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Hoping to find clues of global climate change in the world’s seventh-largest river system, a team of USC students and professors will spend seven weeks this summer on the Lena River in northern Russia.
The three-year project, part of the National Science Foundation’s Arctic Freshwater Initiative, is aimed at studying the history of the Lena, which supplies 30 percent of the freshwater discharged into the Arctic Ocean. That freshwater flow into the Arctic’s frigid waters is believed to alter deep oceanic currents in the North Atlantic, and, ultimately, affect global climate.
“We’ll travel 2,500 miles on a Russian river freighter from the Lena’s headwaters to the Laptev Sea, taking samples along the way,” said Doug Williams, a geology professor and associate dean of the Honors College. “By extracting cores from the bottom of the Laptev Sea, we can look at the past 500 to 1,000 years of climate history.”
Six undergraduate and two graduate students will accompany Williams and fellow scientist Eugene Karabanov on the trip. A team of 10 Russian scientists will join the USC contingent.
Climate scientists consider North Atlantic ocean currents among the key regulators of global climate. The Gulf Stream carries warm Atlantic surface water north until it cools, descends, and drives deep-water currents back toward the equator. Scientists think this gigantic conveyor belt of water flow—called the thermohaline conveyor—could be disrupted, perhaps even stopped, if freshwater flow into the Arctic Ocean continues to increase, changing the salinity of seawater in the North Atlantic.
“Precipitation levels have increased across northern Russia, which has fed the flow in the Lena River,” Williams said. “On top of that, the permafrost in parts of northern Russia has begun to melt, which has created even more freshwater runoff into the Arctic.”
This summer, the USC and Russian team will travel down the Lena River during its peak discharge season, analyzing water samples along the way. They will spend another three weeks on the Lena River delta, taking core samples from the bottom to determine the past history of freshwater flow. During the next two summers, the team will venture further out into the Laptev Sea after the ice has receded.
To prepare for this year’s trip, Williams and the USC students camped out during spring break at North Island near USC’s Baruch Institute field lab, taking water samples and sediment cores in Winyah Bay.
“It was a team-building experience,” Williams said. “Everybody learned a lot about what has to get done, no matter what the weather conditions.”
.04/03
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USC geologist Eugene Karabanov pulls a coring apparatus ashore at Winyah Bay during a training session to prepare for the Lena River expedition in May.
