Mount Piz Segnas, left, and the Tschingel Horn mountains, right, with Martin's Hole near Elm in the canton of Glarus, are pictured in Switzerland. File picture: Gaetan Bally/Keystone via AP

Geneva - A fifth of Switzerland's glacier volume has melted away over the past 10 years, the Swiss Academy of Sciences said Tuesday after the past record summer delivered a further blow to the country's iconic Alpine ice.

The melt water over the past decade could cover all of Switzerland's 41,285 square kilometres with 25 centimetres of water, according to the Academy-funded Swiss Glacier Monitoring Network.

Summers with unusually high temperatures have become more frequent in the country, and the past April-September season was the hottest since records began in the 1860s.

The permanent ice cover on the Alpine peaks lost 2.5 per cent of its volume over the past 12 months.

Receding glaciers increase the risk of large landslides and floods caused by overflowing glacier lakes.

Although Switzerland saw unusually large amounts of snow last winter, most of it melted away during the dry spring and hot summer.

"Many glaciers completely lost their snow cover in the past months," said Andreas Bauder, one of the network's scientists.

This is problematic because the white winter snow reflects the sun and protects the darker glacier ice underneath, he told dpa.

In addition, fresh snow is necessary to sustain glaciers over longer periods, because it can turn into ice over the years, Bauder added.