In what may be the most dramatic mass extinction in Earth’s history, an asteroid impacted our planet 66 million years ago near what is now Chicxulub on the Yucatan Peninsula. The resulting hellscape extinguished 75 percent of then living species – including all non-avian dinosaurs. Over the last few years, scientists have discovered many more traces of this cataclysmic impact, providing us with ever greater details of its extreme aftermath – from world-encircling dust to wildfires up to 1,500 kilometers (930 miles) from the impact site. In 2019, a team found fossil records of the immediate hours after, including evidence of debris swept up by the resulting tsunami.
Now, researchers have discovered enormous megaripples engraved by the tsunami in sediments 1,500 meters (5,000 feet) below what is now central Louisiana. By analyzing seismic imaging data for central Louisiana, gained from a fossil fuel company., the team determined the imprinted ripple crests form a straight line right back to the Chicxulub crater and their orientation is consistent with the impact.
These megaripple features have average wavelengths of 600 meters and average wave heights of 16 meters making them the largest ripples documented on Earth. Compare that to the largest Camas Prairie megaripple at 289m x 17m. 
Modelling of this monstrous tsunami suggests its waves would have reached a staggering 1,500 meters high (nearly 1 mile) after the Richter scale 11 megaearthquake triggered by the collision. The aftereffects would have been particularly devastating in the regions surrounding the impact site, sweeping sea life onto land and land life into the sea. “Tsunami continued for hours to days as they reflected multiple times within the Gulf of Mexico while diminishing in amplitude,” the team wrote. What carved out the ripples we can still detect today were the forces from the massive walls of water smashing into the shallow shelf near the shores, and reflecting back towards their source.
Excerpted from: sciencealert.com/tsunami-megaripples-from-the-dinosaur-killing-asteroid-impact-discovered-in-louisiana
Read another article at: https://www.sciencetimes.com/articles/32252/20210713/dino-killer-space-rock-left-fossilized-megaripples-mile-high-giant.htm