“We see an unusually high number of bubble plumes at the depth where methane hydrate would decompose if seawater has warmed,” said lead author H. Paul Johnson,

“We see an unusually high number of bubble plumes at the depth where methane hydrate would decompose if seawater has warmed,” said lead author H. Paul Johnson, a University of Washington professor of oceanography. “So it is not likely to be just emitted from the sediments; this appears to be coming from the decomposition of methane that has been frozen for thousands of years.” Methane has contributed to sudden swings in Earth’s climate in the past. It is unknown what role it might contribute to contemporary climate change, although recent studies have reported warming-related methane emissions in Arctic permafrost and off the Atlantic coast.