The Findel glacier lit up, superimposed with changes in the thickness up to 2009. The colors green to red represent the loss of ice, blue shows increased thickness. (Credit: Image courtesy of University of Zurich)

ScienceDaily (Dec. 11, 2009) — The glaciers in Switzerland have been melting for years. Researchers at the University of Zurich now want to know more precisely how much ice is being lost — and they are using the aid of light.

Changes in the thickness of a glacier are traditionally measured by means of wooden poles and snow-shovels. Those methods are inexpensive and can be carried out to determine the annual or even seasonal result at individual locations. It is, however, difficult to draw conclusions about changes in the thickness of an entire glacier or all the glaciers in the region merely on the basis of those positional measurements. The scientists now want to overcome that disadvantage of direct field measurement by applying laser technology.

Philip Jörg, a Ph.D candidate involved in this project, explains how it works: "A strongly bundled beam of light is shot from an aircraft and the time is measured that the light needs to reach the surface of the ice and bounce back to the aircraft. From this so-called 'run time,' the distance from the plane to the glacier can be precisely determined to within just a few centimetres." The laser data and the exact location and position of the aircraft give rise to a highly precise, three-dimensional picture of the glacier's surface.

49 million cubic metres of ice lost

Researchers at the University of Zurich carried…

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