Posted on 10.08.2009 - 10:00 EDT in GENERAL NEWS by Rons_ROV_Links
By Sarah Douziech, Westerly News – Using a robot submarine, researchers want to figure out how methane hydrates are formed and how stable they are in changing ocean temperatures.
American scientists are studying ice-like structures deep on the ocean floor off Barkley Sound, south of Ucluelet, to find out why they're there and how they form.
About 12 scientists from the Monterey Bay Aquarium Research Institute (MBARI) in California are using a robot submarine to rove the sea floor around Barkley Canyon, several kilometres off shore, in search of methane hydrate formations that range in height and width from one to ten metres.
Kim Fulton-Bennett, a spokesperson for MBARI, said methane hydrates form on the sea floor with the combination of cold temperatures and high pressure.
"Methane is a natural gas that combines with the sea water to make these ice-like structures," Fulton-Bennett explained.
Every day scientists lower the Volkswagen bus-sized submarine called Doc Ricketts from their ship, the Western Flyer, into the water. Using cameras, light and robot arms, they are able to do experiments with the structures on the sea floor.
Scientists are interested in the methane hydrates for many reasons.
For one, Fulton-Bennett said, they'd like to know how the hydrates affect the shape of the sea floor.
"Sometimes they bulge up the mud and form domes," he said. "We don't really know why."
Another reason for the study is scientists have theorized that in the past millions of years, during other periods of climate change when the ocean warmed, the methane hydrates may have begun to dissolve.
"These hydrates are now in relatively stable ice-like form, but if they dissolve, the theory is, they will release all that methane into the atmosphere," Fulton-Bennett said.
He explained that methane acts like the greenhouse gas carbon dioxide, trapping sunlight in the Earth's atmosphere and causing it to warm faster.
"That's one theory of what could have caused warming in the past," he added. "There is some concern it could happen in the future, though it wouldn't be immediate."
Yet another reason why scientists are interested in the ice-like structures is that some people have suggested mining them or scraping them off the sea floor to use as a source of natural gas.
"That hasn't been proven to be economically feasible," Fulton-Bennett said, "and it would have an effect on the wildlife on the sea floor."
But probably most interesting to scientists is figuring out how the hydrates form in the first place.
"We want to know how they got there and in what conditions they are stable," Fulton-Bennett added.
Their research off the West Coast is part of a five-leg expedition totaling ten weeks where they will examine the composition of the sea floor, conduct research experiments on gas hydrates, look at the behaviour of carbon dioxide in the deep sea, underwater volcanoes and animals that live in the mid-water.
Only two weeks of the eight will be spent off the Canadian coast, Fulton-Bennett said, the rest will be spent further south in American waters.
The expedition is also being fully documented in an online blog, so people can follow what is happening on a day-to-day basis.
"People read about scientific stuff and it sounds kind of dry and boring and sort of abstract," Fulton-Bennett said.
He explained the blog is one way to make the study more concrete and for people to get to know the scientists and see what they do in real life.
"That's what makes an interesting story -- the frustrations, the successes," he said.