Well Now We Know'd Who'd Done it: Mass Exstinction Edition

Started by Inkidu, March 05, 2010, 07:21:31 PM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

Inkidu

http://news.yahoo.com/s/nm/20100304/sc_nm/us_dinosaurs_asteroid

Apparently it was a giant rock after all. I was really supportive of the little mammals eating the dino eggs but maybe that was just out of pride for the warm-bloods.
If you're searching the lines for a point, well you've probably missed it; there was never anything there in the first place.

Sabby

http://news.yahoo.com/s/nm/20100304/sc_nm/us_dinosaurs_asteroid

QuoteLONDON (Reuters) – A giant asteroid smashing into Earth is the only plausible explanation for the extinction of the dinosaurs, a global scientific team said on Thursday, hoping to settle a row that has divided experts for decades.

A panel of 41 scientists from across the world reviewed 20 years' worth of research to try to confirm the cause of the so-called Cretaceous-Tertiary (KT) extinction, which created a "hellish environment" around 65 million years ago and wiped out more than half of all species on the planet.

Scientific opinion was split over whether the extinction was caused by an asteroid or by volcanic activity in the Deccan Traps in what is now India, where there were a series of super volcanic eruptions that lasted around 1.5 million years.

The new study, conducted by scientists from Europe, the United States, Mexico, Canada and Japan and published in the journal Science, found that a 15-kilometre (9 miles) wide asteroid slamming into Earth at Chicxulub in what is now Mexico was the culprit.

"We now have great confidence that an asteroid was the cause of the KT 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.

The asteroid is thought to have hit Earth with a force a billion times more powerful than the atomic bomb at Hiroshima.

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."

Scientists working on the study analyzed the work of paleontologists, geochemists, climate modelers, geophysicists and sedimentologists who have been collecting evidence about the KT extinction over the last 20 years.

Geological records show the event that triggered the dinosaurs' demise rapidly destroyed marine and land ecosystems, they said, and the asteroid hit "is the only plausible explanation for this."

Peter Schulte of the University of Erlangen in Germany, a lead author on the study, said fossil records clearly show a mass extinction about 65.5 million years ago -- a time now known as the K-Pg boundary.

Despite evidence of active volcanism in India, marine and land ecosystems only showed minor changes in the 500,000 years before the K-Pg boundary, suggesting the extinction did not come earlier and was not prompted by eruptions.

The Deccan volcano theory is also thrown into doubt by models of atmospheric chemistry, the team said, which show the asteroid impact would have released much larger amounts of sulphur, dust and soot in a much shorter time than the volcanic eruptions could have, causing extreme darkening and cooling.

Gareth Collins, another co-author from Imperial College, said the asteroid impact created a "hellish day" that signaled the end of the 160-million-year reign of the dinosaurs, but 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.

(Collins has created a website at http://impact.ese.ic.ac.uk/ImpactEffects/Chicxulub.html which allows readers to see the effects of the asteroid impact.)

So... there were two main theories, one generally accepted to be the most likely by most of the world, and another that says volcanoes did it. Did we really need a big fuss kicked up to determine once and for all "Asteroid did it, case closed, kthxbai"

mannik

I've known that for years, and the scientists are just now figuring it out?

Vekseid

The Deccan Traps were one of the largest flood basalt events in Earth's history - of the 19 that have occurred, 11 are associated with mass extinctions.

Verifying that the Traps are not in fact responsible is somewhat pertinent as human activity resembles a flood basalt event.

mannik

Well...I'm a firm believer that humans are going to be the direct cause of the next great extinction event one way or the other. Whether it is nuclear, ecological collapse or something else entirely (like black holes made with that super collider doohicky in Europe) Simply proving that gassious emmissions weren't the culprit doesn't really mean much considering all that we are actually capable of.