Avalanche Terrain Hazard Map covering the Alps
The ATHM
The ATHM shows the extent to which the terrain in the vicinity of a point is likely to trigger an avalanche as a result of winter sports. It is based on specific characteristics of the terrain such as the slope shape, slope size, slope gradients, and vegetation in the vicinity of the point in question. The stability of the snowpack is not taken into account.
Legend
- Transparent: no avalanche terrain
Avalanches triggered by winter sports are unlikely. However, accidents caused by spontaneous avalanches are always a possibility - Green: atypical avalanche terrain
Avalanches triggered by winter sports are not typical in these areas - Blue: typical avalanche terrain
Avalanches can be easily triggered - Red: very typical avalanche terrain
Avalanches are very typical/highly likely in these areas
Comparison with the slope angle map
The map layer we provide that covers slope angles already gives a general view of how exposed the area is. However, the likelihood of avalanches is not affected by slope gradients alone. Compare the following two map sections for examples:
Although point 1 is located on flat terrain (the map on the left), it is very exposed to avalanches (the map on the right). This is not primarily about the run-out area of spontaneous avalanches. A winter person standing at point 1 is close enough to the slope above to be able to trigger it.
Although point 2 sits on steep terrain (the map on the left), it is not actually avalanche terrain (the map on the right). Although it is certainly possible to trigger avalanches from the ridge on both flanks, these avalanches do not usually affect winter sports enthusiasts as long as they stay in the center of the ridge.
FAQs
You should create your route so that it avoids red, blue, and, where possible, green areas.
Avalanche terrain maps are relatively new and as such, certain assumptions are made during their development. Every avalanche terrain map is therefore an interpretation. For an avalanche to be triggered, not only is a certain terrain required, but also an unstable snowpack - a factor not considered in this map. The focus is also on the likelihood of avalanches being triggered by winter sports enthusiasts rather than occurring naturally.
The map is based on official elevation models of the Alps. These elevation models have a high resolution (10 m) and are accurate (~1 m). However, it should be noted that even high-quality elevation models can contain 'artifacts' (errors). This is particularly true near national and regional borders. Artificial snowmaking can also cause the terrain to change considerably. Errors in the elevation model can also negatively impact the quality of the map.
The ATHM is based purely on terrain analysis, i.e. it abstracts from the current snow and avalanche conditions. However, when calculating the relevant slope area, assumptions must be made regarding the triggering distance. These assumptions typically apply to the range between 2 - Moderate and 3 - Substantial. Spontaneous avalanches are possible or probable from hazard level 4- Large. This map does not cover spontaneous avalanches. In addition, greater triggering distances are to be expected at hazard level 4 - Large.
The ATHM is provided by Skitourenguru
Skitourenguru is there to support you in selecting and planning ski tours with low avalanche risk. For this purpose, Skitourenguru assigns a daily avalanche risk to thousands of ski routes in the alpine region.
The ATHM map shows a variety of avalanche risk and avalanche danger maps that have been automatically calculated by software. In individual cases, the maps may be inconsistent or incorrect. Skitourenguru does not guarantee the accuracy of the information. Planning and carrying out your winter sports activities is at your own risk and responsibility.
Liability for accidents or damage that occur in connection with any use of the information on these pages is excluded.