The asteroid was so large that, even at the moment of impact, the top could have risen more than a mile above the cruising altitude of a 747. “In its almost instantaneous descent, it compressed the air below it so violently that “Briefly, the authority of mass extinction”, Peter Brannen describes the impact of the asteroid Chicxulub 66 million years ago that hit the Earth off the coast of Mexico at the end of the Cretaceous, creating an epic impact in winter and a momentous day and transitory for the history of life on Earth.
“The pressure of the atmosphere in front of the asteroid began to excavate the crater before it arrived,” geophysicist Mario Rebolledo, from the Yucatan Center for Scientific Research, told Brannen. So when the meteorite hit ground zero it was totally intact. It was so massive that the atmosphere didn’t even scratch it. It would have been a nice day a second and the world was already over for the next. When the asteroid collided with the earth, in the sky over which there should have been air, the rock had drilled a vacuum hole from outer space in the atmosphere. When the skies rushed to close this hole, huge volumes of earth were ejected into orbit and beyond, all in a second or two of impact. “
In a new study, a research team from Imperial College London, the University of Bristol and University College London have shown that the impact of asteroids created the conditions responsible for the disappearance of dinosaurs worldwide, challenging the claims of Researchers who have suggested that tens of thousands of years of large volcanic eruptions may have been the actual cause of the extinction event, which also killed nearly 75% of life on the planet.
“Heartbreaking Scene at Ground Zero” – The day the dinosaurs died
The researchers also show that massive volcanism could also have helped life recover from the long-term asteroid attack. Their results are published today in Proceedings of the National Academy of Sciences.
Lead researcher Dr. Alessandro Chiarenza, who did this work while studying for his doctorate at the Department of Earth Sciences and Engineering at Imperial, said: “We showed that the asteroid caused a winter shock for decades, and that these effects Environmental decimated dinosaur-friendly environments In contrast, the effects of the intense volcanic eruptions were not strong enough to substantially alter global ecosystems.
“Our study confirms, for the first time quantitatively, that the only plausible explanation for extinction is the impact of the winter that eradicated dinosaur habitats worldwide.”
The asteroid attack would have released particles and gases into the atmosphere, blocking the Sun for years and causing permanent winters. Volcanic eruptions also produce particles and gases with sun blocking effects, and around the time of the mass extinction there were tens of thousands of years of eruptions in the Deccan traps in present-day India.
“The last dinosaur”: “Impact of steroids or lava flows and deadly gases”
To determine which factor, the asteroid or volcanism, had the most power for climate change, researchers have traditionally used geological climate markers and powerful mathematical models. In the new document, the team combined these methods with information on what kinds of environmental factors, such as rain and temperature, each dinosaur species needed to thrive.
They were then able to map where these conditions would continue to exist in a world after an asteroid attack or massive volcanism. They discovered that only the asteroid destroyed 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. ” said study co-author Dr. Alex Farnsworth of the University of Bristol.
“In this study, we added a modeling approach to key geological and climatic data that shows the devastating effect of asteroid impact on global habitats. Essentially, it produces a blue screen of death for dinosaurs, “said study co-author Dr. Alex Farnsworth of the University of Bristol.
“Death of Mars”: a Pluto-sized asteroid ignited ancient climate change
Although volcanoes release gases and particles that block the sun, they also release carbon dioxide, a greenhouse gas. In the short term after an eruption, sunscreens have a greater effect, causing a “volcanic winter.” However, in the long term, these particles and gases fall from the atmosphere, while carbon dioxide remains and accumulates, heating the planet.
After the initial drastic global winter caused by the asteroid, the team’s model suggests that in the long term, volcanic warming could have helped restore many habitats, helping the new life that evolved after the disaster to prosper.
“We provide new evidence to suggest that volcanic eruptions occurring around the same time may have reduced the effects on the environment caused by the impact, particularly by accelerating the rise in temperatures after the impact of winter,” Chiarenza said. “This volcano-induced warming helped increase the survival and recovery of animals and plants that achieved extinction, and many groups expanded immediately afterward, including birds and mammals.”
The Daily Galaxy, Andy Johnson, via Imperial College of London
Image at top of page: Illustration by Fabio Manucci of an individual from Ankylosaurus magniventris, a large species of armored dinosaur, witnesses the impact of an asteroid that fell on the Yucatan peninsula 66 million years ago. Even his large size and thick armor did not protect his species from the violence of this cosmic disaster.
