Methane Belch Caused First Mass Extinction 250 mya

[Richard W Travsky <rtravsky@uwyo.edu>]

 http://www.nature.com/nsu/030818/030818-16.html

 A massive methane explosion frothing out of the world's oceans 250
 million years ago caused the Earth's worst mass extinction, claims a US
 geologist. 

 Similar, smaller-scale events could have happened since, which might
 explain the Biblical flood, for example, suggests Gregory Ryskin of
 Northwestern University in Evanston, Illinois1. And they could happen
 again: "It's a very conjectural idea but it's too important to ignore,"
 says Ryskin.

 Up to 95% of Earth's marine species disapeared at the end of the Permian
 period. Some 70% of land species, including plants, insects and
 vertebrates, also perished. "It's arguably the single most important
 event in biology but there's no consensus as to what happened," says
 palaeontologist Andrew Knoll of Harvard University in Cambridge,
 Massacheusetts.

 Ryskin contends that methane from bacterial decay or from frozen methane
 hydrates in deep oceans began to be released. Under the enormous pressure
 from water above, the gas dissolved in the water at the bottom of the
 ocean and was trapped there as its concentration grew.

 Just one disturbance - a small meteorite impact or even a fast moving
 mammal - could then have brought the gas-saturated water closer to the
 surface. Here it would have bubbled out of solution under the reduced
 pressure. Thereafter the process would have been unstoppable: a huge
 overturning of the water layers would have released a vast belch of
 methane.

 The oceans could easily have contained enough methane to explode with a
 force about 10,000 times greater than the world's entire nuclear-weapons
 stockpile, Ryskin argues. "There would be mortality on a massive scale,"
 he says.
 ...
 Other sluggish seas might still be accumulating methane at their depths
 and could represent a future hazard, Ryskin adds. "Even if there's only a
 small probability that I am right, we should start looking for areas of
 the ocean where this might be happening," he argues.


Triggered by a meteor impact? um, what kind of traces could that
have left? Could this be involved in the impace that was supposed to
have happened to kill the dinosaurs?