A team of ecologists and microbiologists confirmed the existence of the first active methane leaks from the seabed off the coast of Antarctica, reported in the journal Proceedings of the Royal Society B. the Discovery was made during an expedition in McMurdo Strait, which is located in the Ross sea. The researchers also found that microbial community, which must curb the release of methane into the atmosphere, did not fully adapt to the new conditions.
Methane is one of the most dangerous greenhouse gases, which leads to heating of the atmosphere and affects climate change. He has a very high greenhouse activity (20 years, one kg of methane will warm the planet is 80 times stronger than a kilogram of carbon dioxide), and its influence on the overall warming of the planet reaches 10 percent.
About a quarter of the sea of methane on Earth is off the coast of Antarctica. It is believedthat it was the result of slow decomposition of ancient plants and marine organisms that lived there 55 million years ago during the Paleocene-Eocene thermal maximum, when the continent was dominated by a favorable climate. Over time, when temperatures in Antarctica began to fall, the remains of soil, plants and animals were buried under the ice, where organisms have reworked them and turned some of them into methane. Today the cold and pressure of the ice keeps the gas from entering the atmosphere, but as the heat of the planet, the methane can be released.
For the first time methane leak was seen in 2011. She came from a cinder cone near the volcanic Ross island, which is separated from the mainland by the Strait of Antarctica McMurdo station. Five years later, Andrew Thurber (Andrew R. Thurber) from the University of Oregon together with his colleagues went back there and finally came up with an article on the results of the expedition. The researchers collected samples of sediment and water, as well as established tools for measuring methane flux, which allowed to confirm the presence of leakage at a depth of 10 meters. The flow of methane was 3.1 ± 0.9 millimole per square meter per day. Reasons began to be released greenhouse gas, scientists are unknown, but they may not be linked with the warming, since water in the Ross sea was not yet hot.
However, microbiologists are concerned about the reaction of marine organisms. As demonstrated by past research, when methane starts to be released from the sea floor, absorbing his germs, such as bacteria of the family Methylococcaceae, move back and prevent greenhouse gas to penetrate the atmosphere. But this time, their reaction was not fast enough: the authors of the article found that the microbial community has not yet formed a sufficient filter to reduce the emission of methane. According to scientists, before the microorganisms are fully adapted to the new conditions, it may take 5-10 years.
Recently, scientists also showed on the example of the wetlands that climate change violates the natural methane emissions. If people do not reduce anthropogenic emissions of greenhouse gases, methane emission bogs will increase by 80 percent by the end of the century.