into Earth near the site of the small town of Chicxulub in what is now Mexico. The impact eradicated roughly 75% of the animal and plant species on Earth, including whole groups like non-avian dinosaurs and ammonites. Fine silicate dust from pulverized rock generated by the impact played a dominant role in global climate cooling and the disruption of photosynthesis following the event, according to new research.
The Chicxulub impact has long been thought to have triggered a global winter 66 million years ago, which led to the demise of the dinosaurs and around 75% of species on Earth.
However, what effect the various types of debris ejected from the crater had on the climate is debated, and exactly what caused the mass extinction remains unclear.
Previous research has suggested that sulfur released during the impact and soot from post-impact wildfires constituted the main drivers of an impact winter, but the size of silicate dust particles ejected into the atmosphere has not been considered to be a major contributor.
“The Chicxulub asteroid impact event 66 million years ago showcases a unique opportunity to examine the rate, magnitude and mechanisms of extreme and abrupt climate change in Earth’s history,” said Dr. Cem Berk Senel, a researcher at the Royal Observatory of Belgium and Vrije Universiteit Brussel, and his colleagues.
“The 45-60° inclined impact of a 10- to 15-km-sized carbonaceous chondrite on the Yucatán Peninsula in Mexico triggered a chain reaction of events ultimately responsible for the end-Cretaceous mass extinction and the demise of 75% of species, including the iconic non-avian dinosaurs.”
“Yet the climatic consequences of the various debris injected into the atmosphere following the Chicxulub impact remain unclear, and the exact killing mechanisms of the mass extinction remain poorly constrained.”
To evaluate the roles of sulfur, soot and silicate dust on the…
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