Volcanoes May Have Caused Mass Extinctions?

Hugh Pickens writes "According to recent research, huge amounts of sulphur dioxide released by volcanic eruptions may have had more to do with wiping out dinosaurs than the meteorite strike at Chicxulub on Mexico's Yucatán Peninsula. Marine sediments drilled from the Chicxulub crater have revealed that that the mass extinctions occurred 300,000 years after Chicxulub hit Earth. The Deccan volcanism was a long cumulative process that released vast amounts of greenhouse gases into the atmosphere. '"On land it must have been 7-8 degrees warmer," says Princeton University paleontologist Gerta Keller. "The Chicxulub impact alone could not have caused the mass extinction, because this impact predates the mass extinction."' Keller also postulates a second larger and still unidentified meteor strike after Chicxulub, that left the famous extraterrestrial layer of iridium found in rocks worldwide and pushed earth's ecosystem over the brink. But where's the crater? "I wish I knew," says Keller."

Cause

[rossdee]

Maybe the meteor impact caused the volcanos to start up.

Re:Pre hoc ergo propter hoc?

[IdleTime]

Gerta Keller... *sigh*

I think everyone should take her research with quite a few grains of salt, she has been in a bitter fight for years over this issue and she has been quite obnoxious when it comes to the topic of Chicxulub and mass extinction. Until this is confirmed by independent research, nobody should take it for gold.

Re:Pre hoc ergo propter hoc?

[Black Copter Control]

It's like you shoot your friend in the back tonight, and (s)he dies in 2010. It's not that your friend no longer died after you fired the gun, but rather the 2-3 year wait kinda cancels the 'smoking gun' effect.

If, on the other hand, the prosecution produces evidence that you shot your friend in the head, and then your friend went into a coma for 2-3 years before dying, then they might still have good grounds for a murder charge.

Such a coma effect might be if we could show that the 300,000 years of increased vulcanism arose shortly after (and, thus, was probably caused by) the force of the Chicxulub impact.

Oh, and I'm of the opinion that the second impact near the main Chicxulub crater was simply a 'b' fragment of the larger asteroid...

Re:Ridiculous...

[gentlemen_loser]

And I'll keep telling it, and others like it until the groups who subscribe to such theories STOP pushing it on everyone else (ala school boards calling evolution into question, government policy decisions being based on it, etc.). I believe that such policies are dangerous as they are pushing our educational system backwards, thereby potentially triggering a landslide of bad side effects (intolerance, war, and damage to the economy, to name a few). You'll notice that I have never, nor will I ever, make an Amish (or other such group) joke. I politely disagree with their position, but fully recognize and respect their right to practice those beliefs. Its when those beliefs start being rammed down my throat that I take issue...

Re:I know where the crater is

[securityfolk]

I dunno - between 20W and 80W, and 55S to 65S (to the West of the Sandwich Islands), there are some bizarre ocean bed shapes (check http://maps.google.com/maps?ll=-59.739775,-46.557183&z=4&t=h&hl=en [google.com]). Looks like something - or maybe a couple of somethings smacked into Earth pretty hard. Looks like it hit hard enough to separate Antarctica from South America, or at least severely deform the mantle around that area. Does anyone have the scoop on what caused that region?

Re:I know where the crater is

[onion_joe]

Hmmm, that one is pretty interesting, especially the semi-circular concentric ridges in the bay.

However (of course, sorry) this http://maps.google.com/maps?ie=UTF8&ll=56.583692,-79.672852&spn=10.630137,27.597656&z=6&om=1 [google.com] also looks kinda funny, and there is no evidence of an impact site. Current theory is a standing wave pattern related to ocean currents and tides. No shocked quartz, no tektites. Bummer, because that is in my neck of the woods and I am a geo-nerd.

Only way to find out is to ground truth it. My wish list:

electron scanning microscope, some climbing rope, a sea kayak, probably some warm clothes, and some slaves, um, I mean grad students.