Methane Plumes Map (IMAGE) University of Washington Caption This map of Puget Sound shows the location of the methane plumes (yellow and white circles) detected along the ship’s path (purple). Black lines show the South Whidbey Island Fault Zone, the Seattle Fault Zone and the Tacoma Fault Zone. Black squares are urban sewer outfalls, which don’t match the bubble plumes’ locations. Credit Johnson et al./University of Washington Usage Restrictions With credit License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.