B.C. glaciers 38 per cent thicker than expected, surprising study finds
Extensive radar surveys on five glaciers in the Columbia River Basin has found the ice is 38 per cent thicker than originally believed, according to a new study from the University of Northern British Columbia.
Lead author Ben Pelto and his colleagues skied cross country on the glaciers over 182 kilometres, pulling a sled-mounted ice-penetrating radar system to collect thousands of measurements.
They found the total volume of ice in the basin is roughly 122 cubic kilometres, or about 23 per cent more than computer modelling had estimated.
“I was surprised that the models were off by that much,” said Pelto, who completed the work with support from the University of Victoria’s Pacific Institute for Climate Solutions and from B.C. Hydro. “There are about 17,000 glaciers in B.C. and until now we only had ice measurements from a handful of them.”
After three years of collecting data in the field, those knowledge gaps are starting to close and Pelto’s cardiovascular fitness is likely well above average.
Previous estimates, based on computer modelling, used a variety of surface measurements to estimate the thickness and volume of glacier ice over very large areas, such as all of Western Canada or even the entire planet, so some variability is to be expected.
“Those models work pretty well in the absence of data, but you don’t really know how thick the ice is until you measure it,” he said.
The study — “Bias-corrected estimates of glacier thickness in the Columbia River Basin, Canada,” published in the Journal of Glaciology — considers more than 34,000 data points in the Columbia Basin and two glaciers in the Rocky Mountains.
While the findings are “a bit of good news story,” they don’t change the prognosis for glaciers, which is quite dire.
“I’m glad they are thicker than we thought, but it won’t have much impact on the survival of these glaciers,” he said.
“Some of them might last a few years or even a decade longer, but it won’t save them from climate change,” he said. “Glaciers will disappear from the basin in about 65 to 80 years.”
Putting a slightly bigger ice cube in your drink doesn’t change the outcome for the ice cube, explained co-author Brian Menounos, Pelto’s PhD supervisor.
“The fate of the glaciers is going to be determined by greenhouse-gas emissions, especially over the last 30 years and the next 80,” he said.
An earlier study led by Menounos found that B.C. glaciers are melting at four times the rate in the past 10 years compared to the decade before.
The new data collected by Pelto will be crucial to testing and validating better computer models that inform the decisions of water and land managers and government climate policy, Menounos added.