Why Dinosaurs Are Extinct
Last week news reports from NASA stated that the earthquake in Chile had shifted the Earth’s axis by about three inches and thus shortened the length of the day. Nobody seems to be that concerned about losing 1.26 millionths of a second each day, but the domino effect of major natural events is nonetheless intriguing. I kept thinking about this as I read a recent report about the extinction of the dinosaurs (and as I think about species going extinct during our watch). Was it one small event that caused a chain reaction resulting in their demise, or something more catastrophic?
For decades experts have been split about the explanation, but on Thursday a panel of 41 scientists from around the world reviewed two decades worth of research in an attempt to confirm the cause. The new study, published in the journal Science, determined that a 9-mile wide asteroid crashed into Earth at Chicxulub (in what is now Mexico), traveling 45,000 mph and creating “one of the biggest holes the Earth has ever seen,” says study co-author Kirk Johnson of the Denver Museum of Nature & Science. The result? a series of events that ultimately proved fatal for over half the species of the planet.
“We now have great confidence that an asteroid was the cause of the KT [Cretaceous-Tertiary] extinction. This triggered large-scale fires, earthquakes measuring more than 10 on the Richter scale, and continental landslides, which created tsunamis,” said Joanna Morgan of Imperial College London, a co-author of the review.
Morgan said the “final nail in the coffin for the dinosaurs” came when blasted material flew into the atmosphere, shrouding the planet in darkness, causing a global winter and “killing off many species that couldn’t adapt to this hellish environment.”
Gareth Collins, another co-author from Imperial College, said the asteroid impact created a catastrophe that signaled the end of the 160-million-year reign of the dinosaurs. But on the bright side, it also turned out to be a great day for mammals. “The KT extinction was a pivotal moment in Earth’s history, which ultimately paved the way for humans to become the dominant species on Earth,” he wrote in a commentary on the study.
Yet in the meantime, many modern day species have become threatened, endangered, and extinct because of habitat loss, poaching, and climate change-related threats. Sometimes, it doesn’t take a 9-mile wide asteroid…
See the effects of the asteroid impact here.