Scientists have been worried by large numbers of methane bubble plumes off the coast of Oregon and Washington and fear that warming ocean waters may be causing this to happen. In a new study, which is to be published in Geochemistry, Geophysics, Geosystems, scientists have stated that they have observed more than 160 bubble plumes over the past decade.
"We see an unusually high number of bubble plumes at the depth where methane hydrate would decompose if seawater has warmed. 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," said lead author H. Paul Johnson, a University of Washington professor of oceanography, said in a press release.
Science has yet to discover the effects of this leaking methane. But scientific history has recorded instances when methane has contributed to sudden and dramatic swings in the Earth's climate.
"The results are consistent with the hypothesis that modern bottom-water warming is causing the limit of methane hydrate stability to move downslope, but it's not proof that the hydrate is dissociating," study co-author Evan Solomon opined, reports Gizomodo, which added that researchers have not yet confirmed that melting methane deposits are causing the plumes.
"Current environmental changes in Washington and Oregon are already impacting local biology and fisheries, and these changes would be amplified by the further release of methane," Johnson said, according to Science Daily. Fourteen of the 168 methane plumes were located at the "transition depth" on the seafloor near Washington and Oregon, Science Daily reports.
It is at this depth that frozen methane "ice" or hydrate decomposes because of warmer ocean temperatures. Johnson feels that the plumes are probably originating from decomposing frozen methane and not from the seafloor sediments.