INNOVATION November-December 2015

fea t ure s

CRYSTAL CLARITY Radar Devices Reveal Secrets Hidden in Ice

Krista Zala

The postwar commercial availability of radar technology revolutionized flying and opened up the skies to aerial exploration. In the 1950s, a series of unexpected crashes in Greenland—where pilots coming in to land hundreds of metres above rock were unaware of the glacier metres below—revealed ice’s transparency to radar. Since then, engineers have developed technologies to gauge a glacier’s depth and sketch profiles of its many and varied layers. Ice-penetrating radar is typically a ground-penetrating radar system tweaked to detect ice features. For glacier surveys, it’s achieved by dropping the frequency to 20 MHz or less and adding a correspondingly long antenna. A surveyor might place an ice-penetrating radar device on a sled hooked to a skier or vehicle for quick roving surveys in safe terrain, strap it onto two modified skis when crevasses and other hazards necessitate a walking pace, or

Researchers collect under-ice lake data amidst freezing winds on Williston Lake, BC, and encounter a glacier-melt stream on Kaskawulsh Glacier, in the Yukon (inset). Photos: Advisian/Worley Parsons, and Laurent Mingo, P.Eng. (inset)

fasten it to one spot for a time-series recording. What follows are a few examples of how such technologies developed by APEGBC members are used across Canada to reveal information within and beneath ice. Glaciers For years, Simon Fraser University researcher Gwenn Flowers has studied hydrological activity of glaciers in the Yukon’s Kluane National Park. “Glacier behaviour has implications for sea level, local water resources, hydro power, agriculture, and habitat,” Flowers explains. By studying “how water flows under the ice and how

27

NOV E M B E R /D E C E M B E R 2 015

i n n o v a t i o n

Made with FlippingBook - professional solution for displaying marketing and sales documents online