1,200 lakes form in Swiss glacial regions since Little Ice Age

Only a few years ago the Silvretta glacier in the canton of Grisons covered the spot where due to glacial recession a lake has formed. Keystone / Arno Balzarini

A comprehensive inventory of Swiss glacial lakes found 1,200 have appeared since the end of the Little Ice Age (around 1850).

This content was published on July 19, 2021 - 10:45

Climate change is causing the Alpine glaciers to melt, according to the findings published last week by the aquatic research institute. When massive ice fields retreat, they often leave behind depressions and natural dams in the exposed landscape. Meltwater fills the basis forming new glacial lakes.

About 1,000 of the 1,200 new lakes that took shape since the mid-19th century still exist today.

“On the one hand, we were surprised by the sheer numbers and on the other by the marked acceleration in formation,” says Daniel Odermatt, head of the remote sensing group at the institute. “At the beginning of the project, we expected a few hundred glacial lakes. Now there are over a thousand, and 180 have been added in the last decade alone.”

Researchers from the University of Zurich and the Federal Office for the Environment also participated in the survey of glacial lakes formed over the past 170 years.

They drew on high-quality aerial photo data and substantial archive material. Naturalists noticed and mapped the changes of some large glaciers in the Swiss Alps between 1840 and 1870.

The researchers also referred to an American survey carried out in 1946, which marked the beginning of high-quality aerial photography.

The Swiss inventory looks at changes to the glacial landscape using data from seven points in time between 1850 and 2016. The results can be viewed hereExternal link.

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