A Tyrannosaurus Wrecks #DeathByComet #DeathByVolcano @profmcateer

There is no doubt that a big rock from space hurtled through the Earth’s atmosphere at the same approximate time that the dinosaurs were eliminated from the species chain 65 million years ago. But despite this common knowledge, there is still an open question as to whether Dinosaurs were on the way out anyway, whether a new spurt of volcanic eruptions finally knocked them off, or whether really was a case of Death By Comet.

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New research published in Science suggest it may have been the perfect storm of all three of three reasons.

State shift in Deccan volcanism at the Cretaceous-Paleogene boundary, possibly induced by impact

As reported on EarthSky.org

A team of geologists have uncovered evidence that an asteroid impact on Earth 66 million years ago accelerated huge Indian volcanic eruptions – known as the Deccan Traps – for hundreds of thousands of years. The researchers suggest that, together, these planet-wide catastrophes led to the extinction of many land and marine animals, including the dinosaurs.

The researchers found that the eruptions accelerated within 50,000 years of the asteroid impact and were likely reignited by the impact, which may have generated magnitude 9 earthquakes or stronger everywhere on Earth.

For 35 years, paleontologists and geologists have debated the role that these two global events – the asteroid impact and the Deccan Traps eruptions – played in the last mass extinction. One side claims the eruptions were irrelevant, and the other side claims the impact was a blip in a long-term die-off.

The new evidence includes what the researcher say are the most accurate dates yet for the volcanic eruptions before and after the impact. The new dates show that the Deccan Traps lava flows, which at the time were erupting at a slower pace, doubled in output within 50,000 years of the asteroid or comet impact that is thought to have initiated the last mass extinction on Earth.

Both the impact and the volcanism would have blanketed the planet with dust and noxious fumes, say the scientists, drastically changing the climate and sending many species to an early grave.

Luckily for us humans, looks like the Dinosaurs never stood a chance.

How not to report science

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A lesson on how bad journalism is when it comes to science. The inference from this story is that natural causes caused a lot of warming back then, more than carbon-based emissions have today, and hence global warming is irrelevant. Of course a quick glance at the actual scientific paper shows that the journal article authors never made this claim. Yes, the ‘dinosaur methane’ did have the effect of warming the atmosphere. But it did so in a steady rate over 10s of millions of year. It didn’t suddenly jump up over 50 years. There is no reason to suspect the dinosaurs were not killed by the effects of an asteroid collision.

Death by asteroid!

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This is a great topic for astro101 classes. We can talk about reality compared to hollywood, about big numbers, big space, and how long odds can act up over long period of time. Two new articles add to the debate.

http://www.scientificamerican.com/podcast/episode.cfm?id=earth-was-longtime-asteroid-punchin-12-05-01

This first one shows that there has been far more asteroid collisions on Earth than previously accepted, seemingly mostly from one orbital location. Best to keep any eye on these ones then.

http://www.nytimes.com/2012/05/01/science/new-studies-of-permian-extinction-shed-light-on-the-great-dying.html?_r=1&ref=science

This second one talks about a species ending event long before the time of the dinosaurs. This one knocked off 95% of species on the Earth. This one was not an asteroid collision, instead a sudden release of CO2, probably from a volcano. The scary thing about this second one is the rise of CO2 in the last 60 years or so is paralleling this situation. Perhaps we should worry more about the risks we are doing to ourselves than about big bits of rock in space.