Deep sea trenches could combat climate change

Scientists found that underwater canyons trapped more carbon than previously thought.

Updated: Jan 18, 2011, 15:56 PM IST

London: Deep sea trenches could play a key role in climate change, path-breaking experiments suggest.

Probing the deepest part of the world`s oceans -- the Mariana Trench in the western Pacific, scientists found that such underwater canyons trapped more carbon than previously thought.

The carbon cycle has been studied in other parts of the ocean, such as the abyssal plain, the large flat area of the ocean between 4.6 km and 5.5 km deep, but that of deep sea trenches lying 11 km at the bottom has remained unknown until now.

According to the Daily Mail, Prof. Ronnie Glud, from the University of Southern Denmark and the Scottish Association for Marine Science (SAMS), said: "Although these trenches cover just two percent of the ocean, we thought they might be disproportionately important."

"It was likely that they would accumulate much more carbon because they would act as a trap, with more organic matter drifting to the bottom of them than in other parts of the ocean," Glud said, according to a statement by the university.

Prof. Glud explained that preliminary data from his team`s experiments suggested that trenches act as `traps.`

"Our results very strongly suggest that the trenches do act as sediment traps. And they also had high activity, meaning that more carbon is turned over by bacteria in the trenches than is turned over at 6,000 metre of depth in the abyssal plain," he said.

The international team, comprising scientists from the UK, Germany and Japan, used a lander to plumb the depths of the 10.9 km-deep trench with special sensors in a titanium cylinder.

It took three hours for the lander to fall to the seabed, where it carried out pre-programmed experiments.

Two explorers, Jacques Piccard and Don Walsh, previously reached the deepest part of the Mariana Trench, a point called the Challenger Deep in 1960, but no humans have gone back there since.