Tuesday, August 14, 2007

Global Firestorm May Have Instantly Wiped Out Dinos

I always thought dinosaurs died a slow, miserable death over hundreds, if not thousands of years. Maybe some dust, kicked up by an asteroid, blocked out the sun and made food scarce. It would have been cold, too. So perhaps dinosaurs slowly starved to death, shivering in darkness to the bitter end. But after a bit of reading this morning, I’m learning dinosaurs may have been killed off in a matter of hours.

Whatever the specific details of the mass extinction, the predominant theory is that a massive asteroid impact triggered the slaughter. At the top of the list of suspects, a 6-mile-wide rock that slammed into the Yucatan Penninsula (in Mexico), leaving the Chicxulb crater, which is 62 miles accross.

After the impact is where things get, um, hazy. One possibility, suggested by a 2004 University of Colorado study, is an instant surge in global temperatures triggered by debris from the asteroid collision. This according to
a 2004 Space.com report. Said one researcher, "The kinetic energy of the ejected matter would have dissipated as heat in the upper atmosphere during re-entry, enough heat to make the normally blue sky turn red-hot for hours." The report isn’t specific on how hot it would have been, but experts say it would be, “the equivalent of a global oven set on broil.”

If that’s not dramatic enough for you, another theory is that “a global firestorm of methane gas triggered by an asteroid impact,” according to a 1999 Naval Research Laboratory study,
also reported by Space.com. In this scenario, the asteroid shook up the Earth’s crust, releasing pockets of methane under the seafloor and elsewhere around the globe. Lightning may have been the spark that ignited the gas and set off the global firestorm.

This notion of a firestorm that engulfed the planet is pretty fantastic. How much methane would that actually take? That’s not mentioned in the report. But my next question would be, could that much methane have existed?

Yet another possibility is that debris from the impact rained down as millions of small fireballs across the earth, causing massive wildfires. According to the geological record, there’s enough soot to suggest half of the world’s forests went up in smoke.

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I started pound360 to channel my obsession with vitamins, running and the five senses. Eventually, I got bored focusing on all that stuff, so I came back from a one month hiatus in May of 2007 (one year after launching Pound360) and broadened my mumblings here to include all science.