Mendocino Ridge 4,600ft gas plume discovery off the California coast. Okeanos Explorer, "America's Ship for Ocean Exploration", is equipped with the latest in technology systems, including multibeam sonar. This technology involves sending beams of sonar to the ocean floor and measuring the amount of time it takes for those beams to bounce back to the ship. In doing so, the sonar creates a 3-D "sound picture", or map, of the seafloor. While the ship was testing its sonar off the coast of California, the sound waves bounced off gas in the water column, creating a remarkable image of a gas plume that rose 4,600 feet from the seafloor. A landslide area at the base of the plume has led some scientists to believe that the plume might be methane, released by the landslide from methane hydrates. Okeanos Explorer is preparing to explore the waters north of Indonesia in the summer of 2010, in collaboration with Indonesia. The ship will continue to explore the western Pacific in 2011. Video Credit: NOAA Office of Ocean Exploration and Research.