Dinosaur-killing asteroid triggered global tsunami, shows study

Maximum tsunami wave amplitude, in centimeters, following the asteroid impact 66 million years ago. Credit: Range et al. in AGU Advances, 2022.

The miles-wide asteroid that struck Earth 66 million years ago wiped out nearly all the dinosaurs and roughly three-quarters of the planet’s plant and animal species.

It also triggered a monstrous tsunami with mile-high waves that scoured the ocean floor thousands of miles from the impact site on Mexico’s Yucatan Peninsula, according to a new University of Michigan-led study.

The study, published in the journal AGU Advances, presents the first global simulation of the Chicxulub impact tsunami.

In addition, U-M researchers reviewed the geological record at more than 100 sites worldwide and found evidence that supports their models’ predictions about the tsunami’s path and power.

“This tsunami was strong enough to disturb and erode sediments in ocean basins halfway around the globe, leaving either a gap in the sedimentary records or a jumble of older sediments,” said lead author Molly Range, who conducted the modeling study for a master’s thesis under U-M physical oceanographer and study co-author Brian Arbic and U-M paleoceanographer and study co-author Ted Moore.

According to the team’s simulation:

One hour after impact, the tsunami had spread outside the Gulf of Mexico and into the North Atlantic.

Four hours after impact, the waves had passed through the Central American Seaway and into the Pacific.

Twenty-four hours after impact, the waves had crossed most of the Pacific from the east and most of the Atlantic from the west and entered the Indian Ocean from both sides.

By 48 hours after impact, significant tsunami waves had reached most of the world’s coastlines.