Warming ocean may be triggering mega methane leaks off Northwest coast

SEATTLE — As the waters of the Pacific warm, methane that was trapped in crystalline form beneath the seabed is being released. And fast.

New modeling suggests that 4 million tons of this potent greenhouse gas have escaped since 1970 from the ocean depths off Washington’s coast.

“We calculate that methane equivalent in volume to the Deepwater Horizon oil spill is released every year off the Washington coast,” said Evan Solomon, a University of Washington assistant professor of oceanography and co-author of the new paper, which was published in the journal Geophysical Research Letters. The modeling does not indicate whether the rate of release has changed as temperatures warm, but it does strengthen the connection between ocean temperature and methane behavior.

Solomon and his colleagues first learned about the methane leaks when fishermen started sending them photographs of bubbles coming up out of the deep.

“They’re really low quality phone shots of their fish finders, but every single location they gave us was 100 percent accurate,” Solomon said.