Antarctic Research
IT'S COOL!
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A native Emperor penguin inspects
All photos courtesy NSF and the
An icebreaker opens a path
Using hot water to drill, engineers and
Diving below the ice, biologists follow penguins |
It comes as no surprise that Antarctica is a haven for glaciologists and snow experts. The frozen
continent also draws astronomers and astro-physicists who like the clear skies and nights that last
six months. Geologists and climatologists are intrigued by the well-preserved remnants of the
past. And oceanographers gather information about the water that flows beneath the floating ice
shelves and sea-ice.
What does come as a surprise to some is the amount of biological research that takes place at the NSF-funded research stations. Human researchers adapt to temperatures of 32 o F to -100 o F by importing warm coats, portable housing and food. Bacteria, plants and animals, however, adapt biologically. What is also surprising is the number of researchers who leave their warm homes to go there, not just willingly, but eagerly. They say the science explored on the Ice, as the researchers refer to it, is like no other. While in Antarctica, scientists live for their research -- and the research is far from routine. Antarctica is a place where scientists dive below the ice sheet to follow penguins and seals. They set up tents on ice floes that can break apart with little notice. They deal with problems of recording data when their pens freeze at -4 o F. They adjust telescopes when the O-rings shatter in the cold. And they gain the muscles needed to drill tens of feet into the ice for samples. Antarctica is not a place for the faint of heart. It is impossible to mention all of the projects going on in the three NSF-funded year-round research centers. What follows is just a glimpse of a few of the hundreds of studies taking place at the coldest place on Earth.
Ice Cores Hold Earth's ClimateAs ice forms, gasses and other materials are trapped in the layers that build up over time. This makes Antarctica practically a time machine. With more than 500,000 years of snow and ice accumulation, paleoclimatologists find the ice sheet an ideal place to set up their tubular drills, extract cores and read the history.What they're discovering is that Earth's climate is not stable, and never has been. Ice ages are punctuated by interglacial periods of relative warmth -- such as the one we're currently in. The interglacial periods have been marked by sudden shifts in temperature, wind patterns and sea levels. "Some of these rapid changes occur in two decades," says Paul Mayewski, a glaciologist from the University of New Hampshire and a 30-year veteran of Antarctic research. "Some [of the changes in patterns] actually start in less than two years." While he finds these dramatic shifts surprising, he also notes that Antarctic cores are in sync with the climate data found in the ice cores from Greenland. Mayewski and his colleagues learn about these changes by examining the chemical indicators, such as seasalt, within the cores. High seasalt levels signal increased storminess and stronger winds. In addition, measurements of oxygen isotopes reveal cooling during periods of increased seasalt. Other tests probe for indicators of wind patterns, volcanic activity and sea level. Researchers studying the world's deepest core have differentiated more than four ice ages, or about 400,000 years of history. Working in the center of Antarctica's ice sheet, near the Russian base of Vostok, the team of scientists from the United States, Russia and France expect ultimately to drill through a total of two miles of ice, or at least 500,000 years of Earth's past. But they may have to stop short. Radar images show that their site is located above a body of fresh water about the size of Lake Ontario. They plan to drill to 150 feet above the lake, and then stop so as not to contaminate it. The site where Mayewski's team works is closer to the sea. The evidence of rapid climate changes is stored in the cores there, he says, just as it is in the Greenland Ice Sheet core. However, in neither case have the scientists found clearly defined causes of the rapid changes. "We need to understand how these changes work in order to make a better assessment of natural climatic change," he says, "and a better assessment of the human impact on the future climate."
Diving Below the Ice: The Life of EmperorsOn the other side of the glass in Gerry Kooyman's observation chamber, Emperor penguins whiz through the water, their torpedo-like shapes giving them a grace of movement denied to them on land.Kooyman, from the Scripps Institution of Oceanography, and his colleagues have learned that penguins are virtual diving machines, descending to depths of up to 2,700 feet, spending as much as 20 minutes underwater, resurfacing and diving again.
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The birds are the most visible of the continent's native fauna. Their stamina for cold and ability to dive have brought Kooyman back for 30 seasons of study. He's become such a fixture that his colleagues named a mountain after him.When Kooyman began his work, there was no equipment built specifically for the study of penguins. Today, the research team -- which includes Kooyman's sons -- uses many pieces of equipment adapted and designed for penguin studies. The divers, for example, work in an aptly named anti-leopard seal cage to avoid becoming protein for the aggressive seals.
While Kooyman wants to know about the tuxedo-clad birds' lifestyle, he is also interested in their physiology. How do these birds metabolize oxygen as they quickly descend to enormous depths, and then equally quickly ascend? This behavior would kill humans. How do the penguins withstand cold of 100 o below zero F? Understanding these capabilities may ultimately translate to human medical advances.
Researchers are keeping a close eye on the Emperors because they may be one of the indicator species for global change. Penguins are dependent on Antarctica's ice for their home and, to a certain extent, on a shrimp-like zooplankton, called krill, for their food. Changes in the ice and the plankton populations will affect the birds quickly. Gerald Kooyman will be one of the people watching.
At Home In The Ice
In Antarctica, the sea-ice temperature dips down to -4 o F, a cold place to start a garden. Yet, inside the collection of crystallized water and salty brine, algae live, photosynthesize and grow.At first, no one believed the algae actually lived in the surface layer of sea-ice, says oceanographer Diane Stoecker of Horn Point Environmental Laboratory-part of the University of Maryland system. Most people thought the algae, known as dinoflagellates, were accidentally trapped when the sea-ice froze. But Stoecker and her colleagues have proven that algae make themselves at home in one of the coldest and saltiest places on Earth. Furthermore, in doing so, the algae effectively shade the plants and animals that live below, and their brown color may affect the melting of the sea-ice.
Far from enduring a hardship, the sea-ice-dwelling algae actually have a good deal, Stoecker says. "The algae get the sun long before the other microbes in the water; they have almost no competition and they're protected."
In early spring, algae located within four inches of the surface start to grow through photosynthesis. Then, before the sea-ice breaks up for the summer, the algae go dormant, forming protective cysts. With the ice breakup, some of the algae become plankton food. Other parts float away, safe until the next growing season.
In addition, Stoecker's studies are showing that the algae have a role in global climate. When eaten, the algae release a gas that becomes dimethyl sulfide in the atmosphere. This gas is important as a nucleus for formation of water droplets that form clouds.
Other Projects on the Ice
- Carbon and Climate in the Southern Ocean.
Led by Robert Anderson of Columbia University and Walker Smith of the University of Tennessee, researchers are examining the role of the Southern Ocean in the global carbon cycle and ultimately expect to use the information to predict the ocean's response to climate change. As the southern component of the decade-long Joint Global Ocean Flux Study (JGOFS), the effort includes 13 cruises, some of which will focus on phytoplankton blooms in the Ross Sea and the role of these phytoplankton in the global carbon cycle.
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Antarctica's dry, unpolluted atmosphere
All photos courtesy NSF and the |
The Antarctic Muon and Neutrino Detector Array (AMANDA) makes use of the continent's ice sheet to detect subatomic particles that may hold clues to activities going on inside and outside of our own galaxy. Physicists explain that subatomic particles may indicate distant galactic disturbances, such as supernovas. In the first nine months of observation, AMANDA spotted many particles that seem to be evidence of neutrinos, one type of subatomic particle. Last season, researchers added six new detectors to the four already working.
Last summer the news startled everyone: A meteorite from Mars may contain fossils of early life. This news drew the spotlight to the Antarctic Search for Meteorites, and to Allan Hills, where the famous meteorite, ALH84001, was found. During this last November-January research season (Antarctica's summer), researchers continued the search for Martian rocks, concentrating on Allan Hills and other Antarctic locations.
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