Lack of snow: Bad for skiing, benefits for permafrost

The Swiss Alps has never seen such little snow at this time of year before. The historic lack of snow has drastic consequences, but not for the permafrost.

The lack of snow in the Alps has far-reaching effects, for example on tourism or the water supply. However, the very thin snow cover or, in some places, no cover, has a positive influence on the permafrost.

The frozen ground can actually cool down more than it would be able to in a snowy winter. This is because snow is an excellent insulator and shields the permafrost from the icy air above.

At very high altitudes above 2500 m, where the alpine permafrost mainly occurs, the temperatures in winter are often deep in the minus double-digits.

With a metre-thick layer of snow, it is very difficult for this cold air to penetrate the subsoil. On the other hand, if the ground is exposed, the surface and deeper soil can actually cool down more.

However, snow is not always bad for the permafrost. In summer, it is exactly the opposite, as the remaining snow protects the permafrost from the summer heat.

Ideally, a winter with little snow is followed by large amounts of fresh snow in spring, in order to build up the "protective layer" at the right time.

In recent years, the very hot summers have affected the permafrost in the Alps. The upper layers heated up sharply, causing slopes and rock faces to lose stability. In summer 2022, increased rockfalls were reported.

At the Matterhorn for example, it became too dangerous for mountain guides to offer tours to the world-famous summit.