Melting ice at core of climate study

University of Maine Ph.D. student Bess Koffman monitors a melting ice core at the Orono campus on Tuesday, July 20, 2010. Koffman is melting the cores starting the end that is most recently frozen. Koffman and her coleages hope to learn more about the planet's changes in climate by using this method.
University of Maine Ph.D. student Bess Koffman monitors a melting ice core at the Orono campus on Tuesday, July 20, 2010. Koffman is melting the cores starting the end that is most recently frozen. Koffman and her coleages hope to learn more about the planet's changes in climate by using this method.
Posted July 20, 2010, at 10:21 p.m.

BANGOR, Maine — Bess Koffman is spending her summer watching ice melt.

But Koffman, 29, of Orono doesn’t stand around a lab at the University of Maine’s Climate Change Institute 10 hours a day monitoring any ordinary frozen H2O.

Her ice is ancient. Some sections of the ice cores Koffman is melting this summer are 2,000 years old.

On Tuesday, she spent much of the day looking for evidence of dust in the melting ice from a volcano that erupted in A.D. 186 in New Zealand to see whether it had drifted as far as western Antarctica.

“It would be new and exciting to document that,” the graduate student said Tuesday morning in a demonstration of her research for Bangor-area news outlets. “This volcanic eruption has not been documented in Antarctica before.”

Searching for volcanic dust in ice is at the center of Koffman’s research for her doctorate, which she is on track to complete in 2012. Koffman graduated from high school in Olympia, Wash., and earned her undergraduate degree in geology at Carleton College in Northfield, Minn.

Late Tuesday afternoon, when she examined the computer data collected by a sophisticated machine that measures the amount of dust found in the melted ice and its conductivity, Koffman found no evidence of the particular eruption she’d been looking for.

“The dust and conductivity looks about normal for this time period,” she said, referring to the early years of the second century. “I’ll find out more after I have a detailed chemical analysis, but that will be done in a different lab, and it won’t be available for my use for months.”

Koffman said she was not disappointed in Tuesday’s results because her research includes searching for dust from more than a dozen volcanic eruptions going back 2,000 years. She planned to be back in the lab today to melt another eight ice cores, each of which is a meter, or a little more than 3 feet long, and 3 centimeters square, or about 1½ by 1½ inches.

The ice cores Koffman and other UMaine students use in their research into climate change were extracted three years ago from the West Antarctic Ice Sheet. Koffman was not part of the team that drilled these particular ice cores, but she did process the cores at the National Ice Core Laboratory in Denver.

“Graduate students from around the country travel to Colorado in the summer to saw the cores for their research projects,” she said. “Mine were the right length, but I had to make a 6-inch circle of ice into a 3-centimeter square.”

Koffman said she has been to two research stations in Antarctica — from November 2008 to February 2009 and again the next season. She said Tuesday that earlier this year she worked at the research facility where her ice was drilled.

The University of Maine is one of more than 20 research sites around the country using deep ice cores taken from the West Antarctic Ice Sheet. The research is an attempt to understand how global warming developed before human beings appeared on Earth. By understanding the past, scientists hope to be able to analyze what is causing temperatures to increase in the 21st century, according to previously published articles.

The most significant characteristic of the large body of research is the development of climate records with an absolute, annual-layer-counted chronology, according to information on the website for the overall project. The ice cores taken from Antarctica will provide the first Southern Hemisphere climate and greenhouse gas re-cords of comparable time resolution and duration to the Greenland ice cores in the Northern Hemisphere.

Koffman said Tuesday that her project was a small part of a much bigger picture.

“Just having one more long data set from this research will add to our understanding of the climate system,” she said. “It will be one more piece to the puzzle.”

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