They chipped and then froze: this was the last day of the dinosaurs | Science Univision News

The impact it released so much sulfur into the atmosphere that it blocked sunlight and caused a global cooling that killed dinosaurs and with him 75% of life forms of the planet

It was a short-lived local hell, followed by a long period of global cooling: the dinosaurs "chipped and then froze", although "not everyone died that day," summarizes Sean Gulick, a research professor at the Geophysics Institute at the University of Texas and lead author of the research, which is based on the analysis of rock samples taken in 2016 from the "area zero "of the impact: the Chicxulub crater of the Yucatan Peninsula (Mexico).

The study, published in the newspaper Proceedings of the National Acedemy of Sciences, reconstructs the geological, chemical and biological processes generated by the impact of the asteroid that fell on Earth with a power equivalent to 10,000 million atomic bombs like Hiroshima's.

The analyzes indicate that most of the material that filled the crater in the hours after the impact originated in the same place of the impact or was dragged by the ocean water that flowed back to the crater from the surrounding Gulf of Mexico.

In a single day some were deposited 400 feet of material, a vertiginous accumulation rate that is among the highest ever found in the geological record and that has allowed reconstructing the events that took place inside and outside the crater from the moment of impact until several hours later.

Jens Ormö, a researcher at the Astrobiology Center and co-author of the study, analyzed the samples to try to determine how the accumulated material had been transported and deposited in the place of impact – and sometimes also its origin -, something essential to understand the amount of water that flowed in the crater and the processes that occurred when it was filling.

"Sediments reveal huge transport energies that are much larger than any other catastrophic flood known on the planet. Dense water full of debris moved with speeds that they were equivalent to the wind speed of hurricanes ", details Ormö.

But perhaps the most important research finding is related to sulfur, the chemical element that caused global cooling and the climate change that caused the mass extinction; "the real killer," according to Gulick.

Rock sample analysis reveals that the asteroid impact vaporized at least 325,000 million metric tons of sulfur-rich minerals present at the site of the impact, sufficient to make sunlight become dull and cause drastic cooling throughout the Earth.

The amount of sulfur that was released that day into the atmosphere is about 10,000 times higher than what the Indonesian volcano from Krakatoa expelled in 1883, which caused an average decrease of 2.2 degrees in global temperature for five years.

For Ormö, "everything that can be deduced from the sediments deposited in those first moments allows us to know how was the first day of the Cenozoic, the first day of a new era dominated by mammals and eventually by our own species. "