September 19, 2012/Kiel. Marine scientists from Kiel, together with colleagues from Bremen, Great Britain, Switzerland and Norway, spent four and a half weeks examining methane emanation from the sea bed off the coast of Spitsbergen with the German research vessel MARIA S. MERIAN. There they gained a very differentiated picture: Several of the gas outlets have been active for hundreds of years.
...

In fact, what the researchers found in the area offers a much more differentiated picture. Above all the fear that the gas emanation is a consequence of the current rising sea temperature does not seem to apply. At least some of the gas outlets have been active for longer. Carbonate deposits, which form when microorganisms convert the escaping methane, were found on the vents. “At numerous emergences we found deposits that might already be hundreds of years old. This estimation is indeed only based on the size of the samples and empirical values as to how fast such deposits grow. On any account, the methane sources must be older” says Professor Berndt. The exact age of the carbonates will be determined from samples in GEOMAR’s laboratories.