However, once scientists realized an impact event in Mexico may have caused the extinction of dinosaurs 65 million years ago, they began to study how impact events may have affected the environment, altered Earth's climate, and decimated plants and animals throughout the world.
The impact event linked with the dinosaur's extinction was immense, producing a crater well over 100 kilometers in diameter. Smaller impact events like the one that produced Barringer Meteorite Crater are not as deadly, but can still produce devastating results. In a recent study, David Kring at the University of Arizona studied the types of plants and animals that existed at the time of impact and determined how they were affected by the blast.
The impact occurred about 50,000 years ago, when northern Arizona (and the rest of the world) was in the midst of an ice age. While northern Arizona is now an arid place, it was cooler and wetter at the time of the impact. Rather than desert scrub or grasslands, the terrain was covered with a forest. Rather than rattlesnakes and antelope, the terrain was populated with mammoths, mastodons, giant ground sloths, and bison.
When the impact occurred it produced an explosive blast equal to 20 to 40 million tons of TNT. This is more than 1000 times more explosive than the blasts which destroyed Hiroshima and Nagasaki in World War II. The explosion produced a shock wave and an airblast, which radiated across the landscape. The airblast produced winds that dwarf those produced by hurricanes. Within three kilometers from the impact, winds in excess of 2000 kilometers per hour scoured the ground. Virtually any plant or animal within that area was killed. The air blast flattened trees out to distances of about 20 kilometers and animals in the same area were either killed or injured so severely that they would be unable to feed or defend themselves.
The impact devastated the local population of plants and animals that existed in the area 50,000 years ago. But this impact event, unlike the impact event that terminated the age of dinosaurs, did not cause a mass extinction. Indeed, at the same time it killed a lot of plants and animals, it also provided a new habitat for other plants and animals. The newly formed bowl shaped depression was soon filled with water, producing a lake which provided a new home for freshwater vegetation and aquatic animals.
