These are exciting times to study Antarctica and zero in on what possibly lies beneath its thick ice. A massive lake discovered barely a decade ago, for instance, may be filled with hidden life.
Three separate studies from institutions across the United States offered a fresh first look into the biology and geophysics of subglacial Lake Whillans, which lies 2,600 feet beneath the West Antarctic Ice Sheet.
Back in 2013, an American team drilled into the sliver of water about 7 feet deep, finding microbial life whose density compares to that of the world’s deep oceans with a rich bacteria and archaea population that’s at least 4,000 species strong.
Now, the three separate bodies of research point to a wetland-resembling area beneath the ice, with tiny amounts of seawater emerging from ancient marine matter on the lakebed. Their findings are hoped to help analyze the role of subglacial lakes in water flow from the continent to the ocean — and therefore to sea-level rises.
“It is amazing to think that we did not know that this lake even existed until a decade ago,” said Helen Amanda Fricker of Scripps Oceanography, who discovered Lake Whillans in 2007 from satellite data. “[T]hese new data are helping us understand how lakes function as part of the ice-sheet system.”
Findings On Lake Whillans
Using an array of methods to probe the subglacial system’s dynamics, the three recent papers highlight exciting findings.
The Scripps Oceanography team led by Matthew Siegfried reported in Geophysical Research Letters that GPS data collected in the span of five years indicate that the lake’s periodic drainage can raise velocity at the ice sheet’s base and accelerate ice movement by up to 4 percent in certain bursts, each lasting for several months. These short-term phenomena, the authors suggested, can help scientists better predict upcoming, long-term ice sheet changes.
In the paper published in the journal Geology, Montana State University researchers used data from a 15-inch-long core of lake sediment to describe the chemistry of water in the lake as well as its sediments. Results showed that lake water emerges from melting at the ice sheet base enveloping the lake, with some parts from seawater trapped in sediments lying under the ice sheet when the Antarctic ice retreated during the last interglacial era.
The discovery of an ancient and isolated ocean water reservoir affecting the subglacial lake’s biogeochemistry opposes previous studies from nearby ice streams, which showed no “discernible marine signature” in water obtained from sediments.
The third paper discussed in Earth and Planetary Science Letters investigated sediments from the lake to know their relationship with the ice sheet and subglacial water, demonstrating that although floods occasionally invade the lake, the flow isn’t strong enough to erode expansive drainage channels.
Instead, the habitat underneath is likened to wetlands within coastal plains, where water bodies are likely shallow, broad and with gradual water flow.
Subglacial Lake Research
The 2013 drilling of Lake Whillans through the Whillans Ice Stream Subglacial Access Research Drilling (WISSARD) project retrieved water and sedimentary samples using a customized and clean hot-water drill, which prevents contamination of the pristine setting. It was nothing short of fascinating, as the body of water had been isolated from direct atmospheric contact for thousands of years.
This was unlike the 2012 project of Russian scientists who bore into Lake Vostok, which has been ice-covered for 15 million years. Their claims of finding evidence of life in the lake were met with skepticism due to the water samples unfortunately getting tainted by the fluid used in the drilling.
Science continues to unearth life in isolated water untouched by sunlight, such as two years ago when a team deploying a remotely operated vehicle spotted a species of translucent fish and some tiny crustaceans.
It remains exactly unknown how life was sustained in those areas or where the nutrients come from, but it is speculated by the ecosystems are fed by a certain chemosynthesis where microbes feed on minerals descending from the ice above or seeping through the sediments below.
Proving the existence of Antarctic lakes is seen to boost research on the continent, whose biodiversity is deemed as rich and complex as the deep oceans. A new lake being targeted for exploration, for instance, is far easier to study than Vostok or other remote bodies, as it is located only 100 kilometers (62 miles) from the closest research station.
