![]() As Robertson and colleagues wrote in a paper titled “ Survival in the First Hours of the Cenozoic”: “For several hours following the Chicxulub impact, the entire Earth was bathed with intense infrared radiation from ballistically reentering ejecta.”Įarth became a world on fire. All of that energy was converted to heat as those spherules started to descend through the atmosphere 40 miles up, about 40 minutes after impact. “The kinetic energy carried by these spherules is colossal, about 20 million megatons total or about the energy of a one megaton hydrogen bomb at six kilometer intervals around the planet,” says University of Colorado geologist Doug Robertson. Geologists have found these bits, called spherules, in a 1/10-inch-thick layer all around the world. When the asteroid plowed into the Earth, tiny particles of rock and other debris were shot high into the air. The blast was enough to cause geologic disturbances, such as earthquakes and landslides, as far away as Argentina-which in turn created their own tsunamis.Īs dangerous as the waves were to life in the western hemisphere, however, the heat was worse. Not that the effects were limited to the area of impact. In the part of the world where the tsunami struck, these layers mark a violent boundary between the last day of the Cretaceous and the first of the following period, the Paleocene. What settled out is a geologic mess: ocean sand on what would have been dry land, and fossils of land plants in areas that should have been the ocean, in a mixed up slurry of ancient sediment. The impact struck with so much force and displaced so much water that within 10 hours an immense wave tore its way along to the coast. But the devil is in the geological details at places around the world, such as signs of a massive tsunami around the Gulf coast. The crater created by the impact is over 110 miles in diameter, a massive scar half covered by the Gulf of Mexico. The shock was a planet-scale version of a gunshot. Earth would never be the same again.īut what actually happened on the day the asteroid struck? By sifting through the rock record, experts are putting together a nightmarish vision of one of the worst days in the history of our planet. A chunk of extraterrestrial rock over 6 miles wide slammed into what would eventually become known as Mexico’s Yucatan Peninsula. Pterosaurs soared in the air, mosasaurs splashed in the seas, and tiny mammals scurried through the forest on what was just another day in the Late Cretaceous. Dinosaurs stalked each other and munched on lush greens as they had for over 170 million years. No one could have seen the catastrophe coming.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |