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DARBY SETS SAIL ON ARCTIC EXPEDITION

Dennis Darby, professor of ocean, earth and atmospheric sciences at Old Dominion University, moved from the punishing heat of Virginia to the punishing cold of the Arctic when he assumed his role Monday, June 13, as a chief scientist of an international research project, sponsored in part by the National Science Foundation.

Results of ocean-bottom mapping, seismic tests, bottom core sampling and ice sampling are expected to give scientists new insights about how the Arctic basin formed and how the climate is changing there.

Darby said Arctic climate changes are particularly interesting and important because they tend to show up later in more temperate zones. But, despite the value of geological and other information that can be gleaned from this far northern region, scientists at present know more about the nature and origins of the surface of the moon than they do about the floor of the Arctic Ocean.

"This ocean is small, but it is critical to the global climate because it acts as one of the primary heat sinks, and if it diminishes in this role, global warming will accelerate far beyond predictions based on models," Darby said. A heat sink is an environment that can absorb heat without an appreciable increase in temperature.

The scientists hope to collect data revealing climate events in the Arctic going back to prehistoric times. The data then will be related to climate events elsewhere. In general, the research is designed to answer questions long resolved for every other ocean basin, but not for the Arctic because of heavy ice conditions.

Darby's objective is to compile high-resolution sediment records from specific drift deposits on the ocean bottom.

The challenge is to locate areas with these drift deposits where deposition rates are higher than the one centimeter per 1,000 years that is normal for the Arctic Ocean. "It's somewhat like looking for the Dead Sea Scrolls and not knowing which cave to search," he said.

For two weeks in June, Darby will be in charge of sediment coring aboard the U.S. Coast Guard's largest icebreaker, the Healy, off the Chukchi Shelf northwest of Alaska.

"We will be breaking 1-2-meter thick ice," he said. "The weather in that part of the Arctic in June could be anywhere from below zero to the low 30s."

For nearly two months beginning Aug. 5, he will be co-chief for the second-and somewhat less bone-chilling-leg of the project, dubbed the Healy-Oden Trans-Arctic Expedition, or HOTRAX.

The Oden is a Swedish icebreaker. This two-vessel crossing of the Arctic Ocean will be only the second ever for surface ships.

HOTRAX will involve about 75 scientists and researchers from at least six countries. Two ODU oceanography graduate students, John Rand and Paula Zimmerman, will be helping with deep-sea coring and bottom mapping during the project. According to Darby, the three of them intend to pose for a picture with an ODU banner when the two icebreakers make a recreation stop at the North Pole in mid-September.

Darby's research in geological oceanography has taken him many times to the Arctic Ocean. He also has worked on the shelf and coastal sediments of the eastern United States. and on gold particle deposits in southwestern Colombia. During the past 15 years he has perfected the "Fe oxide grain fingerprinting" technique, which is the most accurate method of tracing sand grains to their source.

This article was posted on: June 9, 2005

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