Reply #6: Methane prime suspect for greatest mass extinction [View All]

[Submariner]

"Well, boys and girls, this may be it."

You may be on to something


Methane prime suspect for greatest mass extinction

16:01 26 March 2002
NewScientist.com news service
Jeff Hecht

The release of massive clouds of methane from icy hydrates buried under shallow ocean floors is the leading suspect for the most devastating extinction in the fossil record, according to a new analysis.

Methane best matches the unusual carbon-isotope fingerprints found at the scene of the crime, says Robert Berner of Yale University in Connecticut, US, though it cannot explain atmospheric carbon dioxide levels at the time.

Berner says: "It's possible that you could have a combination" of effects causing the mass extinction that ended the Permian period, 250 million years ago. The event wiped out the vast majority of marine species and left Europe a near-desert.

Many theories have been proposed to explain the extinction, including a comet or asteroid impact. Other ideas focus on two unusual events at the end of the Permian - the eruptions of two million cubic kilometres of lava across Siberia and unusual stratification of the oceans.

Some have even suggested that the mass dying itself - shown by a sudden abundance of fungi spores at the boundary - could have itself had affected global carbon cycles. Yet solid support for any one theory has been lacking.

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http://www.newscientist.com/article/dn2088-methane-prime-suspect-for-greatest-mass-extinction.html