Santa Barbara Channel’s natural oil seeps are a beach-goer’s bane, flecking the shores with blobs of tar. But the leaking petroleum also creates fascinating geologic and biologic features. About 10 miles off the coast of Santa Barbara, several jet-black mounds interrupt the featureless sea floor. These asphalt volcanoes, virtually unique in the world, provide a rare habitat in a region known for its underwater biodiversity.
