Scientists have discovered an undersea deposit of frozen methane just off the Southern California coast, but whether it can be harnessed as a potential energy source is unknown. The size of the deposit is unknown but the researchers believe it to be substantial. In recent years, there has been a growing interest in tapping methane hydrates, ice-like crystals that form under seabeds and Arctic permafrost. Scientists estimate that the methane trapped in previously known frozen reservoirs around the globe could power the world for centuries. But finding the technology to mine such deposits has proved elusive. Methane hydrates, which resemble sugar crystals, form over hundreds of thousands of years when methane gas and water are at freezing temperatures and under intense pressure. The hydrates contain methane, the primary component of clean-burning natural gas, in a highly concentrated form. By some estimates, they contain twice was much carbon energy than all other fossil fuels combined. Although scientists say a new source of natural gas would provide a near-limitless energy source, some worry about the environmental effects of the gas. Gas hydrate deposits contain about three times the amount of methane currently in the atmosphere, and some scientists say an increase could lead to global warming and a significant change of the world’s climate.160Want local news?Sign up for the Localist and stay informed Something went wrong. Please try again.subscribeCongratulations! You’re all set! AD Quality Auto 360p 720p 1080p Top articles1/5READ MORESanta Anita opens winter meet Saturday with loaded card The newly discovered deposit is at the summit of a mud volcano 15 miles off the Southern California coast. Scientists were plumbing the Pacific Ocean on an unrelated expedition when they accidentally came across the volcano, which sits on top of an active fault zone in the Santa Monica Basin. To scientists’ surprise, the ecosystem surrounding the methane hydrate site was unlike any of the vast hydrate deposits around the world. Scientists found seashells and clams with unique characteristics, suggesting the area experiences an extreme flux of methane – gas mixing with water, said Jim Hein, a marine geologist at the U.S. Geological Survey in Menlo Park. Hein said it would probably be difficult to mine the hydrate deposit as an energy source because of its proximity to shipping lanes and to major cities, including Los Angeles. The giant twin ports of Los Angeles and Long Beach are nearby. The discovery was detailed in February’s issue of the journal Geology.