Methane in the Arctic
via yesterday’s Independent newspaper:
Shock as retreat of Arctic sea ice releases deadly greenhouse gas
Dramatic and unprecedented plumes of methane – a greenhouse gas 20 times more potent than carbon dioxide – have been seen bubbling to the surface of the Arctic Ocean by scientists undertaking an extensive survey of the region.
The scale and volume of the methane release has astonished the head of the Russian research team who has been surveying the seabed of the East Siberian Arctic Shelf off northern Russia for nearly 20 years.
In an exclusive interview with The Independent, Igor Semiletov, of the Far Eastern branch of the Russian Academy of Sciences, said that he has never before witnessed the scale and force of the methane being released from beneath the Arctic seabed.
“Earlier we found torch-like structures like this but they were only tens of metres in diameter. This is the first time that we’ve found continuous, powerful and impressive seeping structures, more than 1,000 metres in diameter. It’s amazing,” Dr Semiletov said. “I was most impressed by the sheer scale and high density of the plumes. Over a relatively small area we found more than 100, but over a wider area there should be thousands of them.”
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The Russians are a bit behind here as both American and Canadian studies have been in the public domain for years, some for decades.
Methane is considered to be an energy resource as well as a ‘greenhouse’ gas. The impact on the environment is poorly understood much like our local cows which put more pollution into the air here in York Region than do we humans who live here.
“Gas hydrates occur abundantly in nature, both in Arctic regions and in marine sediments. Gas hydrate is a crystalline solid consisting of gas molecules, usually methane, each surrounded by a cage of water molecules. It looks very much like water ice. Methane hydrate is stable in ocean floor sediments at water depths greater than 300 meters, and where it occurs, it is known to cement loose sediments in a surface layer several hundred meters thick.” (U.S. Geological Survey Marine and Coastal Geology Program)
Methane hydrate was once thought to occur only in deep space where temperatures are low and water ice is common. Today, however, significant deposits have been found under sediments on the ocean floors. Methane clathrates have even been found in deep Antarctic ice cores recording a history of atmospheric prescence dating back some 800,000 years.
There is at least twice as much carbon trapped in gas hydrates worldwide as there is carbon in all the Earth’s fossil fuels. Extraction of methane from hydrates could provide enormous energy and petroleum feedstock resources. Also, incalcuable amounts of conventional gas resources are trapped in ocean sediments beneath the layers of methane hydrates.
Methane Hydrates deposits have been under study for years by the U.S., Canada, Japan, India and now, apparently Russia. Commercial production and gas retrieval is not too far off. New technologies will be in place by 2020 and commercialization is anticipated within 20 years.
And it’s not just the Arctic. Large accumulatiuons of methane hydrates lie off the coasts of both North and South Carolina. It is estimated by USGS scientists that these areas contain more than 1,300 trillion cubic feet of methane gas. This would represent 70 times the gas consumption of the U.S. in 1989.
Some things happen naturally whether we like them or not. The mere volume of this gas is immense. The deposits are very rich and will make methane hydrates a major candidate for development as a much needed energy resource.
3,000 times the volume of methane in the atmosphere is bound in marine hydrates. It is known that methane is released by underwater landslides. A sea-level fall could warm the Earth. So too could methane released from gas hydrates in the Arctic. Any cooling trends could be counteracted just as any warming trends could be exacerbated. The degree to which any of this might occur is unknown and happily unmodelled to date. Like I said, some things happen naturally whether we like them or not.
Methane hydrates also seem to possess unique acoustic properties. Further studies will have significant implications in the use of sonar devices, seismic exploration and marine research.
The headlines may seem scary but methane hydrates and methane gas were here long before us and will be long after we’re gone. It’s a cycle but some things are natural. We may turn out to be no more than a blip in time. Methane will not.