snow sports are part of the active tourism of the winter season, when we can Make the most of the white blanket that surrounds the ski slopes. But this white layer is not homogeneous but rather presents a series of layers that correspond to the different snowfalls that have fallen.
To practice winter adventure sports, in principle, you can differentiate between weak, poorly cohesive layers and strong, very cohesive layers. It is essential to evaluate the different strata to ensure the stability of the terrain and plan our itinerary based on the type of snow we face (see snow safety).
Very cohesive snow
As soon as the snow crystals are deposited, they begin to change shape and the future resistance of the snow cover depends on these changes. When the temperature of the snow cover is uniform in all its layers and not very low, the snow forms rounded crystals closely linked to each other. This creates a very cohesive, very compact layer. These crystals are the most stable and persist for long periods of time.
If an outer layer of this type is deposited on a weaker one, the danger of an avalanche is great, since the compact layer can detachand slide in blocks, so causes a plate avalanche.
Powder snow
Also called "sugar snow". If there are temperature differences in the snow cover, the snow forms crystals modeled in facets, called faceted. These crystals do not create strong bonds, so the layer that is created is weak, not very cohesive. This type of snow has a light consistency, it is not compact but loose and allows you to slide through it quickly. When skiing on it, "dust clouds" appear, which give it its name.
Hard powder snow
It consists of a compact base on which a thin layer of powder snow falls. It is common in ski resorts, where the compact base is created with snow grooming machines. Off the slopes, it occurs when a light snowfall falls on a very stable layer.
frost depth
When sugar snow is buried under other layers, it is called deep frost. Avalanches often occur when snow falls on a stratum of this type, formed after a period of cold, clear weather.
Other types of snow
- Virgin snow. It is that which neither skiers nor snow plows have passed through.
- Snow tread. This is snow that, for example, the snowplow has passed through. In a ski resort, the passage of the machine leaves compact snow on which it is easier to ski.
- Crust snow. It is created when there is a large temperature difference between day and night. As the temperature drops at night, the surface snow is the first to cool, the water freezes and creates a very firm layer of snow, like a crust. It can also be produced by the action of the wind on a layer of powder snow. It is one of the most difficult types of snow to ski.
- Snow soup. It is not warm, in fact, it is also called wet snow or potato snow (but without potatoes). It is created by the opposite process to the one we just described. As the temperature rises during the day, the snow thaws and a layer of poorly cohesive snow remains, with a high water content. It is also difficult to ski on.
- Surface frost. This is a layer of snow or ice, usually very fragile, that is caused by condensation of water vapor on the surface of the snow. It usually forms on cold, clear nights and is the solid equivalent of dew. Although surface frost usually forms a thin layer, which is easily destroyed by wind or rain, it can also gain consistency by joining other layers. Its instability depends on its thickness, which can vary from one millimeter to several centimeters.
- Grainy snow. This is the name given to snow whose flakes have been transformed into grains, which are welded together.
- Sastrugi. This is the name given to the layer of snow with ridges or undulations that originates with the wind.
- Snow. Very hard type of snow found on glaciers and perpetual snowfields.
- Artificial snow. It is produced with cannons that expel sprayed water, which transforms into snow if the temperature is appropriate. Once it falls it will be modified like the rest of the snow due to the action of the wind, temperature changes, etc.
