The Newest Thing In Armageddons: The Verneshot

For some time now Canis Major and I have been playing a friendly game of "What's the Worst that Can Happen?", in which we argue about whether we should be more alarmed about, say, quantum vacuum decay, gamma ray bursts, supervolcanoes, global warming, the release of undersea methane hydrate, or what.

Well, in case you're jonesin' for a new super-worst-case scenario to worry about, check this out. It concerns the "Verneshot," a theoretical phenomenon which, if real, would explain some puzzling facts about mass extinctions. You're probably familiar with the dispute between those who think that the KT extinction (the one that killed the dinosaurs) was caused by a meteor impact and those who think that it was caused by an eruption of the Deccan Traps. The former hypothesis seems to have taken on the status of orthodoxy recently, but the question is complicated by the fact that the Deccan Traps were erupting around the time that the KT impactor hit.

Well, it turns out that this coincidence of "meteor" impacts and supervolcano-like eruptions may not be unusual. In fact, there is allegedly evidence of such coincidence of events for at least four mass extinctions. The odds of this occurring by chance are purportedly 1 in 3,500 (though intuitively they would seem to be even greater).

What allegedly happens during a Verneshot goes something like this: gas seeps up from deep in the Earth, as it is wont to do--but its escape is blocked by a big ol' chunk of ancient crust, a "craton." When enough gas builds up, there may be a supervolcano explosion at the edge--which would be bad enough--but even worse, the craton, along with a large amount of material from underneath it, is shot out of the atmosphere, only to come crashing back down on the other side of the Earth. And that means curtains for most living things on the planet. Even things lucky enough to avoid being vaporized, shredded, shot into orbit, squashed, or burned, would probably die in the resulting (non-nuclear) nuclear winter.

And get this: apparently the KT impactor hit at about a twenty degree angle, which is consistent with an impact by material ejected from the Deccan Traps. If true, the Verneshot hypothesis would unify these two competing explanations for the KT extinction.

Oh, and give us disaster afficianados a little something else to ponder...