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This article examines the characteristics of inbounds avalanche fatalities at ski areas in the United States. The study analyzes data from accidents that occurred within ski area boundaries during operating hours and resulted in a fatality. The researchers categorized the avalanches based on circumstances, such as closed terrain, outliers, and open terrain with or without mitigation. The findings highlight the importance of ski area closures, the challenges of mitigating wet slab avalanches, and the risks associated with unmitigated starting zones outside ski area boundaries. The study emphasizes that while inbounds avalanche fatalities are tragic and rare, the risk cannot be completely eliminated, and efforts should be made to further reduce these incidents. The document also discusses key characteristics of recent inbounds avalanche events, including aspects such as slope angles, runout zones, time of year, weak layers, crusts, slope opening, skier traffic, and multiple skiers involved. It explores inbounds avalanche litigation and the understanding of post-mitigation release avalanches. The document concludes with considerations and conclusions for avalanche professionals to mitigate avalanche risk, emphasizing that while ski area avalanche mitigation programs have reduced the risk, inbounds avalanches are still an inherent risk of skiing. [Extracted from the article]

The ICAR 2024 Avalanche Commission Report discusses various topics related to avalanche safety. One focus is on beacon interference, which can occur passively when metal objects temporarily affect the antennas in a beacon, and actively when electronic devices near the beacon in search mode cause interference. Different manufacturers presented their approaches to dealing with interference, such as alerting the user or reducing the search strip size. The report also covers other subjects, including a modified risk assessment model, searching in parallel, and updates on avalanche incidents from different countries. Additionally, there is information on electronic airbag interference and a demonstration of a helicopter hoist during the conference. [Extracted from the article]

The article discusses the role of luck in avoiding avalanches. It explains that luck is a factor in avalanche avoidance, but skill and experience can minimize the reliance on luck. The article emphasizes the importance of improving skill and reducing luck through training, knowledge, and experience. It also discusses the human tendency to create narratives and simplify complex experiences, as well as the need to focus on the decision-making process rather than just the outcome. The article provides tips for improving skill and reducing luck in avalanche situations. [Extracted from the article]

The article explores the concept of expertise in the context of snow and avalanche safety. The author challenges the idea that experience alone equates to expertise, emphasizing the importance of intentional practice, purpose, and continuous learning. They argue that expertise requires focus, repetition, review, and refinement. The article also discusses the difference between expertise and mastery, highlighting the need for mindfulness and curiosity to avoid complacency. The author concludes that while experience is valuable, it must be coupled with a desire to learn and understand in order to develop true expertise. [Extracted from the article]

This article discusses the incidence of avalanche accidents and the usage and effectiveness of practices in prevention and safety. The authors comment on the conclusions of a recent review, stating that official statistics do not support the claim that there has been an increase in avalanche fatalities during the COVID-19 pandemic. They also highlight the variability in the rate of usage of avalanche airbags and other safety equipment, citing different studies with varying usage rates. The authors acknowledge that avalanche airbags can be effective in preventing critical burial and reducing overall mortality if used correctly, but emphasize the importance of proper maintenance and user awareness. [Extracted from the article]

The Hatcher Pass Avalanche Center (HPAC) experienced a relatively dry and cold January, allowing weak layers of surface hoar and near-surface facets to form. However, these layers remained inactive until late February when natural and human-triggered avalanches occurred. Avalanches breaking on persistent weak layers became deeper and more destructive through April. The winter of 2022-2023 in Hatcher Pass saw fewer avalanche incidents and accidents overall compared to previous years. HPAC provided avalanche advisories and published announcements throughout the season, and their avalanche education program reached over 1000 local high school students. [Extracted from the article]

Introduction: We aimed to investigate the relationship between the time of the day and the probability of survival of completely buried avalanche victims. We explored the frequency of avalanche burials occurring after sunset, and described victims' characteristics, duration of burial and rescue circumstances compared to daytime avalanches.Methods: In this retrospective, observational study, we analysed avalanche data from the registry of the Swiss Institute for Snow and Avalanche Research, from 1998 to 2020.Results: A total of 3892 avalanche victims were included in the analysis, with 72 of the accidents (1.85%) occurring in the nighttime. Nearly 50% of the victims involved in nighttime avalanche accidents were completely buried, compared to about 25% of victims in daytime avalanches. Completely buried victims were rescued by a companion less often at night than in the daytime (15% vs. 51%, p <.001). The search and rescue of completely buried avalanche victims took longer during the nighttime compared to the daytime (median 89 min vs 20 min, p =.002). The probability of survival decreased as the day progressed; it was highest at around midday (63.0%), but decreased at sunset (40.4%) and was the lowest at midnight (28.7%).Conclusions: Avalanche accidents at night are a rare event, and probability of survival after complete burial is lower during the nighttime compared to the daytime. The most relevant reason for this is the longer duration of burial, which is explained in part by the lower rate of companion rescue and the lower rate of victim localisation with an avalanche transceiver. [ABSTRACT FROM AUTHOR]

According to the living data process in ESSD, this publication presents extensions of a comprehensive hydrometeorological and glaciological data set for several research sites in the Rofental (1891-3772 m a.s.l., Ötztal Alps, Austria). Whereas the original dataset has been published in a first original version in 2018 (https://doi.org/10.5194/essd-10-151-2018), the new time series presented here originate from meteorological and snow-hydrological recordings that have been collected from 2017 to 2020. Some data sets represent continuations of time series at existing locations, others come from new installations complementing the scientific monitoring infrastructure in the research catchment. Main extensions are a fully equipped automatic weather and snow monitoring station, as well as extensive additional installations to enable continuous observation of snow cover properties. Installed at three high Alpine locations in the catchment, these include automatic measurements of snow depth, snow water equivalent, volumetric solid and liquid water content, snow density, layered snow temperature profiles, and snow surface temperature. One station is extended by a particular arrangement of two snow depth and water equivalent recording devices to observe and quantify wind-driven snow redistribution. They are installed at nearby wind-exposed and sheltered locations and are complemented by an acoustic-based snow drift sensor. The data sets represent a unique time series of high-altitude mountain snow and meteorology observations. We present three years of data for temperature, precipitation, humidity, wind speed, and radiation fluxes from three meteorological stations. The continuous snow measurements are explored by combined analyses of meteorological and snow data to show typical seasonal snow cover characteristics. The potential of the snow drift observations are demonstrated with examples of measured wind speeds, snow drift rates and redistributed snow amounts in December 2019 when a tragic avalanche accident occurred in the vicinity of the station. All new data sets are provided to the scientific community according to the Creative Commons Attribution License by means of the PANGAEA repository (https://www.pangaea.de/?q=%40ref104365). [ABSTRACT FROM AUTHOR]

Avalanches are major natural hazards in snow-covered mountains, threatening people and infrastructure. With ongoing climate change, the frequency and types of snow avalanches may change, affecting the rates of avalanche burial and survival. With a wetter and warmer snow climate, consequences of burial may become more severe. In this review, we assess the potential effects of climate change on the frequency and characteristics of avalanches. We then discuss how these changes might affect the survival rates of subjects buried by avalanches and might influence the responses of search and rescue (SAR) teams and health care providers. While climate change is inevitable, the effects on avalanches remain elusive. The frequency of human triggered avalanches may not change, because this depends largely on the number and behavior of winter recreationists. Blunt trauma and secondary injuries will likely become more frequent as terrain roughness is expected to rise and snow cover to become thinner. Higher snow densities in avalanche debris will likely interfere with the respiration of completely buried victims. Asphyxia and trauma, as causes of avalanche death, may increase. It is unlikely that SAR and health care providers involved in avalanche rescue will have to change their strategies in areas where they are already established. The effects of climate change might foster the expansion of mitigation strategies and the establishment of mountain rescue services in areas subject to increased avalanche hazards caused by changes in snow cover and land use. [ABSTRACT FROM AUTHOR]

The Colorado Avalanche Information Center (CAIC) is celebrating its 50th anniversary of providing avalanche forecasting and safety information. The organization began in 1973 as the Colorado Avalanche Warning Program and has since grown to have 31 staff members. Over the years, CAIC has evolved its forecasting model and now issues daily forecasts for dynamic zones, allowing forecasters to highlight areas with similar avalanche conditions. CAIC also shares its information through various channels, including email newsletters and its website. The organization has been housed within different agencies and programs, currently residing within the Colorado Department of Natural Resources. CAIC has played a significant role in advancing snow science and has been involved in research on avalanche and accident patterns. Additionally, CAIC joined the Colorado Department of Transportation's highway safety program in 1993 to provide avalanche forecasting for highways. [Extracted from the article]

Avalanches represent the primary risk of death to backcountry skiers and snowmobilers in North American and European alpine countries. The best strategy for evading dangerous snowpack conditions that may result in an avalanche event requires skiers and snowmobilers to avoid or mitigate their use of hazardous terrain. Therefore, understanding terrain use is critical to understanding the causes of avalanche accidents. Secondary, post-event examination of accident data is inadequate for this understanding, and the logistical costs of user intercept surveys are problematic. Learning more about the behaviors and practices skiers and snowmobilers use to avoid avalanche fatalities or near misses is the primary concern of the avalanche education and research community. However, the topographical data required for analysis of skier and snowmobiler behavior with respect to terrain use is beyond the capacity of most backcountry skiers to provide via traditional surveys. This paper presents the use of a novel combination of user surveys and Global Positioning System (GPS) tracking to collect detailed terrain-use data from recreationists who voluntarily engage with researchers via active participation in citizen science research projects. We describe the methodology for these observations and present why they represent an effective approach to understand avalanche accidents. [ABSTRACT FROM AUTHOR]

This paper will review the emergence and adoption of decision heuristics as a conceptual framework within the avalanche research and education community and demonstrate how this emphasis on the heuristic decision framework has anchored and was critical in redefining the discussion around avalanche accidents. This paradigm has been a critical and meaningful step in recognizing the importance of decision making in avalanche accidents. However, in an attempt to reduce the incidence of fatal accidents, the adoption of these ideas within the wider avalanche community has overlooked some clearly stated limitations within the foundational work of the heuristic decision frame. With respect to the concept of heuristic traps in conventional avalanche education, the concepts are poorly operationalized to the extent that they are vague about what exactly they describe. The result is that as presently framed, they are of negligible value to avalanche education that seeks its basis on the best available information. We end with a discussion, and a call to action to the avalanche research community, of how we could move towards resolution of these weaknesses and add value to prior work on human factor research. Our aim is not to disparage the seminal, paradigm shifting work by McCammon, but rather draw attention to how it has been operationalized and how the industry needs to move beyond this paradigm to see further gains in our understanding of avalanche fatalities.

Objectives: More than 20 people die each year in snow avalanches in Switzerland. Previous studies have primarily described these victims, but were not population based. We investigated sociodemographic factors for avalanche mortality between 1995 and 2014 in the entire Swiss resident population. Design and methods: Within the Swiss National Cohort we ascertained avalanche deaths by anonymous data linkage with the avalanche accident database at the Swiss WSL Institute of Snow and Avalanche Research SLF. We calculated incidence rates, by dividing the number of deaths from avalanches by the number of person-years, and hazard ratios (HRs) for sociodemographic and economic characteristics using Cox proportional hazard models. Results: The data linkage yielded 250 deaths from avalanche within the SNC population for the 20 years 1995 to 2014. The median distance between the place of residence and the place of the event (avalanche) was 61.1 km. Male gender, younger age (15–45 years), Swiss nationality, living in the Alpine regions, higher education, living in the highest socioeconomic quintile of neighbourhoods, being single, and living in a household with one or more children were associated with higher avalanche mortality rates. Furthermore, for younger persons (<40 years) the hazard of dying in an avalanche between 2005 and 2014 was significantly lower than in the years 1995 to 2004 (HR = 0.56, 95%-CI: 0.36–0.85). Conclusion: Over a 20-year period in Switzerland, higher rates of dying in an avalanche were observed in men, in younger age groups, and persons with tertiary education, living in the highest socioeconomic quintile of neighbourhoods, and living in an Alpine region. For younger persons (<40 years), the hazard declined during the study period. [ABSTRACT FROM AUTHOR]

Overconfidence is a well-established bias in which someone's subjective confidence in their own judgment is systematically greater than their objective accuracy. There is abundant anecdotal evidence that overconfident people increase their exposure to risk. In this paper, we test whether overconfident backcountry skiers underestimate the probability of incurring a snow avalanche accident. An avalanche accident is a typical "black swan" event as defined by Taleb (The black swan: the impact of the highly improbable, Random House, New York, 2007) because it has a very low probability of occurring but with potentially dramatic consequences. To consider black swan events when studying overconfidence is particularly important, in light of previous findings on the role of overconfidence when feedbacks on tasks previously performed are inconclusive and infrequent. We run our test by measuring individual overconfidence using standard tools from the literature and then use a random effect logit model to measure its effect on the probability to take the ski route. We show that (1) overconfidence is widespread in our sample; (2) practitioners who are more prone to overestimate their knowledge are also more likely to take risks associated with a ski trip under the threat of avalanche danger, a result robust to a set of specification tests we perform. This suggests that overconfident people are more exposed to black swan events, by taking a risky decision that can bring about fatal consequences. [ABSTRACT FROM AUTHOR]

Abstract A large catastrophic rock avalanche with a total volume of ~18.0 × 106 m3 occurred at 5:38 am, 24th June 2017, at Xinmo Village, Maoxian, Sichuan, China, resulting in 102 casualties (10 deaths, 3 injuries, and 89 missing). We have been conducting a geological and geomorphological investigation in and around the Xinmo landslide site since 2015, and we present our results here, including data obtained before and after the landslide event. The landslide, which had an initial volume of 4.46 × 106 m3 of its source area, was induced by rainfall on a previous landslide scar near the ridge top. This initial landslide then struck and remobilized older landslide deposits in the middle and lower parts of the slope, which subsequently buried Xinmo Village at the landslide toe. The landslide occurred on a dip slope of Triassic calcareous psammitic and pelitic schists. The bedding plane, which dips downslope to the south with an orientation of N80°W/48°S, and high-angle NE–SW striking joints bounded the landslide source area at its base and sides, respectively. Satellite image analysis and field observations of the slope of the landslide scar before and after the landslide strongly suggest that the beds in the source area had already begun gravitationally deforming (e.g., buckling) prior to the 2017 landslide. Moreover, pits on the slip surface were likely the result of the dissolution of calcareous material. Dissolution probably reduced the rock strength along the bedding plane. A rainfall event from the 16th to 24th of June 2017 probably dominated the groundwater drainage, and finally triggered the catastrophic rock avalanche. In addition to the 2017 landslide, the hillslope just to the east of the Xinmo landslide exhibits pronounced gravitational slope deformation, including "A-tent"-like structures and warps induced by buckling. This suggests that this slope could also fail like the Xinmo rock avalanche during a future rainfall or earthquake event. Highlights • Geological and geomorphological features of the Xinmo landslide were characterized. • Geological structures generated by buckling existed prior to the landslide. • A stability evaluation indicates that the buckling preceded the landslide. • The landslide was probably induced by pore pressure buildup due to rainfall. • A slope near the landslide has been gravitationally deformed and is prepared to fail. [ABSTRACT FROM AUTHOR]

An avalanche accident was occurred on 5 January 2018 on Chowkibal--Tangdhar road in Kupwara district, Jammu and Kashmir about 6 km from Chowkibal village. One light passenger vehicle was swept away in the avalanche and 10 persons lost their lives. In this communication, we study the cause of avalanche accident and simulate the snow avalanche flow using Rapid Mass MovementS model. Total snow depth recorded at the nearest observation location from the accident site was 31 cm and fresh snow of the storm was 24 cm. Avalanche condition on slope was building up and the Snow and Avalanche Study Establishment issued an avalanche warning of 'Low Danger' for the Chokibal--Tangdhar road axis. Maximum thickness of avalanche debris on road was observed to be 3.0 m. Flow simulation showed maximum velocity of avalanche to be ~25 ms-1, maximum impact pressure ~9.39 x 104 kg m-1 s-2 and maximum height of avalanche flow ~3.0 m. [ABSTRACT FROM AUTHOR]

Deaths due to avalanches have a significant mortality burden in Western Canada. The aim of this review is to summarize risk factors, causes of death, and important mitigation and management strategies in treating avalanche victims. Multiple risk factors for avalanches have been identified, which relate to both physical characteristics of the avalanche environment as well as human factors. Winter backcountry recreationists should be mindful of their motivations for exposing themselves to avalanche dangers and remain objective to the physical characteristics conferring avalanche accident risk. Asphyxia is responsible for the vast majority of deaths due to avalanche, while trauma remains an important cause in certain geographic areas. Avalanche training courses educate learners on avalanche rescue sequences, which utilize avalanche transceivers, probes, and strategic shoveling techniques. The primary goal of rescue is to reduce the median time of burial, thereby decreasing the incidence of asphyxia and ultimately, death. Following the extrication of an individual from an avalanche, rescuers may have to begin resuscitation efforts. Future developments in avalanche safety should focus on public education of avalanche risk factors, incorporation of basic life support into avalanche training courses, and further development of technologies that may increase survivability. [ABSTRACT FROM AUTHOR]

Introduction: To explore baseline knowledge about avalanche guidelines and the Avalanche Victim Resuscitation Checklist (AVReCh) in Italy and the knowledge acquisition from a standardized lecture.Methods: Standardized lecture material discussing AVReCh was presented during 8 mountain medicine courses from November 2014 to April 2016 in different regions of Italy. To determine the knowledge acquisition from the lecture, a pre- and postlecture survey was utilized.Results: A total of 193 surveys were analyzed. More than 50% of the participants had never participated in lectures/courses on avalanche guidelines, and less than 50% of the participants knew about the AVReCh before the lecture. The correct temporal sequence of reportable information in the basic life support section of the AVReCh was selected by 40% of the participants before the lecture and by 75% after the lecture (P<0.001). Within subgroups analysis, most groups saw significant improvement in performance (P<0.05). The selection of the correct burial time increased from 36 to 84% (P<0.05).Conclusions: Health care providers and mountain rescue personnel are not widely aware of avalanche guidelines. The standardized lecture significantly improved knowledge of the principles of avalanche management related to core AVReCh elements. However, the effect that this knowledge acquisition has on avalanche victim survival or adherence to the AVReCh in the field is yet to be determined. [ABSTRACT FROM AUTHOR]

We study how short duration powder avalanche blasts can break and overturn tall trees. Tree blow-down is often used to back-calculate avalanche pressure and therefore constrain avalanche flow velocity and motion. We find that tall trees are susceptible to avalanche air blasts because the duration of the air blast is near to the period of vibration of tall trees, both in bending and root-plate overturning. Dynamic magnification factors for bending and overturning failures should therefore be considered when back-calculating avalanche impact pressures. [ABSTRACT FROM AUTHOR]

In this article we analyzed spatial and temporal patterns of fatal Austrian avalanche accidents caused by backcountry and off-piste skiers and snowboarders within the winter periods 1967/1968-2015/2016. The data were based on reports of the Austrian Board for Alpine Safety and reports of the information services of the federal states. Using the date and the location of the recorded avalanche accidents, we were able to carry out spatial and temporal analyses applying generalized additive models and Markov random-field models. As a result of the trend analysis we noticed an increasing trend of backcountry and off-piste avalanche fatalities within the winter periods 1967/1968-2015/2016 (although slightly decreasing in recent years), which is in contradiction to the widespread opinion in Austria that the number of fatalities is constant over time. Additionally, we compared Austrian results with results of Switzerland, France, Italy and the US based on data from the International Commission of Alpine Rescue (ICAR). As a result of the spatial analysis, we noticed two hot spots of avalanche fatalities ("Arlberg-Silvretta" and "Sölden"). Because of the increasing trend and the rather "narrow" regional distribution of the fatalities, initiatives aimed at preventing avalanche accidents were highly recommended. [ABSTRACT FROM AUTHOR]

Recent technical and strategical developments have increased the survival chances for avalanche victims. Still hundreds of people, primarily recreationists, get caught and buried by snow avalanches every year. About 100 die each year in the European Alps–and many more worldwide. Refining concepts for avalanche rescue means to optimize the procedures such that the survival chances are maximized in order to save the greatest possible number of lives. Avalanche rescue includes several parameters related to terrain, natural hazards, the people affected by the event, the rescuers, and the applied search and rescue equipment. The numerous parameters and their complex interaction make it unrealistic for a rescuer to take, in the urgency of the situation, the best possible decisions without clearly structured, easily applicable decision support systems. In order to analyse which measures lead to the best possible survival outcome in the complex environment of an avalanche accident, we present a numerical approach, namely a Monte Carlo simulation. We demonstrate the application of Monte Carlo simulations for two typical, yet tricky questions in avalanche rescue: (1) calculating how deep one should probe in the first passage of a probe line depending on search area, and (2) determining for how long resuscitation should be performed on a specific patient while others are still buried. In both cases, we demonstrate that optimized strategies can be calculated with the Monte Carlo method, provided that the necessary input data are available. Our Monte Carlo simulations also suggest that with a strict focus on the "greatest good for the greatest number", today's rescue strategies can be further optimized in the best interest of patients involved in an avalanche accident. [ABSTRACT FROM AUTHOR]

The present study investigated how information about situational characteristics typically encountered by backcountry recreationists influenced their perceived likelihood of skiing backcountry slopes exposed to avalanche danger. Sensation seeking and previous direct and indirect experiences with avalanche accidents were evaluated as relevant individual predictors. Data was collected by implementing randomized textual scenarios, using a sample of 376 backcountry recreationists from North-Italy (84% male; age: M = 39.68, SD = 9.72). Results of multilevel analyses indicated that forecasted avalanche danger level and slope inclination were associated with lower self-reported likelihood of skiing the slopes, while sensation-seeking, familiarity with the slope area, the availability of safety equipment and the presence of tracks on the slope were positively related with selfreported likelihood of skiing. Previous direct involvement in avalanche accidents was also positively associated with perceived likelihood of skiing, suggesting the existence of confidence-enhancing effects related to avalanche survival experiences. [ABSTRACT FROM AUTHOR]

In Europe and North America, approximately 150 fatalities occur as a result of avalanches every year. However, it is unclear whether certain shovel shapes are more effective than others in snow removal during avalanche victim recovery. The objective was to determine the performance parameters with a developed standardized test using different shovel shapes and to determine sex-specific differences. Hence, several parameters were determined for clearing the snow from a snow filled box (15 men, 14 women). A flat (F) and a deep (D) shovel blade with the shaft connected straight (S) or in clearing mode (C) were used for the investigation of the shovel shapes FS, DC and the subsequent use of DC&DS. Mean snow mass shifted per unit time increased significantly from 1.50 kg/s with FS to 1.71 kg/s (14%) with DS and further to 1.79 kg/s (4%) with DC&DS for all participants. Snow mass shifted per unit time was 44% higher (p < 0.05) for men than for women. In excavation operations, the sex-specific physical performance should be taken into account. The results were limited to barely binding snow, because only with this snow did the tests show a high reliability. [ABSTRACT FROM AUTHOR]

Pasquier, Mathieu, Olivier Hugli, Alexandre Kottmann, and Frank Techel. Avalanche accidents causing fatalities: are they any different in the summer? High Alt Med Biol. 18:67-72, 2017. Aims: This retrospective study investigated the epidemiology of summer avalanche accidents that occurred in Switzerland and caused at least one fatality between 1984 and 2014. Summer avalanche accidents were defined as those that occurred between June 1st and October 31st. Results: Summer avalanches caused 21 (4%) of the 482 avalanches with at least one fatality occurring during the study period, and 40 (6%) of the 655 fatalities. The number of completely buried victims per avalanche and the proportion of complete burials among trapped people were lower in summer than in winter. Nevertheless, the mean number of fatalities per avalanche was higher in summer than in winter: 1.9 ± 1.2 (standard deviation; range 1-6) versus 1.3 ± 0.9 (range 1-7; p < 0.001). Trauma was the presumed cause of death in 94% (33 of 35) in summer avalanche accidents. Sixty-five percent of fully buried were found due to visual clues at the snow surface. Conclusions: Fatal summer avalanche accidents caused a higher mean number of fatalities per avalanche than winter avalanches, and those deaths resulted mostly from trauma. Rescue teams should anticipate managing polytrauma for victims in summer avalanche accidents rather than hypothermia or asphyxia; they should be trained in prehospital trauma life support and equipped accordingly to ensure efficient patient care. [ABSTRACT FROM AUTHOR]

To provide guidance to clinicians and avalanche professionals about best practices, the Wilderness Medical Society convened an expert panel to develop evidence-based guidelines for the prevention, rescue, and medical management of avalanche and nonavalanche snow burial victims. Recommendations are graded on the basis of quality of supporting evidence according to the classification scheme of the American College of Chest Physicians. [ABSTRACT FROM AUTHOR]

Following an avalanche, one of the factors that affect victims' chance of survival is the speed with which they are located and dug out. Rescue teams use techniques like trained rescue dogs and electronic transceivers to locate victims. However, the resources and time required to deploy rescue teams are major bottlenecks that decrease a victim's chance of survival. Advances in the field of Unmanned Aerial Vehicles (UAVs) have enabled the use of flying robots equipped with sensors like optical cameras to assess the damage caused by natural or manmade disasters and locate victims in the debris. In this paper, we propose assisting avalanche search and rescue (SAR) operations with UAVs fitted with vision cameras. The sequence of images of the avalanche debris captured by the UAV is processed with a pre-trained Convolutional Neural Network (CNN) to extract discriminative features. A trained linear Support Vector Machine (SVM) is integrated at the top of the CNN to detect objects of interest. Moreover, we introduce a pre-processing method to increase the detection rate and a post-processing method based on a Hidden Markov Model to improve the prediction performance of the classifier. Experimental results conducted on two different datasets at different levels of resolution show that the detection performance increases with an increase in resolution, while the computation time increases. Additionally, they also suggest that a significant decrease in processing time can be achieved thanks to the pre-processing step. [ABSTRACT FROM AUTHOR]

The aim of studies was to summarize all available published records of snow avalanche events in the Tatra Mountains in a form of a geodatabase and assess the usefulness of compiled information for analyses of long-term changes in snow avalanches characteristics. The systematic study of various sources from Poland and Slovakia resulted in geodatabase including about 3406 avalanche events, of which 2033 were registered in the Polish and 1373 in the Slovakian parts of the Tatra Mountains. The geodatabase comprises information about location, type and size of the avalanche, time of the event, source of the information as well as information about rescue missions, number of injured and fatalities. The snow avalanches causing the accidents are well documented. The rest of the avalanches were registered only as a result of the researches lasting from one up to maximum 11 winters or sporadic observations. In the Polish part of the High Tatra Mountains most of the avalanches were reported (681 events) in the Białka Valley, especially the Mięguszowieckie Szczyty ridge. In the Slovakian part of the Tatra Mountains most of the records came from the Žiarska Valley (222 events), especially the Tri kopy ridge. Although the records are unsystematic, the collected information can be used, if processed with caution, to analyse the certain aspects of the avalanche activities. The geodatabase was designed and developed in the way that allows future improvements by adding new records, either recent or historical ones. [ABSTRACT FROM AUTHOR]

Aim: To calculate the first Austrian avalanche survival curve and update a Swiss survival curve to explore survival patterns in the Alps.Methods: Avalanche accidents occurring between 2005/06 and 2012/13 in Austria and Switzerland were collected. Completely buried victims (i.e. burial of the head and chest) in open terrain with known outcome (survived or not survived) were included in the analysis. Extrication and survival curves were calculated using the Turnbull algorithm, as in previous studies.Results: 633 of the 796 completely buried victims were included (Austria n=333, Switzerland n=300). Overall survival was 56% (Austria 59%; Switzerland 52%; p=0.065). Time to extrication was shorter in Austria for victims buried ≤60min (p<0.001). The survival curves were similar and showed a rapid initial drop in survival probability and a second drop to 25-28% survival probability after burial duration of ca. 35min, where an inflection point exists and the curve levels off. In a logistic regression analysis, both duration of burial and burial depth had an independent effect on survival. Victims with an air pocket were more likely to survive, especially if buried >15min.Conclusion: The survival curves resembled those previously published and support the idea that underlying survival patterns are reproducible. The results are in accordance with current recommendations for management of avalanche victims and serve as a reminder that expedient companion rescue within a few minutes is critical for survival. An air pocket was shown to be a positive prognostic factor for survival. [ABSTRACT FROM AUTHOR]

Avalanche mitigation routinely uses explosives to both initiate avalanches and test slope stability. This project aimed to verify past findings and further develop an understanding of explosive shockwave interactions with hard and soft slab conditions within 2-5 m of the detonation. Pentolite cast boosters (0.9 and 0.45 kg) were detonated at 0.0, 0.5, 1.0, 1.5, and 2.0 m above the snow. Six orthogonally paired accelerometers inserted into the snowpack recorded snow accelerations. High-pressure sensors located at and above the snow surface measured air overpressures. Distances were scaled to trinitrotoluene (TNT) equivalents to aid in explosive placement comparisons. A substantial advantage was recorded in snow accelerations attributable to elevating explosives above the snow surface. Elevating charges not only increased overall response, but also increased the effective range and depth with no penalty in shock attenuation rates. Using attenuation relationships, a method for predicting the maximum range and affected volume for a specified acceleration value was developed. Field data showed the importance of explosive placement and how the affected volume, and thereby the probability of artificial avalanche release, can be greatly increased. [ABSTRACT FROM AUTHOR]