In one lake deep under Antarctica’s ice, microbes feast on ancient carbon
How microbes survive in lakes far beneath Antarctica’s ice sheet has been a mystery. Now scientists have figured out what’s on the menu for microbes in one buried lake in West Antarctica. The lake’s bacteria and other microbial inhabitants get by on carbon that seawater left behind thousands of years ago, researchers report in the April AGU Advances. The find adds to existing evidence that, during a period of warming about 6,000 years ago, the ice sheet in West Antarctica was smaller than it is today. That allowed seawater to deposit nutrients in what is now a lake bed buried under hundreds of meters of ice. This study is among the first to provide evidence from beneath the ice that the ice sheet was smaller in the not-so-distant past, geologically speaking, before growing back to its modern size, says Greg Balco, a geochemist at the Berkeley Geochronology Center in California. Understanding how the...