Mile-High Tsunami Caused by Dinosaur-Killing Asteroid Left Behind Huge “Megaripples” | Smart News
About 66 million years ago, a huge space rock the size of Manhattan crashed into Earth near the Yucatan Peninsula. The huge asteroid sent huge explosions of dust and waves across the planet and wiped out up to 75% of life, including dinosaurs.
Now scientists say they have found evidence of the resulting giant tsunami that submerged much of the Earth. In a study published in the journal Letters of Earth and Planetary Sciences, the researchers report how they discovered 52-foot-tall “mega-ipples” nearly a mile below the surface of what is now central Louisiana.
According to the paper:
“These mega-features have average wavelengths of 600 meters (1,968.5 feet) and average wave heights of 16 meters (nearly 52.5 feet), making them the largest documented ripples on Earth. . “
Led by Gary Kinsland, a geoscientist at the University of Louisiana, the research team found fossil records of the huge waves in the sediment 5,000 feet below the surface. They used seismic imagery data provided by oil and gas exploration companies to locate geological features.
Kinsland is convinced that these fossilized remains were left by the mega-ipples as they approached what was then the coastline. At the time, the area was about 200 feet below the ocean’s surface, he told Akila Raghavan of Scientific journal.
“The water was so deep that once the tsunami was over, the regular storm surges could no longer disturb what was there,” Kinsland explains.
Researchers found a series of mega-ipples spaced about half a mile apart preserved in the sediment, including shale formations, which settled at the site, reports geologist David Bressan in Forbes Magazine.
“Researchers argue that the mega-ipples are the result of a series of impact-induced tsunamis that swept through an ancient coastline. Thick layers of sand deposited by updrafts and countercurrents of tsunami waves formed symmetrical ripples on the seabed.
Kinsland and his colleagues chose central Louisiana as their research site because this is where they suspected the shoreline was 66 million years ago, at a time when water levels were high. higher. The dinosaur-killer asteroid has left an almost 100-mile-wide crater on the bottom of the Gulf of Mexico near the modern community of Chicxulub on the Yucatan Peninsula, reports Tessa Koumoundouros for Science Alert.
The researchers determined that the mega-ipples matched the crater in the Gulf of Mexico exactly. The circumferences of Louisiana’s geological features correspond to the impact site, Kinsland said in Raghavan.
The study builds on previous research on the impact of the asteroid near Chicxulub. In 2016, cores from a drilling expedition determined the formation of the crater. Two years ago, scientists located a fossil site in North Dakota that contained debris washed inland by the tsunami.
“We have little pieces of the puzzle that keep getting added,” Alfio Alessandro Chiarenza, paleontologist at the University of Vigo, told Raghavan. “Now this research is another, giving more evidence of a cataclysmic tsunami that likely flooded [everything] over thousands of kilometers.
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