More Methane Bubbles Up off Oregon and Washington Coasts

So while the new findings still have to be studied to determine any future impact on the Earth’s climate, it is known that much of the methane gas bubbling to the surface is gobbled up by marine microbes that turn it into CO2.

That’s about the same amount of methane from the 2010 Deepwater Horizon blowout. Methane deposits freeze due to combination of factors like the frigid temperatures and high pressure at the bottom of the ocean on the continental margin.

Methane has earlier been expected to cause big & sudden swings in the climate of the Earth. But the boom in their number may suggest that methane is now coming from dormant methane that was frozen for thousands of years.

The latest published paper in the journal Geochemistry, Geophysics, Geosystems stated tht close to 170 methane bubble plumes were monitored over the past decade, which regarded the figure as critical to the stability of frozen methane pockets.

Study’s lead researcher H. Paul Johnson, professor of oceanography, said, “What we’re seeing is possible confirmation of what we predicted from the water temperatures: Methane hydrate appears to be decomposing and releasing a lot of gas”. But that fuels oceanic acidification since the excess of carbon dioxide promotes a more acid environment in the sea along shoreline.

If methane bubbles rise all of the way to the surface, they enter the atmosphere and act as a powerful greenhouse gas. Of these, about 14 were located at the “transition depth” in the ocean; there, there were more plumes per unit area than on surrounding parts of the Washington and Oregon seafloor. Moreover, if methane continues to be released from frozen deposits, seafloor slopes may become destabilized since there is no frozen methane to keep them glued to one another. In a 2014 study, the ocean is warming at 0.3 miles depths because of warm water surfaced in a climate change-caused hotspot off Siberia and moved by ocean currents to the region.

But previous studies had also displayed that transition depths are warming off the Pacific Northwest coast.

Johnson said ocean water is being warmed at a depth of 500 meters, where many of these deposits lay.

In the worst case scenario, scientists predict that, with a steady warming of three degrees Celsius every 100 years, about 85 percent of the methane contained in the sea floor could be released into the water column.

At present, co-author and oceanography associate professor Evan Solomon is analyzing the chemical composition of bubble plume samples emitted at about 500 meters deep off the Washington coast, seeing whether the gas comes from methane hydrates instead of other sources. A large number of the plumes were observed at a depth considered to be “critical”, in the stability of methane hydrate.