Scientists have released images of a methane "fountain" found "violently boiling" beneath an Arctic sea in Siberia.
Photos taken on-board the Akademik Mstislav Keldysh research vessel in the East Siberian Sea show huge methane bubbles rising to the surface of the water. Usually, scientists sample the water with special plastic cones, but they ditched those in favor of buckets with a bigger capacity, according to a statement by Russia's Tomsk Polytechnic University.
The images were captured during a 35-day-long expedition in the seas of the Eastern Arctic, which launched from the city of Archangel in northwest Russia, on September 17, and involved an international team of scientists.
The fountain near Bennett Island in the northern part of the East Siberian Sea spanned an area of around five metres.
At the site, the sea was "violently boiling with methane bubbles," Sergey Nikiforov, a journalist and spokesperson for the Tomsk Politechnical University on-board the research vessel told The Siberian Times.
Nikiforov said the scientists were lucky to find the fountain. "It was a needle in a haystack chase, to find an exact place of a methane seep in dark sea waters, but we found it!"
"Just right off the Academician Keldysh scientists noticed a spot of emerald-coloured water, with gas rushing to surface in thousands of bubble threads," he said.
The pockets of gas were released as frozen ground, known as permafrost, thawed beneath the ocean. Researchers measured concentrations of methane in the area and found it was six to seven times higher than the global average. By sampling the water near the fountain, the scientists found levels of methane were nine times higher than the global average. This is a concerning sign for global warming.
Permafrost is the term used to describe ground which has been frozen for at least two years, but can be in this state for tens of thousands. The frozen soil is packed with organic materials that haven't decayed.
As the ice melts, the material is exposed, breaks down, and releases gas into the atmosphere in the form of the greenhouse gasses carbon dioxide and methane. Methane is more dangerous in terms of climate change than carbon dioxide, because it has 21 times more warming potential.
The result is a phenomenon known as a positive feedback loop: where global temperatures rise, the permafrost thaws faster, and more methane is released, causing more warming, and the cycle continues.
Expedition leader Igor Semiletov has visited the Arctic 45 times, but said in a statement earlier in October: "This is the most powerful gas fountain I've ever seen. "No one has ever recorded anything like this before."
The project is a collaboration between scientists from seven countries including Russia: the U.S., Sweden, Norway, Netherlands, Italy, and the U.K.
As well as documenting methane levels, the team also investigated the water and sediments on the Northern Sea Route. This lead them to find microplastics in the eastern Arctic ocean, thousands of miles away from where humans live.
Elena Kudryashova, rector of Northern Federal University, Arkhangelsk told The Siberian Times: "Another important subject of our research was study of various types of microplastic in the seas of the eastern Arctic.
"It is important to compare and analyze results of all expeditions because microplastic represents a serious threat to organisms and sea ecosystems as a whole," she said.