Tuesday, August 18, 2009

Methane bubbles up by Arctic water warming


At the deep Arctic ocean the water is warming due to climate change. This causes mega tonnes of methane to bubble out beneath the sea floor.The methane is probably coming from reserves of methane hydrate beneath the sea bed. These hydrates, also known as clathrates, are water ice with methane molecules embedded in them.

The methane plumes were discovered by an expedition aboard the research ship James Clark Ross, led by Tim Minshull of the National Oceanography Centre, Southampton, in the UK.

The region where the team found the plumes is being warmed by the West Spitsbergen current, which has warmed by 1 °C over the past 30 years.

With the rise bigger bubbles can escape out to atmosphere and the smaller ones can get dissolve with the ocean water and can increase the acidic nature of water which could harm life adversely.

The methane being released from hydrate in the 600-square-kilometre area studied probably adds up to 27 kilotonnes a year, which suggests that the entire hydrate deposit around Svalbard could be releasing 20 megatonnes a year.

If methane began escaping at similar rates throughout the Arctic, it would dramatically increase methane levels in the atmosphere.

Globally, it's thought that around 500 to 600 megatonnes of methane are released into the atmosphere each year.

Methane hydrate could be used as a new, somewhat greener fossil fuel, but extracting the methane without releasing any into the atmosphere remains a challenge.

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