The asteroid that wiped out most of the dinosaurs 65 million years ago sent a 1.6-kilometer-high tsunami that slammed into North America, a series of fossilized marks have confirmed. These wavy lines, buried within sediments in what is now central Louisiana, were discovered through seismic imaging by the University of Louisiana at Lafayette.
This cataclysmic impact on old Earth had extreme consequences, from dust engulfing the world to forest fires 1,500 kilometers from the impact site.
As the water was very deep in this area, the trace of the tsunami waves remained, covered with a thin layer of debris previously chemically linked to the crater of the asteroid in the Gulf of Mexico, near what is now the town of Chicxulub in the Yucatan Peninsula. The fossilized waves were spaced up to 1 kilometer apart and averaged 16 meters high. Scientists believe these waves represent the footprint of the tsunami waves as they approached the shore and disturbing the sediments on the seabed. This means that the wave’s footprint has remained for 66 million years, covered by a layer of falling air debris that has been linked to the asteroid’s crater.
Drawing a line from the crest of the waves led directly to Chicxulub crater
They found them by analyzing seismic image data obtained from a fossil fuel company operating in the region. They determined that the undulating ridges formed a straight line directly into the Chicxulub crater and their orientation is consistent with impact.
According to scientists, after this collision, huge tsunami waves swept across the world. The modeling of this monstrous tsunami suggests that its waves would have reached a staggering 1,500 meters high after the mega-earthquake triggered by the collision, which is more than 11 on the Richter scale. At that time, the entire land was covered in a cloud of dust. Thousands of kilometers around the place where this asteroid hit, there was enormous destruction. Due to this tsunami, dinosaurs and many other creatures, perished from this land forever, as they would have been dragged, marine life to land and terrestrial, to the sea and killing millions of creatures in the process.
“The tsunami continued for hours or days as it reflected several times within the Gulf of Mexico as it decreased in amplitude,” the authors wrote in the journal Earth and Planetary Science Letters.
While the dramatic waves would have caused devastation over thousands of kilometers, it was the global effects of atmospheric changes that altered the climate from the impact that wiped out so many species, abruptly ending the Mesozoic.
Experts hope to find other evidence of post-collision tsunami waves to help complete the puzzle of this major extinction event.
Referencia: Gary L. Kinsland, Kaare Egedahl, Martell Albert Strong, Robert Ivy, Chicxulub impact tsunami megaripples in the subsurface of Louisiana: Imaged in petroleum industry seismic data, Earth and Planetary Science Letters, Volume 570, 2021, 117063, ISSN 0012-821X, DOI: https://doi.org/10.1016/j.epsl.2021.117063.
