Science

Asteroid alert: Dinosaur-killing space rock INSTANTLY acidified the ocean – study


The dinosaurs’ reign on Earth was brought to an end 66 million years ago when a 10 kilometre wide asteroid came crashing into what is now Mexico. Experts are still learning about the fateful asteroid impact, and the latest study has found the oceans surrounding the Americas were instantly acidified. Scientists had suspected that pH levels had dropped in the ocean – meaning it was more acidic – in the ensuing millennia after the asteroid collision, but no one expected it to be so instantaneous.

By analysing the chemical composition of foraminifera – which are tiny plankton – fossils from before, during and after the asteroid impact, known as the K-Pg event, scientists from Yale University could see how the marine environment changed over time.

Following the K-Pg event, the experts saw a sudden rise in the acidity of the ocean, according to the report published in the Proceedings of the National Academy of Sciences.

Not only would the drop in pH levels wipe out many species straight away, it would have caused huge damage to the food chain and eco-system which would have taken millions of years to overcome.

Lead author Michael Henehan, a former Yale scientist who is now at GFZ German Research Centre for Geosciences in Potsdam, Germany, said: “For years, people suggested there would have been a decrease in ocean pH because the meteor impact hit sulphur-rich rocks and caused the raining-out of sulphuric acid, but until now no one had any direct evidence to show this happened.

“Our data speaks against a gradual deterioration in environmental conditions 66 million years ago.”

Senior author Pincelli Hull, assistant professor of geology and geophysics at Yale, said: “The ocean acidification we observe could easily have been the trigger for mass extinction in the marine realm.”

It is still subject to debate as to exactly how long the dinosaurs managed to survive after the initial impact.

Previous research from the University of Berkley, California, believes there is evidence to suggest non-avian dinosaurs survived around 30,000 years afterwards, and they eventually went extinct due to the 100,000 years of drastic climate change caused by the impact.

READ MORE: Asteroid warning: Why rock twice size of Burj Khalifa could end world

However, the dinosaurs’ loss was humanity’s gain.

With no large predators, small mammals which were comparable to rodents began to thrive, which eventually led to the evolution of humans millions of years down the line.

Alice Roberts, presenter of the hit BBC documentary The Day the Dinosaurs Died, said: “Chances are, if it wasn’t for that asteroid we wouldn’t be here today.”



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