Richard Gleeson
Northern News Services

Mount Logan, YT (Nov 26/01) - Scientists are looking into the depths of permanent ice for clues to understanding and confirming climate change.

Like the rings on a tree, layers build up in permanent ice each year. Chemicals locked in each layer provide a frozen record of climate stretching back tens of thousands of years.

Christian Zdanowicz and fellow researcher Gerald Holdsworth, who was part of the first ice-coring expedition to Mount Logan in 1980, take a snow core at a lower camp. - photo courtesy of Natural Resources Canada

Aboriginal Northerners have witnessed the dramatic changes of global warming. They see ice forming later each year, melting of the permafrost and changes in the animals. But that anecdotal evidence does not impress scientists, who regard eyewitness observations as less reliable than data they collect themselves.

Some members of the scientific community still believe climate change is part of a natural weather trend. Ice cores are proving them wrong.

Ice cores taken from the Canadian Arctic and Antarctica are showing that industrial activity, and the greenhouse gases it creates, are causing the planet to warm.

"It's very much a smoking gun, pointing out we are indeed having a major impact on climate," said Geological Survey of Canada scientist Christian Zdanowicz.

Zdanowicz was part of research teams that took ice core samples from Baffin Island, Ellesmere Island, Bylot Island and from Greenland.

He is currently working on a project that aims to fill in historical climate information for the Pacific Northwest. The region has a major influence on North America's climate.

Zdanowicz presented an account of the trip in Yellowknife as part of the Geoscience Forum.

Permanent ice there is very rare in the Pacific Northwest. The farther south you go, the higher you must go to find permanent ice. The highest peak in Canada, Mount Logan, is in the Yukon area of part of the Pacific Northwest.

Near the summit, a plateau 5,340 metres above sea level is covered with permanent ice 225 metres thick. The ice is an archive of climate information for the last 15,000 years.

The research team spent most of the first season hauling up 10 Twin Otter loads of equipment they would need for the project. The equipment was flown to a glacier at base camp, then lifted to the plateau by chopper.

Last May and June they began drilling, pulling out 172 metres of ice core in sections shorter than a metre.

"That puts us roughly in medieval times," said Zdanowicz.

The cores were left on the plateau. When the drilling program wraps up next spring, all the cores will be taken to a lab in Ottawa for analysis.