Methane alters ocean floor

The following study was taken from sciencedaily website, it looks at the effects of methane on the ocean floor. The study appears in the journal Geophysical Research Letters.


MOSS LANDING, Calif., Feb. 7 (UPI) -- U.S. geologists say methane gas bubbling through seafloor sediments has created hundreds of low hills on the floor of the Arctic Ocean.
Monterey Bay Aquarium Research Institute geologists Charlies Paull, William Usser and colleagues say the origin of the ocean floor hills has puzzled scientists since the features were discovered in the 1940s.
The team collected sediment and gas samples from the underwater hills they call "pingo-like" features on the Beaufort Sea Shelf, off the north coast of Canada.
Pingos, small, dome-shaped, ice-cored hills, are found in many Arctic regions. Previous studies suggested pingo-like features are pingos that formed on land, but were submerged when sea level rose following the last ice age.
Paull and colleagues propose an alternative hypothesis: Pingo-like features form when methane hydrate -- a frozen mixture of gas and seawater -- decomposes beneath the seafloor, releasing gas that squeezes deep sediments onto the seafloor, much as toothpaste from a tube.
Since methane is a potent greenhouse gas, scientists would like to know how much comes from the seafloor worldwide. Future research on methane hydrates and pingo-like features may help address that question. Taken from: http://www.sciencedaily.com/upi/index.php?feed=Science&article=UPI-1-20070207-08032400-bc-us-oceanmethane.xml