Microbe ‘cascade’ in Antarctic seafloor leads to discovery of methane leak, Energy News, ET EnergyWorld

Microbe 'cascade' in Antarctic seabed leads to discovery of methane leakBUENOS AIRES: Scientists have discovered an active methane seep from the Antarctic seafloor that could shed light on the powerful greenhouse gas trapped beneath the frozen continent.

Marine ecologist Andrew Thurber first spotted what a colleague described as a “microbial waterfall” while diving in the icy waters of the Ross Sea in 2012. What looked like a highway of white patches on the ocean floor were clusters of tiny organisms attracted to the leaking methane.

“My first thought was ‘wow’, and I was immediately won over by what that means for science,” said Thurber, an assistant professor at Oregon State University.

Scientists believe that a massive amount of methane is stored under the ocean floor in Antarctica. The discovery, published Wednesday in the journal Proceedings of the Royal Society B, marks the first time that a natural seep has been detected on the continent.

There is no evidence that climate change is the cause of methane seepage into Antarctica – good news for scientists concerned that global warming could cause permafrost to thaw and release methane for a long time. trapped inside.

However, if methane reaches the atmosphere, it could exacerbate global warming because methane is a more potent greenhouse gas than carbon dioxide. Atmospheric levels of methane have increased https://www.reuters.com/article/us-climate-change-methane/global-methane-emissions-rising-due-to-oil-and-gas-agriculture-studies-idUSKCN24F2X8 due to human activities, including agriculture and oil and gas drilling.

Thurber noted that microbes found near the Antarctic seep actually help prevent methane from entering the atmosphere by consuming the gas before it can rise through the water into the air.

This will not help mitigate human-made emissions, which account for at least half of the methane in the atmosphere. Oceanic sources of methane only contribute 1% of total global emissions.

Most of the research spent looking for natural underwater methane seeps has focused on depths of 200 to 600 meters, where the gas has to pass through “lots of microbial vents” before it can reach the atmosphere, said Thurber.

The Antarctic seep, however, was only 10 meters deep, putting the methane on a fast track to the surface.

“Ten meters is not 600 meters. This methane can enter the atmosphere and start to become a potential player in methane budgets,” Thurber said.

Another concern, Thurber said, is that microbes in cold, shallow waters took a long time to get to the Antarctic methane seep, a finding that could help scientists better understand microbial behavior and whether it could help prevent methane from seeping elsewhere into the atmosphere.

“We have to think of them as systems that don’t respond in a matter of days, an hour, or a month, but on a time-to-year scale,” Thurber said. “As the years add up, it becomes something that could potentially impact our ability to predict our future planet.”

Karla Heidelberg, a microbial ecologist with the US-based National Science Foundation, said more methane seeps could be revealed as climate change causes the oceans to warm and the Antarctic ice caps to melt.

“As the ice cover changes, this could expose more of these seeps to become potential inputs for atmospheric carbon,” Heidelberg said.

Antarctica’s frozen methane reserves could end up being a “tipping point” with massive warming potential if disrupted, said Ben Poulter, an environmental scientist at NASA’s Goddard Space Flight Center.

“If these become destabilized, you would have a massive surge of methane into the atmosphere which would cause more climate change,” Poulter said.

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