“The relative role of these two possible death mechanisms at the time and magnitude of extinction has been fiercely debated for decades,” the study said.
“We showed that only the asteroid’s impact, particularly with its prolonged consequences, was the true driver of the extinction,” said Alessandro Chiarenza, who conducted the research while studying for his doctorate in the department of earth sciences and engineering at Imperial College London.
“Could (volcanic activity) have played a smaller role in hindering the growth of dinosaurs before the asteroid hit? No, we show that Deccan Traps activity, if anything, might have cushioned the ‘negative effects’ of the impact on climate, which could fuel recovery after the extinction event. “
Dinosaur ecosystems
To determine whether it was the asteroid that hit the coast of Mexico or the volcanic activity that triggered climate-changing gases, the team combined geological climate markers and powerful mathematical models with information on what kinds of environmental factors, such as rain and temperature, every species of dinosaur needed to thrive.
The scientists were then able to map where these conditions would continue to exist after an asteroid attack or a period of massive volcanism. They found that the asteroid attack only wiped out all potential dinosaur habitats, while volcanism left some viable regions around the equator.
“Instead of just using the geological record to model the effect on climate that the asteroid or volcanism could have caused worldwide, we pushed this approach one step further, adding an ecological dimension to the study to reveal how these climate fluctuations affected seriously to ecosystems. ” Alex Farnsworth, a paleoclimatologist at the University of Bristol and co-author of the study, said in a statement.
“The impact of the asteroids would have created a climate too difficult for dinosaurs to survive, with globally icy temperatures for many years that would not allow vegetation to grow destabilizing the base of the food webs the dinosaurs were on,” he explained.
The asteroid attack would have released particles and gases into the atmosphere, blocking the sun for years and causing extreme cold. winters That made it impossible for almost all dinosaur species, except those that evolved into birds, to survive, according to the study.
“In one day, in the blink of an eye Geological eye, it’s all over for them, “Chiarenza said.
Rashes
There have been five mass extinction events on Earth, and volcanic activity is believed to have played a role in most of them.
The eruptions of the Deccan traps occurred over the course of tens of thousands of years, starting approximately 400,000 years before the mass extinction and continuing for approximately 500,000 years afterward, but the team said the cause of the extinction was unlikely.
In fact, the research team’s models suggested that volcanic activity might have played a role in helping life recover from the asteroid attack, restoring habitats, and helping new species that evolved after the asteroid attack survived.
Although volcanoes release gases and particles that can block the sun, they also release carbon dioxide, a greenhouse gas. In the long term, these particles and gases leave the atmosphere, while carbon dioxide accumulates and accumulates, heating the planet and increasing the survival and recovery of animals and plants that managed to overcome extinction.
“What surprised us most was that, contrary to popular theory, Deccan’s volcanism may well have been the benevolent hero of the time, trying to improve the effects of the so-called ‘nuclear winter’ caused by the impact of asteroids,” Farnsworth said.
“Unfortunately for the dinosaurs it couldn’t compensate enough for the cooling, but perhaps fortunately for us it might have been enough to allow mammals to inherit and eventually dominate Earth.”
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