EDINBURGH, Scotland, Jan. 17 (UPI) -- European scientists say they are probing the Marianas Trench in the western Pacific, the deepest spot in the world's oceans, for climatological clues.

The international team of researchers is using a submersible designed to withstand immense pressures to study the bottom of the 6.7-mile-deep underwater canyon, the BBC reported Monday.


Early results show ocean trenches are acting as carbon sinks, suggesting they are a bigger factor in regulating the Earth's chemistry and climate than previously thought, researchers say.

Lead researcher Ronnie Glud, from the University of Southern Denmark and the Scottish Association for Marine Science, said operating at pressures of more than 2 million pounds per square inch was challenging, but advances in technology had made it possible.

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"This is the first time we have been able to set down sophisticated instruments at these depths to measure how much carbon is buried there," he told BBC News.

A lander equipped with special sensors packed in a titanium cylinder able to resist the pressures was launched from a ship and took 3 hours to free-fall to the sea bottom, carrying out pre-programmed experiments before releasing its ballast and returning to the surface.

The experiments allowed scientists to assess the abundance of carbon at the bottom of the deep trenches.

"Although these trenches cover just 2 percent of the ocean, we thought they might be disproportionately important, because 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.

"What it means is that we have carbon storage going on in these trenches that is higher than we thought before, and this really means that we have a carbon dioxide sink in the deep ocean that wasn't recognized before."