Warming Of Arctic

ScienceDaily (Aug. 16, 2009)The warming of an Arctic current over the last 30 years has triggered the release of methane, a potent greenhouse gas, from methane hydrate stored in the sediment beneath the seabed.
Methane released from gas hydrate in submarine sediments had been identifies in the past as an agent of climate change. The release of methane this way had been predicted.
The results say that the warming of the northward-flowing West Spitsbergen current 1° since the last thirty years caused the release of methane by breaking down methane hydrate in the sediment beneath the seabed.
Methane hydrate is an ice like substance composed of water and methane which is stable in conditions of high pressure and low temperature. At present, methane hydrate is stable at water depths greater than 400 metres in the ocean off Spitsbergen. But thirty years ago it was stable at water depths as shallow as 360 metres.
This was the first time that such behavior in response to climate change has been observed in the modern period.
Most of the methane currently released from the seabed is dissolved in the seawater before it reaches the atmosphere, methane seeps are episodic and unpredictable and periods of more vigorous outflow of methane into the atmosphere are possible. And methane dissolved in the seawater contributes to ocean acididfication.

Graham Westbrook Professor of Geophysics at the University of Birmingham, warns: "If this process becomes widespread along Arctic continental margins, tens of megatonnes of methane per year – equivalent to 5-10% of the total amount released globally by natural sources, could be released into the ocean."