Wednesday, August 29, 2012

Antarctic methane?

"Large volumes of methane - a potent greenhouse gas - could be locked beneath the ice-covered regions of Antarctica, according to a new study."

That sounded interesting. I was astonished to learn just how high energy costs are at the South Pole (high enough that we’re looking at whether SSD are cheaper overall than hard drives!), and immediately wondered if it was possible to harvest some of that methane.

The findings indicate that ancient deposits of organic matter may have been converted to methane by microbes under the ice.

Or in other words if the glaciers simply squashed the ancient green grass then its decay and subsequent transformation might produce clathrates or dissolved methane at the bottom. If the ice sheets scraped the land bare underneath (like the Canadian Shield), then there’s nothing much there.

So, is there anything under the sheets? They tried to look at the bottom of the sheets entering the ocean, and didn’t get very far—too much gravel and other clutter diluting the mix. So the paper is based on

Large sedimentary basins containing marine sequences up to 14 kilometres thick and an estimated 21,000 petagrams (1 Pg equals 10^15 g) of organic carbon are buried beneath the Antarctic Ice Sheet. No data exist for rates of methanogenesis in sub-Antarctic marine sediments. Here we present experimental data from other subglacial environments that demonstrate the potential for overridden organic matter beneath glacial systems to produce methane. We also numerically simulate the accumulation of methane in Antarctic sedimentary basins using an established one-dimensional hydrate model...

A cool idea, but coal mining would be a better bet.

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