Off the West Coast of the United States, methane gas is trapped in frozen layers below the seafloor. New research from the University of Washington shows that water at intermediate depths is warming enough to cause these carbon deposits to melt, releasing methane into the sediments and surrounding water.

Researchers found that water off the coast of Washington is gradually warming at a depth of 500 meters, about a third of a mile down. That is the same depth where methane transforms from a solid to a gas. The research suggests that ocean warming could be triggering the release of a powerful greenhouse gas.
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Submarine images have revealed that the Fukushima quake opened up cracks in the ocean floor as big as 6 feet wide. What effect this may have on future quakes in the area is unknown.

Coincidentally, shortly before the quake, researchers had taken photos of the same area of the seafloor where the crust would later rupture, leading to a tsunami that killed about 20,000 people. This meant that the seabed changes could be documented.

On the MSNBC website, Stephanie Pappas quotes seismologist Takeshi Tsuji as saying that his team of researchers saw open fissures in "many places," but how these cracks may effect future earthquakes along the same fault lines is unknown.
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