A Northwestern research team was dropped by helicopter in the desolate wilderness of Greenland with four weeks of provisions and the goal of collecting ancient specimens preserved in Arctic lake beds. This was not the plot of a reality TV show. It was how a group of rugged scientists, led by Northwestern geologist Yarrow Axford, began an Arctic field research expedition to investigate climate change near the rapidly melting Greenland ice sheet during the summer of 2014.
The samples they collected are of great interest to the scientific community concerned about global climate change and Greenland’s shrinking ice sheet — the second largest in the world and the only contemporary ice sheet outside of the Antarctic. Covering three-quarters of Greenland, the ice sheet is now losing hundreds of billions of tons of ice a year.
“Lakes are libraries of information about the past,” said Axford, an assistant professor of earth and planetary science in the Weinberg College of Arts and Sciences who has traveled to the Arctic for research 16 times. “They are amazing at preserving things.”
Axford’s team is particularly interested in samples from the past 11,700 years, known as the Holocene Epoch.
Now under analysis in Axford’s lab at Northwestern, the samples the team collected range in age from modern day to an estimated 130,000 years old and show climate changes that occurred over multiple glacial and interglacial cycles. The mud and sediments contain layers of organic material such as insects, pollen and mineral grains that have accumulated year after year.
“These lake sediment cores provide geological records that reveal a picture of Greenland’s changing environment over thousands of years,” Axford said. “If we understand its past, we can better predict how the ice sheet will respond to climate change in the future.”
The trip is part of a larger collaborative climate change research project, supported by the National Science Foundation’s Office of Polar Programs, with scientists from Northwestern, Dartmouth College and the University of Maine. Axford also has support from the Institute for Sustainability and Energy (ISEN) at Northwestern for her research in Greenland. The team will publish what they find in the samples over the next few years and combine what they’ve discovered with their research partners.
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Edited by Andrea Nazarian, a student in Northwestern's Master of Science in Communication program.