Study: Already shrunk by half, Swiss glaciers are melting faster
GENEVA (AP) — A new study has found that Switzerland’s 1,400 glaciers have lost half their total volume since the early 1930s, and researchers say ice retreat is accelerating at a time of growing concerns about climate change.
ETH Zurich, a respected Swiss Federal Polytechnic, and the Swiss Federal Institute for Forest, Snow and Landscape Research announced on Monday the results of a first-ever reconstruction of ice loss in Switzerland in the 20th century, based in part on an analysis of changes to the topography of the Glacier since 1931.
The researchers found that the ice volume had shrunk by half over the next 85 years—by 2016. Since then, glaciers have lost another 12% in just six years.
“Glacier retreat is accelerating. It is important to closely monitor this phenomenon and to quantify its historical dimensions, as it allows us to infer glacial responses to changing climate change,” said Daniel Farinotti, a co-author of the study, which is published in the scientific journal The Cryosphere has been published.
In terms of surface area, the Swiss glaciers make up around half of the entire European Alps.
The teams drew on a combination of long-term observations of glaciers; measurements in the field; and aerial photographs and photographs of mountain peaks—including some 22,000 taken of peaks between the two world wars. By using several sources, the researchers were able to close gaps: only a few Swiss glaciers have been regularly examined over the years.
The research involved using decades-old techniques to allow comparisons of the shape and position of terrain images, and using cameras and instruments to measure the angles of land areas. The teams compared the surface topography of glaciers at different points in time, enabling calculations on the evolution of ice volumes.
Not all glaciers lost ice at the same rate, the researchers said. The elevation, the amount of debris on the glaciers, and the flatness of a glacier’s “snout”—its lowest part that is most prone to melting—all affect the rate of retreat.
The researchers also found that two periods — the 1920s and 1980s — did experience sporadic growth in glacier mass, but this was overshadowed by the broader trend of retreat.
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