Glaciers: why training or a guide is needed

Glaciers form where, over many years, more snow falls than melts in summer. The snow is pressed into ice under its own weight, and this ice begins to flow slowly downhill under gravity. In the upper area snow often stays lying and covers crevasses; in the lower area the snow melts away in summer and the bare ice with its crevasses becomes visible. That is why the snow-covered upper part is so deceptive.

Crevasses form where the ice stretches: over steps in the terrain, at bends and along the edges. Snow bridges covering crevasses are usually firmer in the cold of night and early morning and weaken as the day warms. Where the glacier flows over a steep step, an icefall forms, with towers of ice that can collapse unpredictably.

The surroundings are dangerous too. Moraines – ridges of debris left behind by the glacier – are often loose and slippery. Meltwater streams can be fast and ice-cold and swell strongly during the day. At the glacier snout, where the stream emerges from under the ice, and in ice caves, large pieces of ice can fall without warning.

A rope team only protects you if everyone in it knows what they are doing. If someone falls into a crevasse, the others must hold the fall, anchor themselves and haul the person out with a pulley system. That is physically and technically demanding and only works if it has been practised beforehand under supervision. A rope in the pack without this skill does not help – in the worst case it pulls others in too.

Glacier courses run by alpine clubs and mountain schools teach walking on crampons, roping up correctly, holding a fall and crevasse rescue. These techniques are deliberately not described here, because they cannot be learned safely from a text. Anyone without training hires a certified mountain guide.

Local knowledge matters too. Hut keepers, mountain guides and regional bodies know current conditions, such as where crevasse zones have shifted or whether an approach is still passable. Glaciers change from year to year, and older descriptions in books or online may be out of date.

Even a harmless-looking, snow-covered glacier surface can hide crevasses. Other people's tracks are no guarantee: a snow bridge that held in the morning can give way in the afternoon. Anyone who goes onto a glacier without training and a rope team or a guide exposes themselves to a danger they can neither see nor control.

Glacier snouts, ice caves and overhanging ice walls are off-limits – even for a quick photo. Ice can break off there at any time, and the weight of even small chunks is enormous. Also keep away from glacial streams and moraine slopes, especially on warm afternoons when meltwater and rockfall increase.

In a crevasse fall or accident, call the local emergency number at once (112 in the EU). If you have no signal, use the alpine distress signal: six signals a minute, then a minute's pause. Mountain rescue teams and helicopters are trained and equipped for such operations.

If you simply want to see a glacier up close, you do not need an alpine tour. Many mountain regions have marked, secured paths to viewpoints at the glacier's edge, as well as guided glacier walks in which a mountain guide protects the group. Barriers and notices there are to be taken seriously.

With glacier retreat, glaciers today are changing faster than before. Approaches become steeper and looser, moraines unstable, and new lakes appear. That makes on-site information even more important than it used to be.

Anyone who wants to do glacier tours later begins with sure-footed walking in the mountains, gains experience on crampons and then takes a glacier course. After that come tours with experienced people. This path takes time, but it is the only one that truly holds on glaciers.