Like many snowbirds, Robert Poreda is heading for sunnier climes next week. The University of Rochester geochemist wouldn't be content on the beach in Florida, though. Instead, for three weeks he'll be camping in a tent in Antarctica, taking water samples as part of his research on climate change and Earth's geological processes.
Poreda will join about a dozen other people in one of the world's most remote places as part of a Long-Term Ecological Research (LTER) project sponsored by the National Science Foundation. The pristine conditions of the Antarctic, and the fragile nature of life there, offer scientists an unparalleled glimpse at the history of Earth's climate and an environment so sensitive that slight changes in today's climate often show up quickly.
Poreda will study the chemistry of a series of lakes thousands of years old, some of the oldest lakes on the planet, in a desert area known as the McMurdo Dry Valleys, part of the largest ice-free area on the continent. It's a place where life is dominated by microbes and mosses, where the highest form of life is a worm. Poreda's efforts will help scientists understand natural climate cycles and human influences on climate.
"This is just about the best place in the world to study the human impact on our ecosystem," says Poreda. "Right now no one is really sure what's happening with the climate, whether the slight upswing in temperature over the last few thousand years is just a normal fluctuation or whether temperatures will keep rising. These are the kinds of questions we're trying to answer. A long-term increase could raise sea levels globally, possibly flooding out millions of people and causing years of extremely cold winters at high latitudes such as Europe."
Poreda's search for answers will begin with a series of flights taking him to Christ's Church, New Zealand. Then the geochemist, an associate professor in the Department of Earth and Environmental Sciences, will take an eight-hour flight to McMurdo Station, a village in Antarctica with about 1,000 residents. After a two-day course on wilderness survival, he'll head by chopper for a remote camp near Lake Hoare.
At Lake Hoare, Poreda will be one of about a dozen researchers sharing laboratory facilities at a base camp and sleeping in tents scattered around the camp on a rocky landscape in the shadow of 5,000-foot mountains. Part of each day will be devoted to forays into the wilderness, where Poreda will hunch over ice-covered lakes and drill through deep ice to obtain water samples. Since Antarctica is basking in the middle of summer, Poreda will have the benefit of 24 hours of sunlight every day. Temperatures won't be much different from Rochester's, with the thermometer likely hovering between 0 and 10 degrees Fahrenheit for most of his stay.
Poreda has already shipped much of his equipment to the area via an ice-breaker, and the hundreds of water samples he collects will return to Rochester the same way. In his University laboratory, Poreda will use a rare-gas spectrometer to analyze the samples, trying to learn what lives within the lakes, how fast water flows into and out of them, and how biologically active they are.
Earth's climate is not the only one Poreda will be learning about. Of all the places on Earth, the McMurdo Dry Valleys region of Antarctica is the place most similar to that of Mars. Poreda will scour the hillsides for clues about the geological evolution of that area of the Earth, and how similar conditions might have helped shape Mars. He'll also be on the lookout for Martian meteorites: In addition to the dry climate, glaciers in the area push around meteorites in such a way that the meteorites tend to accumulate in certain spots. "It's a meteorite prospector's dream," he says.
The trip is not Poreda's first to the far reaches of the Earth. Back when he was a graduate student in the late 1970s and early 1980s, he spent time along the border between Rwanda and Zaire, climbing up 10,000-foot peaks for samples. He has also cut his way through the jungles of the Philippines and Papua New Guinea in search of just the right rock samples. And he has spent time on the remote Aleutian islands off Alaska, collecting volcanic rocks to learn about the processes that rule the Earth's interior.
"You're cold, you're hungry, and you have to decide if you want to risk crossing a snow field for a few more samples. It's 3,000 feet down. How bad do you want that sample?" asks Poreda. "This is not without risk. It's what the process of discovery is all about. It drives the human spirit."