When an asteroid hit the Earth 66 million years ago, it not only ended the dinosaur era, but also caused huge waves that covered huge swathes of land around the globe.
The latest catastrophe came without warning: last Saturday, when the Anak Krakatau volcano erupted on the Sunda Strait between the Indonesian islands of Java and Sumatra, a submarine landslide unleashed a stir in the sea. The result was a nearly one meter high tsunami, which clashed a little later on the coasts of the surrounding islands.
At least 430 people were killed, nearly 1,500 others were injured. However, the concept of tsunami came into the consciousness of the world’s population 14 years ago: The “Christmas Tsunami” of 2004 was caused by the third strongest ever recorded earthquake in the Indian Ocean and cost the lives of about 230,000 people in 14 countries. Some of the resulting waves, which rolled over the coasts between Sri Lanka, India and Indonesia, were up to 30 meters high according to later investigations.
However, what fell over the world at the end of the Cretaceous overshadowed all these catastrophes: today on the northern edge of the Mexican peninsula Yucatán there is an approximately 200-kilometer-wide and ten-kilometer-deep dent in the earth’s crust, left behind 66 million years ago by a ten- to fifteen-kilometer-wide asteroid, which ultimately killed 70 percent of all species, including the dinosaurs.
The simulation below shows the immediate consequences of the Chicxulub impact.
Known today as Chicxulub crater, the structure is located in a region that was covered by a shallow sea at that time. This circumstance brought about tsunamis whose dimensions are beyond imagination: mountain-high waves raced across the Gulf of Mexico and spread over the primeval oceans. Even in the remotest parts of the world several meters high waves clashed against the coasts.
This apocalyptic scenario is the result of a recent study presented by a team led by Molly Range of the University of Michigan at the American Geophysical Union’s Washington, DC conference a few days ago. The paleoceanographer and her colleagues used two models to reconstruct the events of the day: one simulated the impact itself, assuming that a 14-kilometer-wide asteroid hit a shallow sea. With the second model, the researchers investigated the consequences of the displacement of water over the Cretaceous oceans. “It was necessary to use two different models,” said Brian Arbic, co-author of the study. “A conventional ocean model would not have reproduced the effect of such an asteroid impact correctly,” he added.
The result of their calculations was truly gigantic. Immediately after the impact, a wave of at least 1,500 meters high piled up, bursting over the nearest landmasses.
Global Impact of the Chicxulub Impact
A series of waves minutes later, the water sloshed back into the crater shaped by the impact. This rapid return triggered another series of massive waves that spread across the Atlantic and through the gap between North and South America into the Pacific Ocean. Range and her colleagues calculated that these tsunamis were at least 14 meters high at the open sea in the Pacific and Atlantic.
Near the coast, they probably piled up to much higher water levels. The researchers assume that such huge tsunamis must have also churned up the deep water, which should ultimately have had an impact on the then deep-sea sediments. Corresponding bores would therefore also require evidence for the simulations of the scientists to be ranked. The researchers are convinced that such future research will provide evidence that the Chicxulub impact actually caused tsunamis, one of the greatest of all time.