Seafloor "Bridges" Found to Span Earth's Deepest Trench
Crystal Gammon, OurAmazingPlanet Contributor
The Mariana Trench, located in the Pacific Ocean off the eastern coasts of Japan and the Philippines at a depth of around 6.8 miles (11 kilometers) below sea level is famous for being the deepest point on the planet's surface.
Now, to add to the Mariana Trench's fame, marine geophysicists recently mapped a set of surprising seafloor features nearby. At least four underwater "bridges" span the depths of the trench, where the Pacific Plate dives under the Philippine Plate.
"It wasn't common knowledge that these bridges occurred at all," said James Gardner, a marine geophysicist at the University of New Hampshire who found the structures. "This is really the first time they've been mapped in any detail."
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The result is an underwater "bridge" that stretches across the Mariana Trench. Gardner and a colleague found four of these structures, some rising as high as 6,600 feet (2,000 meters) above the trench and measuring up to 47 miles (75 km) long.
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http://www.livescience.com/17673-seafloor-bridges-span-deepest-ocean-trench.html