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Asteroid that wiped out dinosaurs also triggered powerful global tsunami, study says



After some simulations, the study concludes that tsunamis reached most of the world’s coasts within 48 hours of the asteroid impact that wiped out the dinosaurs.

Sixty-six million years ago, an asteroid several kilometers wide crashed into Earth, wiping out nearly all dinosaurs and about three-quarters of their species. again, The impact also triggered a powerful global tsunami, according to new research. .

huge waves generated by The Chicxulub asteroid unleashed waves several kilometers long, devastating the ocean floor thousands of kilometers from the impact site. Yucatan Peninsula (Mexico).

That’s the main conclusion of a University of Michigan-led study published in the journal this Tuesday. Progress of AGU“This tsunami It was strong enough to disturb and erode sediment in ocean basins in about half the world “Molly Range, lead author, said.

The authors of the study believe that the energy of the giant waves caused by the Chicxulub It was up to 30,000 times larger than the most devastating tsunami ever recorded. Occurrence in Sumatra, Indonesia, December 2004 left more than 230,000 people in more than a dozen countries.

What places did the tsunami affect?

team simulation The shock tsunami moved east and northeast into the North Atlantic and southwest across the Central American Straits South Pacific (which separated North and South America).

In some areas adjacent to these basins, submarine current velocities exceeded 20 centimeters per second, sufficient to erode fine-grained seafloor sediments.

of The South Atlantic, North Pacific, Indian Ocean, and what is now the Mediterranean Sea were far more protected from the devastating effects of the tsunami. – According to the team’s simulations, flow velocities were less than 20 cm/s at those locations.

The authors contrasted their model with sediments from the geological record collected during scientific offshore drilling projects. The study now states that “the geological evidence undoubtedly strengthens the study.”

What happened after the asteroid hit?

In the second part of a study dedicated to modeling, Brandon Johnson of Purdue University recreated the impact, crater formation, and tsunami initiation during the first minutes of the event.

for it, A 14-kilometer-diameter asteroid traveling at 12 kilometers per second was simulated impacting a granite crust covered with thick sediments and shallow seawater. The impact created a 100-kilometer-wide crater and ejected a dense cloud of soot and dust into the atmosphere.

Two and a half minutes after impact, a curtain of ejected material pushes the wall of water outward, Waves 4.5 kilometers high were formed. .

Ten minutes after the bullet hit the Yucatán, 220 kilometers from the point of impact, Waves 1.5 kilometers high began sweeping the sea in all directions according to the simulation.

After 10 minutes, the simulation results were input into two tsunami propagation models. MOM6 (used to model deep-sea tsunamis) and MOST, models used by tsunami warning centers to track giant waves across the ocean.

Two days after impact, tsunami becomes global

“The big result here is that two global models with different formulations gave nearly identical results,” says Ted Moore, a paleooceanographer at UM and study co-author.

According to computer simulation, Within an hour of impact, the tsunami flowed out of the Gulf of Mexico into the North Atlantic Ocean. Within four hours, the wave crossed the Central American Strait and entered the Pacific Ocean. .

Within a day of impact, the wave crossed most of the Pacific to the east and most of the Atlantic to the west, entering the Indian Ocean on both sides.in the meantime The tsunami reached most of the world’s coastlines within 48 hours .

The researchers did not attempt to estimate the extent of coastal flooding caused by the tsunami for their study, but their model Wave heights in the open ocean of the Gulf of Mexico would have exceeded 100 meters This means that the wave height will exceed 10 meters as the global tsunami approaches the North Atlantic and Pacific coasts of South America.

Source: Biobiochile

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