Scientists at the University of California-Santa Cruz have found evidence that large methane reservoirs exist beneath the Antarctic ice sheet. According to a university report, the Antarctic Ice Sheet is likely a major a source of methane, a powerful greenhouse gas. Greenhouse gases absorb infrared radiation and keep the heat in the atmosphere.
Scientists believe that micro-organisms existing under oxygen-deprived conditions converted old organic matter beneath the Antarctic Ice Sheet to methane. Scientists are concerned that if the ice sheet shrinks, the methane could enter the atmosphere.
“It is easy to forget that before 35 million years ago, when the current period of Antarctic glaciations started, this continent was teeming with life,” said coauthor Slawek Tulaczyk, a professor of Earth and planetary sciences at UC Santa Cruz, in a statement.
“Some of the organic material produced by this life became trapped in sediments, which then were cut off from the rest of the world when the ice sheet grew. Our modeling shows that over millions of years, microbes may have turned this old organic carbon into methane.”
Scientists believe that 21,000 billion metric tons of old organic material lies beneath 50 percent of the West Antarctic Ice Sheet and 25 percent of the East Antarctic Ice Sheet.
“This is an immense amount of organic carbon, more than ten times the size of carbon stocks in northern permafrost regions,” said first author Jemma Wadham at the University of Bristol School of Geographical Sciences in a statement.
“Our laboratory experiments tell us that these sub-ice environments are also biologically active, meaning that this organic carbon is probably being metabolized to carbon dioxide and methane gas by microbes.”
The findings were revealed in a recent issue of the journal Nature.