“If the temperature of the oceans increases by two degrees as suggested in some reports, it will accelerate the thawing to the extreme. A warming climate could lead to an explosive gas release from the shallow areas,” says PhD Alexei Portnov at Centre for Arctic Gas Hydrrate, Climate and Environment (CAGE) with the Arctic University of Norway in Tromsø.
Not far from the shores of the Yamal Peninsula is Gazprom planning for extensive drilling for more natural gas. Both the Leningradskoye- and Rusanovskoye fields are on the Western shelf of Yamal in the Kara Sea. In total, Gazprom plans to develop 20 offshore fields in the Kara Sea.
Portnov and his colleagues have recently published the results from studies done on the seafloor of the Kara Sea in the Russian Arctic. The results are scary reading: The West Yamal shelf is leaking at depths much shallower than previously believed.
Researcher PhD Alexei Portnov. (Photo: CAGE)
“Significant amount of gas is leaking at depths between 20 and 50 meters,” the paper reads.
“Terrestrial Arctic is always frozen, average ground temperatures are low in Siberia which maintains permafrost down to 600-800 meters ground depth. But the ocean is another matter. Bottom water temperature is usually close to or above zero. Theoretically, therefore, we could never have thick permafrost under the sea,” says Portnov “However, 20 000 years ago, during the last glacial maximum, the sea level dropped to minus 120 meters. It means that today´s shallow shelf area was land. It was Siberia. And Siberia was frozen. The permafrost on the ocean floor today was established in that period,” says Portnov.
It is the permafrost that keeps the methane gas in the sediments. With warmer climate and warmer water in Arctic Oceans the permafrost layer is melting. It is also the permafrost under the seabed that stabilizes gas hydrates, ice-structures that usually need high pressure and low temperatures to form.
“Gas hydrates normally form in water depths over 300 meters, because they depend on high pressure. But under permafrost the gas hydrate may stay stable even where the pressure is not that high, because of the constantly low temperatures,” explains Alexei Portnov.
Gas hydrates contain huge amount of methane gas. It is destabilization of these that is believed to have caused the huge sinkholes that appeared as out of nowhere on the Yamal Peninsula last summer.
The study has discovered that gas is released in an area of at least 7,500 m2, with gas flares extending up to 25 meters in the water column.
With a warmer climate, more permafrost will melt, and more methane gas will leak out. The fear is a “point of no return” where leakages of methane will continue to warm the climate even if all human-caused releases are stopped.
Methane is a potent greenhouse gas, 28 times more powerful than CO2.
Under, you can see a video where scientits are climbing into the mysterious crater on the Yamal Peninsula.