Scientists have discovered bodies of tiny, ancient creatures preserved undisturbed for millennia in a kilometer-thick slab of ice deep in an Antarctic lake.
Tardigrades And Crustaceans Beneath The Icy Lake
Researchers with the Subglacial Antarctic Lakes Scientific Access (SALSA) project found the remains during a mission to drill into the Mercer subglacial lake.
Scientists found the carcasses of the small animals, which ranged in size from 0.1 mm to 1.5 mm, after inspecting mud from an instrument lowered into the lake's icy waters. The mud contained remnants of algae that lived here millions of years ago, when Antarctica was much warmer.
Researchers also found a plant or fungus, a shrimp-like crustacean, and another shelled organism with delicate hairs.
"It hints that life may exist in more complex forms than thought previously underneath the massive ice sheet in Antarctica," Martin Siegert, head of the Lake Ellsworth Consortium, which aims to explore a subglacial lake under the ice of west Antarctica, commented on the discovery.
How Did The Ancient Creatures Get There?
Scientists do not know how the organisms came to be in the icy lake, but the creatures may have lived in nearby ponds and streams during warm periods, when the glaciers retreated 10,000 to 120,000 years ago.
They may have been washed into the lake through rivers under the ice. They may have also been transported into the lake after becoming stuck to a glacier.
The mission marks the third time scientists have explored an Antarctic subglacial cake. It is also the first time to access Lake Mercer, which spans 160 square kilometers in area, which covers twice the size of Manhattan,
The lake has only been previously explored with radar.
Scripps Institution of Oceanography glaciologist Helen Fricker discovered Lake Mercer by accident more than a decade ago while using satellite altimeter measurements to find the grounding line of a glacier.