World of Science | Review ISSW2018: Avalanche accidents

Special Topic Avalanche Accidents (Session 13)

The contributions in this session can be divided into two main categories: On the one hand, individual avalanche periods or avalanche accidents are discussed that were "special" in some way - for example, due to particularly high damage or extreme weather conditions. On the other hand, several research teams or LWDs focus on the long-term development of avalanche accident statistics in their region and corresponding statistical patterns with regard to: "Who? How many? When? Why?"

Individual events, catastrophic avalanches, extreme situations

On the occasion of the 50th anniversary of the founding of the Austrian Board of Trustees for Alpine Safety (KURASI), the two avalanche accidents that were decisive for this foundation were remembered: On January 3, 1965, a group of Dutch youths were caught in an avalanche on the road between Obertauern and the Hotel Scheidegg. 3 people lost their lives. On March 2 of the same year, a coach was pushed off the road by an avalanche not far from the first accident site. 14 passengers died and many more were injured. The second accident also had legal consequences, as the road was open at the time of the accident, and ultimately led to the founding of the KURASI, which has had a cross-organizational, documentary function ever since. In addition, the board of trustees - on the basis of its own now very extensive database - makes recommendations for the prevention of alpine accidents. (The catastrophic avalanches in 1965 near Obertauern and the 50th anniversary of the Austrian Board of Alpine Safety, Höller, O13.3)

One avalanche accident in the recent past that those affected hope will lead to changes in dealing with the risk of avalanches is the accident in Sölden in 2015, in which two young racers from the USA lost their lives. The families of the victims have founded an organization that raises awareness, particularly in the USA and in racing. At the ISSW, the mother of one of the victims called for the danger level scale to be redesigned so that LWS 3 should already represent the maximum, potentially fatal warning level. In addition, communication of the danger and the secured and unsecured areas in the ski resorts must be improved. She also criticized the often trivializing, powder-heavy marketing of many ski resorts (Soelden 2015 avalanche: What can be learned, Berlack, no extended abstract).

The avalanche that destroyed a hotel in Rigopiano (Italy) in January 2017 also had legal repercussions. As part of the investigation and court proceedings, experts were called in to clarify how the avalanche occurred and to investigate the collapse of the hotel from a structural engineering perspective. In a session contribution, they explain the "forensic" avalanche investigation that takes place after a large damaging avalanche.

The corresponding snowpack investigations were not only complex due to the terrain and existing avalanche risk, but also had to be carried out as quickly as possible before conditions changed too much. In addition to the usual snowpack investigations, the avalanche path was measured in detail and forest damage was precisely recorded, as this allows conclusions to be drawn about the avalanche dynamics. Dendrochronological studies can theoretically provide indications of the frequency of large avalanches in certain avalanche paths, but in this case it was concluded that the avalanche was so large that it would have destroyed all the trees that could have "experienced" earlier, similar avalanches. Geomorphological, geophysical and GIS-based investigations indicate that there may have been large avalanches at the accident site in the past, but that these rarely occur (The 18th January 2017 Rigopiano avalanche disaster in Italy - Analysis of the applied forensic field investigation techniques, Chiambretti et al, O13.4).

Less tragic, but spectacular from a weather perspective, was the heavy precipitation in Lower Austria in April 2017. The LWD Lower Austria reviews this event: After the daily situation report had already been discontinued at the end of March, the third week of April was a wake-up call. Over 200 cm of fresh snow fell in 30 hours. On April 20, LWS 5 was issued in the Ybbstal Alps - very, very unusual for Lower Austria - and some roads were closed. Sliding snow avalanches were the main problem. No people were injured and the tone in the (German-language) review by the LWD Lower Austria seems more pleased and fascinated than concerned - when compiling this summary, this was a welcome change between all the not at all pleasing disaster reports (Avalanche Danger Level 5 in Lower Austria in April 2017 - a Case Study, Studeregger et al., P13.6.).

Avalanche databases in other countries

Not every country where avalanche accidents occur has such a comprehensive, centrally collected database on these incidents. On the contrary - in many regions outside the Alps and North America, studies on avalanche accidents have only recently become a research topic at all.

One article, for example, summarizes what is known about avalanches in Bulgaria: compared to the Alps, quite little (Avalanches in Bulgaria - Human and nature perspective, Panayotov, O13.5). Historical records mention avalanches mainly in the context of forest damage. There is still no central database recording avalanche accidents in Bulgaria or mapping of avalanche tracks. Since 2000, the Bulgarian Extreme and Freeskiing Association (BEFSA) has operated an unofficial database, into which information from social media is also fed. The authors emphasize the importance of accident recording for future accident prevention.

In the Romanian Carpathians, avalanche accidents have been documented since 1968/69, in connection with the founding of a Romanian mountain rescue organization. From 1968/69 to 2016/17, 152 avalanche accidents are known in which 154 people lost their lives. Since the 2003/04 season, there has been a nivometeorological department in the Romanian Meteorological Service, which operates an avalanche warning program in cooperation with the Snow Research Center in Grenoble. Since its introduction, as well as the introduction of blasting measures for infrastructure protection, training programs and a generally increasing awareness among the population, the number of accidents has decreased significantly according to this session article (A History of snow avalanche accidents in the romanian carpathians, Voiculescu. No extended abstract)

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The mountain rescue service also records avalanche accidents in Slovakia. In the last 20 years, 67 people have lost their lives in avalanches here. As in other countries, efforts are being made to document alpine accidents as completely as possible, but reconstructing historical events is difficult due to a lack of reliable records. In future, they would like to work together with their Polish colleagues to record avalanche accidents throughout the Tatra Mountains. Avalanche accidents in Slovakia mainly occur where there are particularly large numbers of people in the winter mountains, for example near ski resorts (20 years of avalanche incidents in Slovakia - comprehensive overview, Biskupič et al, P13.4).

No official figures on avalanche accidents are available from Russia, but a team of researchers has tried to gather as much data as possible from various sources (Avalanche accidents in Russia Seliverstov et al., P13.7). The first documented avalanche accident in Russia occurred in 1370 in the city of Nizhny Novgorod, where snow apparently fell down a riverbank and damaged a monastery. In the 1930s and 1940s, there were several catastrophic avalanches in mountain regions, some of which killed over 50 people. Since the early 1990s, the average number of avalanche fatalities has been around 10 per year, mostly affecting locals who are not traveling for winter sports reasons. This has only changed in the last decade: Most of the victims are now tourists. The typical avalanche victim profile also changes over the course of the year: In March, when most skiers are out and about, they are the ones most affected. In February, there are many accidents in which roads are buried. In January, it is mainly local children who die, as they are on vacation at this time. In July - peak season for mountaineers on the higher peaks, where avalanches can also occur in summer - mountain tourists are the most frequent victims.

For completely inexperienced groups who have never thought about avalanches before, it makes the most sense to strengthen cooperation with the hotel industry and rental stores. For example, it could be introduced that snowshoes can only be rented together with safety equipment, or similar measures could be taken to raise awareness.

Another article by LWD Val D'Aran analyzes avalanche accidents in the area in relation to the avalanche problems prevailing at the time of the accident, danger levels, terrain type and results of the AVALUATOR Trip Planning Tool (similar principle to Stop or Go, 3x3). Finding: Most - but not all - accidents occur in complex terrain with LWS 3 and AVALUATOR result "Not recommended" (ATES mapping and typical Problems in Avalanche Accidents or Close-calls in Val d'Aran, Central Pyrenees, Seira et al, O13.6).

Conclusion

"Avalanche accidents" is again one of the broader session topics with a lot of room for interpretation as far as the specific content of the contributions is concerned. Nevertheless, two main topics emerged - "special" individual cases and statistical evaluations of long time series. This shows that the same rule of thumb applies in avalanche research as in many other fields of research: The detailed evaluation of individual events (case studies) is essential for process understanding, as well as method and model development. However, the significance of such events can only be reliably classified in the overall picture if the large-scale patterns and temporal development of this overall picture are understood. This in turn requires a comprehensive and reliable data basis, and creating this is anything but trivial.