@hightor,
Quote: By refining the timeline of the dinosaurs' final days, the study reveals that their extinction was not a slow decline but an abrupt, catastrophic end to a flourishing era of life -- cut short by chance from beyond the sky.
That depends on which scientific school of thought that you wish to believe in, doesn't it.
Dust and debris blasted into the air by the impact is thought to have played a major role in ending the reign of the dinosaurs, blocking sunlight and stopping plants from growing and leading to wide starvation.
But the latest research shows that massive eruptions 200,000 years before that could have caused a volcanic ‘winter’ with plunging temperatures that would have severely weakened the dinosaurs’ grip.
And scientists were able to determine the volume of key particles released into the atmosphere after the eruptions thanks to a new technique of analysing rock samples likened to cooking pasta.
The study, published in the journal Science Advances, set out to estimate how much sulphur and fluorine was injected into the atmosphere due to the eruptions.
The researchers – from the US, UK, Sweden, Italy, Norway and Canada – remarkably discovered that the sulphur release could have triggered a drop in temperature around the world in a phenomenon known as a ‘volcanic winter’.
Don Baker, a professor in the Department of Earth and Planetary Sciences at Canada’s McGill University, said this would have likely ‘set the stage’ for the eventual extinction event of the devastating asteroid that wiped them off the planet.
The new research suggests that the asteroid impact, which also triggered a mega-earthquake that lasted as long as months, was just one part in the story of the dinosaurs’ extinction.
Searching for missing pieces to the puzzle, the study team delved into the historic volcanic eruptions of the Deccan Traps – a vast and rugged plateau in Western India formed by molten lava.
The researchers found that the Traps erupted an astonishing one million cubic kilometres of rock, which may have played a key role in cooling the global climate around 65 million years ago.
‘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,’ study co-author Professor Baker explained.
‘This instability would have made life difficult for all plants and animals and set the stage for the dinosaur extinction event.
‘This scientific work helps to explain this significant extinction event that led to the rise of mammals and the evolution of our species.’
The researchers’ work took them all around the world, from hammering out rocks in the Deccan Traps to analysing the samples in England and Sweden.
The team at McGill University even developed a new technique, likened to boiling pasta, to decode the volcanic history of the rocks.
The pioneering technique for estimating ancient sulphur and fluorine releases involved a complex combination of chemistry and experiments, Professor Baker explained.
