The asteroid that wiped out the dinosaurs also caused a global tsunami

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According to new research, when a city-sized asteroid collided with Earth 66 million years ago, it wiped out dinosaurs and sent monstrous tsunami waves around the planet.

The asteroid, which is about 8.7 miles (14 kilometers) wide, left its impact crater about 62 miles (100 kilometers) near Mexico’s Yucatan Peninsula. In addition to ending the reign of the dinosaurs, the direct hit caused the mass extinction of 75% of the planet’s animal and plant life.

When the asteroid collided, it caused a chain of catastrophic events. fluctuations in global temperature; Columns of aerosols, soot and dust fill the air; The fires started when pieces of burning material exploded from the impact and re-entered the atmosphere and rained down. In 48 hours, tsunamis circled the globe and were thousands of times more active than modern earthquake-induced tsunamis.

Researchers set out to gain a better understanding of the tsunami and its prevalence through modeling. They found evidence to support their findings on the tsunami’s course and strength by studying 120 ocean sediment cores around the world. A detailed study of the results was published Tuesday in the journal The American Geophysical Union advances.

It is the first global simulation of a Chicxulub-induced tsunami to be published in a peer-reviewed scientific journal, according to the authors.

According to the study, the tsunami was powerful enough to create massive waves more than a mile high and clean the ocean floor thousands of kilometers from where the asteroid hit. It effectively removed the sediment record of what happened before the event, as well as during it.

said lead author Molly Ring, who began working at the firm as a freshman and completed her dissertation at the University of Michigan.

Researchers estimate that the tsunami was up to 30,000 times more active than the Indian Ocean tsunami on December 26, 2004, one of the largest recorded tsunamis that killed more than 230,000 people. The energy of the asteroid impact was at least 100,000 times greater than the Tonga volcano eruption earlier this year.

Brandon Johnson, co-author of the study and assistant professor at Purdue University, used a large computer program called the hydraulic code to simulate the first 10 minutes of the Chicxulub effect, including the formation of craters and the onset of the tsunami.

It included the size and speed of the asteroid, which is estimated to move at 26,843 miles per hour (43,200 kilometers per hour) when it hit the granite crust and shallow waters of the Yucatan Peninsula.

Less than three minutes later, rocks, sediment and other debris pushed a wall of water away from the impact, causing it to rise 4.5 kilometers, according to the simulation. This wave subsided when the explosive material fell to the ground.

But when the debris fell, it made even more chaotic waves.

Ten minutes after the collision, a nearly mile-high ring-shaped wave started across the ocean in all directions from a point located 137 miles (220 kilometers) from the collision.

These simulations were then inserted into two different global tsunami models, MOM6 and MOST. While MOM6 is used to model deep ocean tsunamis, MOST is part of the tsunami predictions at the National Oceanic and Atmospheric Administration’s tsunami warning centers.

Both models provided roughly the same results, creating a tsunami timeline for the research team.

An hour after the impact, the tsunami traveled out of the Gulf of Mexico into the North Atlantic. Four hours after the collision, the waves crossed the Central American sea route in the Pacific Ocean. The Central American route separated North and South America.

This graph shows the movement of sea level rise in a tsunami 24 hours after impact.

Within 24 hours, the waves entered the Indian Ocean from both sides after crossing the Pacific and Atlantic. Within 48 hours of impact, the large tsunami waves had reached most of the Earth’s shores.

The undersea current was strongest in the North Atlantic, Central America and South Pacific sea lanes, exceeding 0.4 mph (643 meters per hour), strong enough to blow sediment on the ocean floor.

Meanwhile, the Indian Ocean, the North Pacific, the South Atlantic and the Mediterranean have been sheltered from the worst of the tsunami, with fewer underwater currents.

The team analyzed information from 120 sediments that largely came from previous scientific ocean drilling projects. There were multiple layers of intact sediment in the waters protected from the wrath of the tsunami. Meanwhile, there were gaps in the sediment record for the North Atlantic and South Pacific oceans.

The researchers were surprised to find that sediments on the eastern coasts of New Zealand’s northern and southern islands were deeply disturbed by multiple cavities. At first, scientists believed this was due to plate tectonic activity.

But the new model shows that the sediment was directly in the path of the Chicxulub tsunami, despite being 7,500 miles (12,000 km) away.

“We believe these deposits record the effects of a tsunami impact, and this is perhaps the most significant confirmation of the global significance of this event,” said Ring.

Although the team did not estimate the impact of the tsunami on coastal flooding, the model shows that the coastal regions of the North Atlantic and Pacific coasts of South America were likely exposed to waves greater than 20 meters in height. The waves grew as they approached the shore, causing flooding and erosion.

According to Brian Arbeck, study co-author and University of Michigan physics professor, future research will model the extent of global flooding after an impact and to what extent the effects of a tsunami can be felt.

“Obviously, the biggest floods were closest to the impact site, but the waves are likely to be very large even further away,” Arbeck said.

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