The methane bubbles act as a potent greenhouse gas, too, if they emerge all the way up and reach the surface, although the study said they seem to be consumed on the way up, with marine microbes converting the gas into carbon dioxide and producing conditions that are lower-oxygen and more acidic in the deeper offshore water. That is about equal to the amount released during the Deepwater Horizon blowout back in 2010.
Due to the cold temperatures and high pressure on the floor of the ocean, methane gas in the sediments form a crystal-like lattice structure with the water.
The downstream effects of this leaking methane aren’t entirely clear, though historically, methane has contributed to sudden and dramatic swings in the Earth’s climate. “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 Johnson, a UW professor of oceanography.
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.
In fact, methane is 23 times more powerful of a greenhouse gas than carbon dioxide.
Environmental changes in Washington and Oregon have started showing its effect on local biology and fisheries. As the ocean’s temperatures rise, methane frozen deep within the sea melts and releases.
Researchers last year observed a huge increase in methane plumes off the East Coast of the U.S. Until recently, these plumes were rare-sometimes only three were recorded in a year. 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.
Results show that methane gas is slowly released at nearly all depths along the Washington and Oregon coastal margin. 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.
Johnson said ocean water is being warmed at a depth of 500 meters, where many of these deposits lay.
The study was compiled from the work of research vessels from UW, earlier research and reports from fishermen. A new study said 168 bubble plumes had been detected in the past 10 years, a disproportionate number of which were found at a critical depth for methane hydrates’ stability. Results will confirm whether the gas originates from methane hydrates rather than from a few other source, such as the passive migration of methane from deeper reservoirs to the seafloor, which causes most of the other bubble plumes on the continental margin.
