The tsunami caused by a dinosaur-killing asteroid had mile-high waves that reached halfway around the world.
The asteroid that struck Earth approximately 66 million years ago caused a tsunami with mile-high waves.
According to a new study, the dinosaur-killing asteroid that slammed into Earth 66 million years ago also caused a jumbo-size tsunami with mile-high waves in the Gulf of Mexico, the waters of which traveled halfway around the world.
After analyzing cores from over 100 sites around the world and creating digital models of the monstrous waves after the asteroid’s impact in Mexico’s Yucatán Peninsula, researchers discovered evidence of this massive tsunami.
“This tsunami was strong enough to disturb and erode sediments in ocean basins halfway around the world,” said study lead author Molly Range, who conducted the modeling study for a master’s thesis at the University of Michigan’s Department of Earth and Environmental Sciences.
The research on the mile-high tsunami was previously presented at the annual meeting of the American Geophysical Union in 2019.
Range dove into the tsunami’s path immediately after the asteroid collided. Based on previous research, her team created a model of an asteroid that was 8.7 miles (14 kilometers) across and traveling at 27,000 mph (43,500 km/h), or 35 times the speed of sound, when it collided with Earth. Many lifeforms died as a result of the asteroid; nonavian dinosaurs became extinct (only birds, which are living dinosaurs, survive today), and roughly three-quarters of all plant and animal species were wiped out.

Four hours after the end-Cretaceous asteroid impact, the modeled tsunami sea-surface height perturbation (in meters).
Many of the asteroid’s negative effects are well known, such as igniting raging fires that cooked animals alive and pulverizing sulfur-rich rocks, which caused lethal acid rain and prolonged global cooling. Range and her colleagues studied the Earth’s geology to learn more about the resulting tsunami, successfully analyzing 120 “boundary sections,” or marine sediments laid down just before or after the mass extinction event that marked the end of the Cretaceous period.
According to Range, the boundary sections matched the predictions of their wave height and travel model.
The initial energy released by the impact tsunami was up to 30,000 times greater than the energy released by the December 2004 Indian Ocean earthquake tsunami, which killed over 230,000 people, according to the researchers.
When the asteroid collided with Earth, it left a 62-mile-wide (100-kilometer) crater and ejected a dense cloud of dust and soot into the atmosphere. According to the simulation, a curtain of ejected material pushed a wall of water outward just 2.5 minutes after the strike, briefly creating a 2.8-mile-tall (4.5-kilometer) wave that crashed down as the ejecta plummeted back to Earth.
At the 10-minute mark, a 0.93-mile-high (1.5-kilometer) tsunami wave swept through the gulf in all directions, about 137 miles (220 kilometers) away from the impact site. The tsunami had left the Gulf of Mexico and was rushing into the North Atlantic an hour after the impact. The tsunami passed through the Central American Seaway, which separated North and South America at the time, and into the Pacific four hours after the impact.
The waves had traveled through most of the Pacific and Atlantic oceans a full day after the asteroid collision, entering the Indian Ocean from both sides, and touching most of the world’s coastlines 48 hours after the strike.

The tsunami sea-surface height perturbation (in meters) predicted 24 hours after the dinosaur-killing asteroid collided with Earth.
The tsunami radiated primarily to the east and northeast, gushing into the North Atlantic Ocean, as well as to the southwest via the Central American Seaway, flowing into the South Pacific Ocean. Water moved so quickly in these areas that it most likely exceeded 0.4 mph (0.6 km/h), a velocity that can erode the fine-grained sediments on the seafloor.
According to the team’s models, other regions largely escaped the tsunami’s power, including the South Atlantic, North Pacific, Indian Ocean, and what is now the Mediterranean Sea. The water speeds in these areas were less than the 0.4 mph threshold, according to their simulations.

The maximum tsunami wave amplitude (in centimeters) caused by an asteroid impact 66 million years ago.
The team even discovered outcrops — or exposed rocky deposits — from the impact event on the north and south islands of eastern New Zealand, more than 7,500 miles (12,000 km) from the Chicxulub crater in Mexico. Initially, scientists assumed that these outcrops were caused by local tectonic activity. However, due to their age and location in the tsunami’s modeled path, the researchers attributed it to the asteroid’s massive waves.
“We believe these deposits are recording the effects of the impact tsunami,” Range said. “This is perhaps the most telling confirmation of the global significance of this event.”
While the models did not account for coastal flooding, they did show that open-ocean waves in the Gulf of Mexico would have exceeded 328 feet (100 meters), and waves would have reached heights of more than 32.8 feet (10 meters) as the tsunami approached the North Atlantic’s coastal regions and parts of South America’s Pacific coast, according to the statement.
Wave heights would have risen dramatically as the water became shallower near the coast.
According to the study’s authors, “depending on the geometries of the coast and the advancing waves, most coastal regions would be inundated and eroded to some extent.” “Any tsunamis documented in the past pale in comparison to such global impact.”
Source Credit: LiveScience.com
Image Credit: AGU Advances