The venting is too deep for the methane to reach the surface, instead it appears to dissolve into CO2 according to Skarke.
“The discovery of widespread methane seepage on the northern U.S. Atlantic margin was indeed surprising,” lead author Adam Skarke of Mississippi State University wrote the Washington Post in an e-mail. “This is because [it] lacks the geological properties commonly known to be associated with widespread seafloor methane emissions.” It’s the first time, he said, that widespread leakage has been discovered in a non-Arctic location that’s both free of large gas reserve and substantial tectonic activity.
The paper, published Sunday in the scientific journal, Nature Geoscience, found that the vents, which are at depths from 800 to 2,000 feet, have a sprawling swath. They reach hundreds of miles from Cape Hatteras, N.C., to the Georges Bank southeast of Nantucket, Mass. “Widespread seepage hadn’t been expected,” the paper said.
The finding raises a number of questions. First on the list: Are there a lot more? The paper says the discovery suggests “tens of thousands” of similar vents could pockmark the ocean floor, emitting vast quantities of methane gas. He told the BBC that their number could be as high as 30,000.