After living on the Columbia Icefield for nearly a month this spring, researchers with the Geological Survey of Canada (GSC) are one step closer to answering the proverbial question, "how much does that glacier weigh?"
The team, led by Dr. Mike Demuth, head of the GSC's glaciology department, anticipates their data will allow them, by the end of 2011, to assess changes in the icefield's volume and mass for the first time ever.
This session marked the second year of a five-year project to make a complete analysis of the volume of ice contained in the 223 square kilometre iconic Columbia Icefield in Jasper National Park. In late April, they flew to their site by helicopter with their insulated science/communal tent, personal sleeping tents, food and fuel for five weeks, plus an assortment of scientific equipment. Demuth, Sasha Chicagov, an optical remote sensing specialist with Natural Resources Canada, and John Sekerka, an NRCan environmental chemist - all three based in Ottawa - and Rockies-based glaciology technician Steve Bertollo quickly settled into life at 2,920 metres elevation as overnight temperatures dropped to minus 25 C.
Having been tent-bound for nearly a week during a storm last year, the team hoped a longer stay this year would be productive. By session's end, one day in three allowed radar glacier thickness measurements.
With Parks Canada's assistance, they are conducting surface mass balance measurements of the Athabasca and Saskatchewan glaciers to the top of Mount Snow Dome, measuring glacier thickness and conducting GPS surveys of the icefield. Chicagov is converting NTS (National Topographic System) maps from the 1980s to a format compatible with modern, extremely accurate LiDAR-created ones. Using aerial photos from both eras, he is creating digital elevation models for successive decades. Subtracting one digital model from another will reveal the difference in the height of the glacier by showing where it has become thicker or thinner over past decades.
"With this information, you could ski a line right down from Mount Snow Dome and then have a line showing the same track you took 30 years earlier, and see the difference," Demuth explained.
Since his first of numerous visits to the Columbia Icefield as a climber 30 years ago, Demuth said he's noticed significant changes, as a once "inundated" ice sheet has become more conformed to the bed topography. Comparing elevation measurements recorded in the 1980s to those taken last year reveals a great deal of down-wasting. From a skier's perspective, a historically long, steady ascent toward the Mount Kitchener/North Twin col has morphed into a series of dips and rises. Monitoring such changes on the icefield that ultimately empties into the Pacific, Arctic and Atlantic (via Hudson Bay) oceans is essential as the earth's climate changes.
"Since we are quickly losing some of our long-standing glacier reference points such as the Peyto Glacier, establishing measurements over the Columbia Icefield is a critical strategy for ensuring good observations into the future," Demuth said. "The information we gain will contribute to the assessment of climate change and the fast changing nature of our water and aquatic resources."
Spring is the best time to conduct such research, when winter snowfall reaches its maximum depth before melting begins. After the first week Demuth and Bertollo skied down the Saskatchewan Glacier, measuring its winter mass balance on the way. Bertollo continued taking measurements at other sites in the Rockies and B.C.'s interior and Coast Range, while Demuth skied back up with University of Victoria student Selena Cordeau in one long 10-hour day. Enjoying bluebird skies the first eight hours, they navigated by GPS in a whiteout for the last two.
Cordeau's work examines the region's large-scale weather patterns and seeks corresponding layers in the glacial ice, similar to how avalanche professionals match a surface hoar layer to the extended high-pressure system that created it.
"This information will help us understand how mass balance varies from east to west and north to south, and at different elevations," Demuth said. "Once we have that dialed, we can know that we need to measure over here, maybe over there. Conditions on the icefield are highly variable. Eventually we'll be able to apply her data on a wider scale all over the Columbia."
Staying at the site for a longer period of time this year was beneficial for the sake of science and safety, while an increased quantity of field notes will supplement their raw data back in the lab.
"You certainly gain familiarities with the nooks and crannies of the icefield," Demuth said. "You end up becoming a local expert of the terrain."
While next year's plans include one or more sub-camps to facilitate dragging ground radar equipment northwest toward the Twins, the team left a mass balance stake on Snow Dome's summit with a note asking "citizen scientist" mountaineers to open up the attached dry bag containing a notebook, ruler and pencils.
"Public engagement is important," Demuth said. "We all have something at stake here and some are equipped to help out and tell the story that glaciers have been telling us for a long time. We just have to listen."