What happened when the asteroid that killed the dinosaurs collided with Earth?

represent nozzle ChicxulubHidden under the waters of the Gulf of Mexico, the site of an asteroid collision with Earth 66 million years ago, according to a Russia Today report.

The most significant consequence of this catastrophic event was the fifth mass extinction, which wiped out about 80% of all animal species, including the non-floating dinosaurs.

But what really happened when the asteroid hit Earth?

By studying geology in both Chicxulub And around the world, scientists have compiled what happened on that terrible day and the years after it.

Even before the asteroid collided, it was poised for doom, hitting Earth at its most devastating angle, according to a 2020 study published in the journal Science. Nature Communications. The asteroid was about 7.5 miles (12 km) in diameter and traveling about 27,000 miles per hour (43,000 km/h) when it created a 124-mile-wide (200 km) scar on the planet’s surface, said Sean Gulick, a research professor at the University of Texas Institute of Geophysics, who led the study.

More importantly, the asteroid hit the planet about 60 degrees above the horizon, and this angle was particularly devastating because it allowed the asteroid impact to eject a large amount of dust and aerosols into the atmosphere.

Gulick pointed to his colleague’s evidence in support of the cornering simulations, including the asymmetric structure of the crater, the position of the jagged (curved upwards) mantle rocks, unique sediment sequences in cores collected from the area, and, in particular, the lack of a distinct type of rock. , called evaporites, in the cores, such as halite and gypsum.

Gulick’s team estimated that the effect would have vaporized the evaporation rock, sending 325 gigatons of sulfur as sulfur mist, as well as 435 gigatons of carbon dioxide, into the atmosphere.

The material thrown into the atmosphere consists largely of crushed rock and sulfuric acid droplets, which came from sulfate-rich marine rocks, known as anhydrites, that evaporated during the asteroid impact, according to a 2014 study published in the journal Science. Nature Geoscience.

This cloud of microscopic material created a shroud around the planet, reducing the sun’s heat and incoming light, and the resulting long-term cooling changed the planet’s climate drastically.

A 2016 study in the journal . found Geophysical Research LettersThe average temperature in the tropics dropped from 81°F (27°C) to 41°F (5°C). As the incoming sunlight diminished, photosynthesis waned and the base of the food chain collapsed on land and in the ocean, bringing down the dinosaurs and many other animals.

The impact also caused massive tsunamis, which are shallow water waves that spread across Earth’s oceans. The wave initially reached nearly one mile (1.5 km) and traveled 89 mph (143 km/h), and other waves reached enormous heights, including up to 46 feet (15 meters) in the Atlantic Ocean and 13 feet (4 meters) in the North Pacific, according to modeling research.

Furthermore, depositional evidence from megawaves is preserved in the sediment record around Louisiana. A 3D seismic survey of the geology under Louisiana revealed huge long asymmetric ripples 52 feet (16 meters) high indicating the impact site in the bay.

Crushed rock and ash cascading to the surface after the impact also ignited a series of wildfires. The additional smoke and ash likely cooled the shroud, reducing incoming sunlight.

It is easy for geologists to see when the asteroid impacted when they examine the layers of rock; Through rocks around the world dating back to the end of the Cretaceous period 66 million years ago, there is a thin layer of clay enriched with iridium, a rare element on Earth but common among space rocks, according to a landmark 1980 study published in the journal Science. Science.

But while other amazing events, including wildfires and tsunamis, capture the imagination, Gulick thinks the bigger deal has been changes in Earth’s atmosphere, as horrific cover has led to cooling that lasted for more than a decade.

“The only way for a mass extinction event to happen is to mess with something that affects the entire planet,” he said.


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