Background on Lake Vostok
The material below is from Chapter 24 of the Complete Idiot’s Guide to the Arctic and Antarctic ©by Jack Williams, 2003. It offers some background on the Feb. 7, 2012 announcement that the Russians had succeeded in drilling into Lake Vostok. The text has not been updated since it was originally written in 2003.
Lakes Are Discovered Under Antarctica’s Ice
As far back as the middle of the 1970s, a few air-borne studies with radar that looks into the ice had led scientists to think that unfrozen water lay under Antarctica’s ice in a few places, especially under the Russian Station on the Polar Plateau. This was interesting, but no one had any pressing reason to look further into the possibility of under-ice lakes.
In 1993, however, more and better satellite data was accumulating and the Scott Polar Research Institute at Cambridge University in England, and the Russian Academy of Sciences began figuring out what was under the ice, especially what was around two and a half miles (4 km) under the Vostok Station.
The respected British scientific journal Nature announced the results in 1996 by putting the news on its cover. It turns out that as many as 70 lakes are under the ice, with “Lake Vostok” by far the largest at about 3,860 square miles (10,000 square km). In fact, the scientists said, it was 10 times larger than any other, known sub-glacial lake. For Americans, the lake is usually described as being about the same size as Lake Ontario. The news of the lakes started some people to wondering whether some kind of life might be in them. Awareness was certainly growing that life is found in all sorts of hard-to-imagine places, but scientists had no particular reason for thinking Lake Vostok or the other lakes harbor life.
Russians Stop Drilling to Avoid Contamination
Before anyone had realized that a huge lake lay under their station, the Russians had started drilling an ice core at Vostok. It was one of several being drilled by various nations, including the United States, in Antarctica, Greenland, and even on glaciers in the middle latitudes and tropics to study past climates. In chapter 26 we look at ice cores and what scientists are learning from them.
With the 1996 discovery of just how large Lake Vostok is, and the speculation that something might be living down there, the Russians stopped drilling at a depth that is estimated to be about 300 feet (100 m) above the lake. The Russians sent samples from the parts of the core from near the bottom, but not from the very bottom, to scientists in other nations, including the United States, to study.
Scientists Find Life in Vostok Core
In December 1999, two research teams, one led by David M. Karl of the University of Hawaii, and John C. Priscu of Montana State University, reported in Science that they had found bacteria in ice from about 11,700 feet (3,600 m) below the surface.
“From a biologist’s perspective, this is the Holy Grail of lake biology,” Priscu said. “Our findings indicate that the microbial world has few limits on our planet. You don’t have to leave the planet to study this completely unexplored system, but the samples sure aren’t easy to get.”
The bacteria found in the Vostok core in 1999 are ones commonly associated with soils, and could have been blown on bits of soil from the Patagonian deserts of South America onto the East Antarctic ice sheet and then buried by snow. If so, the microbes could be more than half a million years old. Another possibility is they originated in the lake and became trapped as lake water refroze to the bottom of the overlying glacier.
Karl noted the one, big outstanding question that remained to be answered in 1999: Whether the ice in which the bacteria were found is sufficiently similar to the water in the lake to allow scientists to conclude that a similar population — or an even larger, more diverse one — might thrive in the suspected liquid water.
News stories about the 1999 findings made much of comments like those of Chris McKay, a NASA planetary scientist and member of Pricsu’s team: “Microbes within the liquid water habitat of Lake Vostok may shed light on the viability of life in similar harsh environments beyond Earth, such as in the frozen ocean subsurface on Jupiter’s moon, Europa. How the bacteria get energy (to survive) is an important question. The lake could be an analog to sub-ice Europa or subsurface Mars where conditions are similar.”
While the cores studied in 1999 were from far down in the hole, scientists were just beginning to study the very deepest ice in early 2003.
How to Study Lake’s Life Is the Question
Once scientists were sure that Lake Vostok holds life everyone involved agreed that the last thing they wanted to do is contaminate the lake. On the other hand, NASA sees Vostok as the perfect place to test devices that could be loaded onto a spacecraft and sent off to explore under the ice of Europa.
Since 1999 scientists have held several international conferences on Lake Vostok, and have agreed that an exploration of the lake must make absolutely sure it isn’t contaminated.
Scientists Learn How Ice, Lake Interact
During the 2000-01 research season, the National Science Foundation picked up the tab for detailed radar mapping and other studies of the ice over and around Lake Vostok. Using the data, Robin E. Bell of Columbia University’s Lamont-Doherty Earth Observatory and her colleagues, discovered how the lake exchanges water with the moving ice above it. This means that while the lake has been sitting there for perhaps millions of years, all of the water in it ends up being replaced every 13,000 years.
First, if you could somehow go down to Lake Vostok, you almost surely would not be able to row around on the lake under a dome of ice, they way you can row around some lakes under a dome of rocks in a cavern. The bottom of the ice sheet is touching the top of Lake Vostok’s water.
Bell explained that the ice sheet is moving from west to east across the lake, “kind of like a conveyor belt” at 6 to 9 feet (2 to 3 m) a year. “That’s when it’s interacting with the lake. As the ice moves across the lake, some of the water on top of the lake freezes to it and is carried along to the east. Water that freezes to the bottom of the ice sheet is replenished. Whether this is from ice on the bottom of the ice sheet that melts directly into the lake, or water that melts elsewhere and flows into the lake is one of the questions to be answered.
These findings mean that researchers can learn a great deal about what’s in the lake by drilling a core down to ice that has moved to the east with lake water, Bell says. “These frozen lake water samples will record the passage of the ice sheet and the processes across the lake.” But, to do this, a new drill site to the east of the current station would be needed.
The Russian Vostok Station is 11,484 feet (500 m) above sea level, which means anyone who goes there faces the danger of altitude sickness. The average high and low temperatures in January, the warmest month, are –27°C (17 and -38°C (-36°F) The United States has built a small, separate camp near the Russian station for U.S. scientists working there.
Anything in Lake at Least 400,000 Years Old
Even though she estimates that all of the water in the lake is replaced every 13,000 years, Bell says, “Lake Vostok is absolutely devoid of interference. The youngest water in it is 400,000 years old. It doesn’t know anything of human beings, fossil fuels, or plastics. It is a window into life forms and climates of primordial eras.”
How can this be? Any water in the lake comes from the bottom of the ice sheet. Scientists calculate that a snowflake, a microbe blown in by the wind, or a cigarette butt dropped by one of the Russian scientists at Vostok needs 400,000 years to work to the bottom of the ice sheet. No, things don’t worm their way through the ice. Instead, the ice sheet is creeping toward the coast where pieces eventually end up floating away as icebergs, and snow continues falling on the top.
New Round of Ice Studies Begins
The Vostok ice in which bacteria were found in 1999 was not from the very bottom of the drill hole. Ice from the bottom 35 feet (12 m) of the core were in a storage trench at Vostok until the 2001-02 season when it was flown to the U.S. McMurdo Station and then put on a ship to France. Pieces of the ice are being parceled out to French, Russian and American scientists.
Those who have seen the ice have commented that it’s much clearer than ice from higher up in the core. This probably means it’s made of water from the lake and could contain life forms from the ice examined in 1999. The bacteria in that ice could have been on their way to the bottom, not from the lake itself.
“The closer you can get down to the lake itself the stronger your argument is that that ice is truly representative of what’s in the lake,” Priscu said. “That’s why we’re striving to get this real clear ice from the bottom.”
Lessons from the Ice
We’ll have to see whether drilling into Lake Vida to discover whether anything is living in the salty water at the bottom, or eventually sampling the water of Lake Vostok help lead to discoveries of life elsewhere in the universe. But, the discoveries of life in Antarctica’s ice “are only a small part of a much larger and more globally important, multifaceted story,” Priscu said. “The earth’s biosphere is larger than we had ever imagined, and the microbial world has few limits on our planet and, possibly, others.”