Posted on October 28, 2018
"All these fossils occur in a layer not more than 10 cm thick," said paleontologist Ken Lacovara on the Chicxulub impact that ended the dinosaur era. "They died suddenly and were buried quickly, telling us that this is a geological time, days, weeks, maybe months, but that's not thousands of years, it's not hundreds of thousands of years Essentially an immediate event. "
Scientists drilled into the Chicxulub Crater, buried beneath the Yucatán Peninsula, stripping rocks from the Gulf of Mexico that were hit by an asteroid 66 million years ago, forming the niche that made the rise of Homo Sapiens possible. The 15 km wide asteroid could not have hit a worse place on earth. Scientists have put together a detailed picture of the minutes after the big impact.
It's hard to imagine billions of tons suddenly spinning around like a liquid, the BBC reports, but that's exactly what happened when the asteroid struck. The analysis of rocks drilled from the remaining crater in 2016 shows a process of fluidization in which powdered material literally begins to behave like water.
The impact description – scientists call it the dynamic collapse model of cratering – is only possible if the hammered stones lose their power and flow smoothly for a short time. And it's the proof of this process of fluidizing something called the "peak ring" – essentially a hillock circle in the middle of the remaining Chicxulub trough.
"What we found in the core was that the rock was fragmented, breaking into tiny bits that are initially millimeter-sized, and that basically causes this fluid-like behavior, which ends up producing the shallow crater floor, the chicxulub and all of these large impact structures, including those we see on the moon, "characterizes Prof. Ulrich Riller of the University of Hamburg. Germany.
That is not melted rocks; Rather, the rock fracture is interrupted by immense vibrational forces, says Prof. Sean Gulick, who is jointly headed by the University of Texas. "It's a pressure effect, it's mechanical damage, the amount of energy that moves through these rocks is equivalent to magnitude 10 or 11 earthquakes, and the estimate for the total impact is about 10 billion Hiroshima bombs."
Eventually, the rocks will regain their strength. They have to, if they are to build the ring of hills. This return of rigidity is again observed in the core samples.
The outer rim (white arch) of the crater lies below the Yucatan peninsula itself, but the inner summit ring is best reached from OffshoreA The 12 km wide object dug a hole in the earth's crust, 100 km wide and 30 km deep. This shell collapsed, leaving a crater 200 kilometers wide and a few kilometers deep. The center of the crater bounced off and collapsed again, creating an inner ring. Today, a large part of the crater is buried in the sea under 600 m of sedimentary rock. It is covered in limestone ashore, but its edge is marked by an arc of sinkholes.
"It manifests in what we call shear fractions – planar discontinuities where rocks can slip past each other," added Prof Riller. "We see these fractures overprinting the previously smashed rocks, which are evidence that the rock has regained strength toward the end of crater formation."
"We explain a fundamental process that is common to every one of us rocky body will occur, "says Prof. Gulick. "For the first time, we've got rocks that tell us how they've deformed to temporarily act like a liquid and eventually become like a stone again – without melting – everything happens through overlapping deformation mechanisms fundamental process reviving the planet, not just in our solar system, but presumably in all solar systems. "
Profs Riller and Gulick were part of Expedition Drill Project 364, which was launched in April / May 2016 under the patronage of the European Consortium for Ocean Research Drilling (ECORD) and the International Ocean Discovery Program (IODP).
"Here we come to the great irony of the story – because in the end, it was not the size of the asteroid, the explosive power, or even its global reach that wiped out the dinosaurs – that's where the impact came from," Ben Garrod said BBC documentary "The day the dinosaurs died"
Gerta Keller, a Princeton geologist, has mocked for decades because the fifth extinction is not one of Asteroids, but caused by a series of colossal volcanic eruptions, was Chicxulub event: "It's like being in a fairy tale:" A big stone from the sky hits the dinosaurs, and the boom goes down. "And it has all aspects of a really beautiful story, it just is not true."
The disaster has devoured them for the past 30 years: the destruction of three quarters of the Earth's species – including the dinosaurs – during the last one Earthquake of Our Earth, About 66 Million Years Earlier
Photo credits: Thanks to Louie Psihoyos, a Greek-American photographer and film director who has created a powerful documentary with enough incriminating material to convince everyone with a piece of humanity that we must do something to change our own habits and tastes to save our planet. Interview with Louie at Google Talks. Click here to watch the trailer for his important documentary on the sixth mass extinction, Racing Extinction.
The Daily Galaxy on BBC