The day the Earth became liquid: what was the colossal impact that decimated the dinosaurs | Science and health

That's what American scientists say that were able to piece together every step of the colossal impact that decimated the dinosaurs.

Samples obtained from the crater formed after the collision concluded that the rocks had undergone a process of "fluidification".

In other words, the pulverized material began to behave like a substance similar to water.

Computer models allowed us to determine what would happen if a 12 km diameter rock object colliding with the Earth's surface collided with space.

Initially, a concave space of about 30 km in depth and 100 km in diameter would be created almost instantly.

The instability of the ground would later cause a collapse on the banks of the crater. And this collapse would in turn generate a rebound reaction from the bottom of the crater to heights greater than those of the Himalayas.

These gigantic movements would stabilize at any moment and there would only remain one crater of about 200 kilometers in diameter and one kilometer deep.

This crater is precisely the one that is now buried under a layer of sediment in the Gulf of Mexico, near the port of Chicxulub.

This model is called "crater dynamic cracking model" and the impact it describes is only possible if the rocks lose their strength for some time and flow without friction.

A new study, published in the scientific journal Nature, presents evidence of this process, based on rock drilling material from a peak ring located in the center of the Chicxulub Depression. Peak rings are typical formations of large impact craters, created by lifting the ground after collisions.

"What we discovered when looking at a rocky material, it's that it was fragmented," BBC researcher Ulrich Riller, a researcher at the University of Hamburg, told BBC .

"The rock was crushed and fragmented into tiny fragments first in millimeters, which gave rise to a fluid behavior which explains the flat base of the crater, which characterizes Chicxulub and other cases of major shocks, such as as we see it in Moon. "

Fluidization is not a process of melting rocks but fragmenting them by immense vibrational forces, says Sean Gulick of the l 39; University of Texas at Austin United States and one of the leaders of the drilling team.

"It is a pressure effect, a mechanical damage, the amount of energy that pbades through these rocks is equivalent to earthquakes of magnitude 10 or 11. It is estimated that the total impact had an energy equivalent to 10 billion Hiroshima. "

After their fragmentation and fluidification, the rocks have recovered their solidity to form the crater ring. This return to the solid state is visible in the samples obtained.

"This is manifested by discontinuities showing how the rocks slide relative to other rocks.These flat structures testify to the strength of the rock at the end of crater formation," said Riller .

Crater Chicxulub – the collision that changed life on Earth

• The asteroid 12 km in diameter dug a hole 100 km in diameter and 30 km deep in the earth's crust.
• Today, a large part of the crater is in the sea, under 600 m of sediment.
• In the past, the crater sank, leaving the crater 200 km in diameter
• . The center of the crater sank again, producing an internal ring. Earth, the crater is covered with limestone, but its edges are recognizable along an arc of cenotes – natural cavities in rocks dissolved by the pbadage of water and which have turned into tourist attractions.

& # 39; Not only in our solar system & # 39;

The research sheds new light on some of the most catastrophic days in the history of the Earth and on the mbadive extinction caused by the impact. It also contributes to the study of large craters in other planetary bodies.