Home » An Asteroid that Killed Dinosaurs Caused a Tsunami that Ravaged the Bottom Thousands of Kilometers Away from the Point of Impact

An Asteroid that Killed Dinosaurs Caused a Tsunami that Ravaged the Bottom Thousands of Kilometers Away from the Point of Impact

by Coffee Table Science

 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.

Image credits : pixabay

The study, scheduled for online publication Oct. 4 in the journal AGU Advances, presents the first global simulation of the Chicxulub impact tsunami to be published in a peer-reviewed scientific journal. 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.

The Energy Impact of the Tsunami

“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 modelling study for a master’s thesis under U-M physical oceanographer and study co-author Brian Arabic and U-M paleoceanographer and study co-author Ted Moore.

“The distribution of the erosion and hiatuses that we observed in the uppermost cretaceous marine sediments are consistent with our model results, which gives us more confidence in the model predictions”, said Range, who started the project as an undergraduate in Arabic’s lab in the Department of Earth and Environmental Sciences.


Image credits : University of Michigan News

How strong was the tsunami?

The study authors calculated that the initial energy in the impact tsunami was up to 30,000 times larger than the energy in the December 2004 Indian Ocean earthquake tsunami, which killed more than 230,000 people and is one of the largest tsunamis in the modern record. 


The team’s simulations show that the impact tsunami radiated mainly to the east and northeast into the North Atlantic Ocean, and to the southwest through the Central American Seaway into the South Pacific Ocean. In some areas the underwater current speeds likely exceeded 20 centimeters per second.

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

For the current study, the researchers did not attempt to estimate the extent of coastal flooding caused by the tsunami. However, their models indicate that open-ocean wave heights in the Gulf of Mexico would have exceeded 100 metres, with wave heights of more than 10 metres as the tsunami approached North Atlantic coastal regions and parts of South America’s Pacific coast.

As the tsunami neared those shorelines and encountered shallow bottom waters, wave heights would have increased dramatically through a process called shoaling.

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