Methane Leaks from the Ocean Floor: Not Such a Big Deal
It's not often that you hear the words "greenhouse gas" and "good news" juxtaposed in the same sentence. Aside from the occasional historical perspective on the beneficial role played by carbon dioxide in rendering our early planet inhabitable, the news concerning greenhouse gases has been - let's face it - rather glib. That makes every bit of good news - however little - something to look forward to.
A team of researchers from the University of California, Santa Barbara, has just made a discovery that could have significant implications for the buildup of methane gas in the Earth's atmosphere - and its impact on global warming. As we've mentioned before, methane deposits are found in large supply on the ocean floor; areas in which great quantities are emitted as bubbles - primarily from gas hydrates - are known as methane seeps.Scientists have long known that about half of the emitted gas dissolves into the ocean; its eventual fate, however, was heretofore unknown. Many were concerned that a significant portion of the gas managed to escape to the surface, contributing to atmospheric levels of methane and, thus, more GHG emissions. David Valentine, a professor in UCSB's Earth Science department, has determined that only about 1% of the dissolved methane escapes into the atmosphere - most of it taken up by the ocean.
"We found that the ocean has an amazing capacity to take up methane that is released into it – even when it is released into shallow water. Huge amounts of gas are coming up here, creating a giant gas plume. Until now, no one had measured the gas that dissolves and moves away, the plume," he explained.
Valentine and the study's lead author, Susan Mau, believe that a large percentage of the dissolve methane is oxidized by the activity of microbes. More wind, they found, caused more methane to be released to the atmosphere; at Coal Oil Point (COP), the location of their study (and one of the largest and best studied seep regions), the action of the currents moved most of the gas away from the seep area, into the path of oxidizing bacteria - which consume it.
While more research will need to be done here and at other large seep areas before too much can be taken away from this one study, it certainly provides a bit of good news - at a time when so little is otherwise readily available.