UC San Diego researchers are part of an Antarctic mission to explore a mysterious lake, under the Antarctic ice.
Six years ago, Helen Amanda Fricker made a discovery that would forever bond her name to Antarctica and the mysteries that lie beneath its massive ice sheet.
Fricker, a glaciologist at Scripps Institution of Oceanography at UC San Diego and professor at the Cecil H. and Ida M. Green Institute of Geophysics and Planetary Physics, had been poring over data captured by a NASA satellite. The satellite had its laser instrument pointed at the Earth’s surface to precisely locate the “grounding line”—the point where the ice sheet no longer sits on the bedrock below and starts to float on the ocean. Beyond the grounding line, the ice underwent elevation changes resulting from ocean tide activity. Fricker noticed something else interesting in the process of looking at these tidal signals: parts of the grounded ice sheet, where there was no longer any tidal action, were curiously rising and falling at a rate of several meters per year. She had discovered a lake beneath the ice sheet.
The lake, it further turned out, is a component of an intricate Antarctic liquid plumbing network below the ice with interconnected rivers and streams. Scientists have determined that a combination of melting from pressure, friction from sliding ice, and heat from Earth’s interior keeps the sub-ice water from freezing. And as water moves in and out of the lake, it causes the ice sheet to move up and down.
Since its discovery, Fricker has been working as part of a multi-institutional team on a National Science Foundation project with a goal to reach the lake and bring back samples from one of the last frontiers on the planet.
In late January 2013, the team realized its dream.
Drilling through a half-mile of ice, researchers carefully brought back to the surface the first pristine samples from a lake unknown to humanity a few years earlier. And along with the priceless extractions came another flash of news… evidence of life.
DRILLING INTO THE UNKNOWN
Scripps graduate student Matt Siegfried called it “the most suspenseful thing I’ve ever been through.”
For Siegfried, the mission had required 24 hours of air travel from the United States to reach McMurdo Station, the U.S. Antarctic research center located on the southern tip of Ross Island. The journey was followed by several days of intense work preparing and testing field equipment and supplies. “You have to minimize your surprises,” says Siegfried. “When you are camping out on the ice in the middle of nowhere you don’t want any surprises.” There were several more days of frustrating delays because runways had become unseasonably mushy for planes to safely transfer personnel and equipment to the drilling site.
But finally Siegfried found himself huddled in a camp atop Antarctica’s Ross Ice Shelf with 16 of his colleagues around a flat-screen TV and a fresh batch of popcorn. It was a scene that mimicked the intensity of a National Football League playoff game in the waning moments of the fourth quarter. As the camera, fed thousands of feet into a borehole, finally broke through the ice and reached Fricker’s body of water, the mysterious, subglacial Lake Whillans (part of the Whillans Ice Stream system), Siegfried and his colleagues erupted with palpable excitement. Touchdown!
Miles away back home in San Diego, Fricker could sense the exhilaration through frequent updates via text messages from Siegfried.
The celebratory explosion culminated years of preparation and planning. It necessitated a Herculean 983-kilometer (611-mile) trek of machinery and equipment from McMurdo research base to a site above Lake Whillans. Carpenters and other skilled personnel constructed housing and facilities for a 14-day camp that served as the drilling site for the Whillans Ice Stream Subglacial Access Research Drilling (WISSARD) team. GPS data aided the WISSARD team in determining the optimal location for drilling into Lake Whillans. WISSARD researchers then employed a hot water drill to create a 30-centimeter (11.8-inch) hole and penetrate 800 meters (2,624 feet) into the Antarctic ice. Scientists fed instruments down the hole like ice fishermen. Once the scientists penetrated the lake, they sent cameras and instruments to retrieve water and sediment.
One of Siegfried’s main objectives was to work with a WISSARD sub-group that traveled out from the main camp to more than 20 GPS stations spread across a 200- by 100-kilometer (120- by 60-mile) region. The GPS instruments monitor subtle changes in the ice sheet’s elevation. At each station, Siegfried dug into the ice to retrieve the GPS instruments, downloaded the data accumulated since his last visit the year before, and checked the power supplied by car batteries, before entombing the instruments anew in the ice.
Data from the GPS instruments will allow Siegfried and Fricker to more closely study changes on the surface of the ice above Lake Whillans. From this, they can infer the activity of the water beneath. Such information is crucial not only for understanding the water system below the ice but also how the ice sheet is being transformed by the effects of global climate change.
“We don’t know how long the lake has been there,” says glaciologist Fricker. “So the only way you can really tell anything about the history and the context of the impact of the lake on the ice sheet is by going in and collecting samples of water and sediment from the bed of the lake.”
WELCOME TO THE ROCK BOTTOM OF THE FOOD CHAIN
Not long after the WISSARD samples reached the Antarctic surface, the scientists surmised one crucial detail from their water and sediment bounty: tiny inhabitants came back with them. They found life, microscopic organisms, deep down in a dark Antarctic lake. The WISSARD team hopes such primitive life forms and their adaptations can help further science’s understanding of how these “extremophile” organisms manage to survive in such a hardscrabble environment.
Across Antarctica just weeks prior to the WISSARD team’s achievement, another Scripps scientist was investigating the bizarre world of extremophiles.
Geologist Hubert Staudigel’s interest lies in studying how organisms can eke out a living in harsh environments and without a traditional nutrient source. Known as “chemolithotrophs,” organisms that exist without organic compounds or light, these extremophile inhabitants “eat” rocks to survive. Yes, rocks.
Staudigel and his colleagues hunt for such creatures high and low, seeking them by scuba diving in Antarctica’s frigid waters and crawling through pitch-black ice caves atop an active volcano. Not for the timid or the poorly prepared, Staudigel and his colleagues must spend years training as skilled ice climbers to work in ice caves at the 4,267-meter- (14,000-foot-) high Mount Erebus in Northern Antarctica, an environment that challenges the body and mind with extreme cold and wind conditions. His scuba diving training prepares him for research under the ice in seawater temperatures well below the freezing point of fresh water.
“Microbes in deep ice caves are at the ‘rock-bottom’ of the food web, and our work will teach us how life can create new organic matter, just using energy sources derived from volcanic rock and the gases coming out of a volcano,” says Staudigel.
These types of extremes may ultimately help scientists resolve whether organisms exist on alien worlds, such as underneath the icy moons of Saturn and Jupiter, and possibly how life may have started on our own planet billions of years ago.
Some of these organisms, particularly those that dwell in the depths of volcanoes, give scientists a credible glimpse into the infancy of life on the planet.
“Those organisms are likely to be important,” says Staudigel, “because they played a big role at the time when life formed on Earth.”
Mario C. Aguilera, Warren ’89, is assistant director of communications at Scripps Institution of Oceanography, UC San Diego.