Scholarly Work - Earth Sciences
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Item Perceptions Among Backcountry Skiers During the COVID-19 Pandemic: Avalanche Safety and Backcountry Habits of New and Established Skiers(Elsevier BV, 2022-12) Valle, Esteban A.; Cobourn, Andrew P.; Trivitt, Spencer JH.; Hendrikx, Jordy; Johnson, Jerry D.; Fiore, David C.Introduction.The coronavirus disease 2019 (COVID-19) pandemic impacted the ski industry worldwide by closing or limiting access to ski resorts. Subsequently, anecdotal reports of increased backcountry use emerged in the press, with concerns of inexperienced skiers causing or having problems in the backcountry. This study attempted to quantify this and identify motivations for new backcountry skiers. Methods. Self-identified backcountry skiers and snowboarders (aged ≥18 y) in the United States and Canada completed an anonymous 29-question online survey distributed by regional avalanche centers, education providers, and skiing organizations (n=4792). Respondents were stratified by backcountry experience, defining “newcomers” who began backcountry skiing from 2019 to 2021, coincident with the COVID-19 pandemic. Percentages of ski days spent in the backcountry were compared before and during the COVID-19 pandemic using paired t-tests and across cohorts using repeated-measures analysis of variance. Avalanche education was compared using unpaired χ2 tests. Results. Of established skiers, 81% noticed more people in the backcountry and 27% reported increasing their own use. Participants reported spending 17% (95% CI, 15.8–17.9) more of their days in the backcountry during the COVID-19 pandemic, with newcomers increasing their time spent by 36% and established skiers increasing their time spent by 13% (P<0.0001). Of newcomers, 27% cited the COVID-19 pandemic as motivation to enter the backcountry and 24% lacked formal avalanche education, which is significantly higher than the 14% of established skiers (P<0.0001). Conclusions. Influenced by factors related to COVID-19, reported backcountry use increased during the pandemic. Newcomers had a lower level of avalanche education and less confidence in evaluating terrain. Because 80% of participants were recruited from avalanche safety or education websites, this likely underestimates skiers lacking avalanche awareness or education and is further limited by the nature of online surveys.Item Perceptions Among Backcountry Skiers During the COVID-19 Pandemic: Avalanche Safety and Backcountry Habits of New and Established Skiers(Elsevier BV, 2022-12) Valle, Esteban A.; Cobourn, Andrew P.; Trivitt, Spencer JH.; Hendrikx, Jordy; Johnson, Jerry D.; Fiore, David C.Introduction. The coronavirus disease 2019 (COVID-19) pandemic impacted the ski industry worldwide by closing or limiting access to ski resorts. Subsequently, anecdotal reports of increased backcountry use emerged in the press, with concerns of inexperienced skiers causing or having problems in the backcountry. This study attempted to quantify this and identify motivations for new backcountry skiers. Methods. Self-identified backcountry skiers and snowboarders (aged ≥18 y) in the United States and Canada completed an anonymous29-question online survey distributed by regional avalanche centers, education providers, and skiing organizations (n=4792). Respondents were stratified by backcountry experience, defining “newcomers” who began backcountry skiing from 2019 to 2021, coincident with the COVID-19 pandemic. Percentages of ski days spent in the backcountry were compared before and during the COVID-19 pandemic using paired t-tests and across cohorts using repeated-measures analysis of variance. Avalanche education was compared using unpaired χ2 tests. Results. Of established skiers, 81% noticed more people in the backcountry and 27% reported increasing their own use. Participants reported spending 17% (95% CI, 15.8–17.9) more of their days in the backcountry during the COVID-19 pandemic, with newcomers increasing their time spent by 36% and established skiers increasing their time spent by 13% (P<0.0001). Of newcomers, 27% cited the COVID-19 pandemic as motivation to enter the backcountry and 24% lacked formal avalanche education, which is significantly higher than the 14% of established skiers (P<0.0001). Conclusions. Influenced by factors related to COVID-19, reported backcountry use increased during the pandemic. Newcomers had a lower level of avalanche education and less confidence in evaluating terrain. Because 80% of participants were recruited from avalanche safety or education websites, this likely underestimates skiers lacking avalanche awareness or education and is further limited by the nature of online surveys.Item Satellite detection of snow avalanches using Sentinel-1 in a transitional snow climate(Elsevier BV, 2022-07) Keskinen, Zachary; Hendrikx, Jordy; Eckerstorfer, MarkusSnow avalanches endanger lives and infrastructure in mountainous regions worldwide. Consistent and accurate datasets of avalanche events are critical for improving hazard forecasting and understanding the spatial and temporal patterns of avalanche activity. Remote sensing-based identification of avalanche debris allow for the acquisition of continuous and spatially consistent avalanches datasets. This study utilizes expert manual interpretations of Sentinel-1 synthetic aperture radar (SAR) satellite backscatter images to identify avalanche debris and compares those detections against historical field records of observed avalanches in the transitional snow climates of Wyoming and Utah, USA. We explore and quantify the ability of an expert using Sentinel-1 (a SAR satellite) images to detect avalanche debris on a dataset comprised exclusively of dry slab avalanches. This research utilized four avalanche cycles with 258 field reported avalanches. Due to individual avalanches appearing in multiple overlapping Sentinel-1 images this resulted in 506 potential detections of avalanches in our SAR images, representing the possibility of multiple detections of a single avalanche event in different images. The overall probability of detection (POD) for avalanches large enough to destroy trees or bury a car (i.e., ≥D3 on the destructive size scale) was 65%. There was a significant variance in the POD among the 13 individual SAR image pairs considered (15–86%). Additionally, this study investigated the connection between successful avalanche detections and SAR-specific, topographic, and avalanche type variables. The most correlated variables with higher detection rates were avalanche path lengths, destructive size of the avalanche, incidence angles for the incoming microwaves, average path slope angle, and elapsed time between the avalanche and a Sentinel-1 satellite image acquisition. This study provides a quantification of the controlling variables in the likelihood of detecting avalanches using Sentinel-1 backscatter temporal change detection techniques, as specifically applied to a transitional snow climate.Item Colours and maps for communicating natural hazards to users with and without colour vision deficiency(Elsevier BV, 2022-06) Engeset, Rune Verpe; Pfuhl, Gerit; Orten, Camilla; Hendrikx, Jordy; Hetland, AudunNatural hazards are often communicated visually using colours and maps. However, users' ability to read and understand these products may be hampered by e.g., colour vision deficiency, potentially rendering the products less effective or even counter effective. To study these effects, we conducted two web-based surveys and analysed how to improve visual communication of avalanches, floods, landslides, and dangerous weather hazards. In survey 1 (n = 79), we tested four traffic light colour palettes, three map legends, and three map patterns used for communicating danger levels on the Norwegian website Varsom.no, to improve accessibility for individuals with and without colour vision deficiency (CVD). In survey 2 (n = 960), we tested four versions of traffic light colour palettes on a larger and international population. Survey 2 also tested six versions of Avalanche terrain exposure scale (ATES) maps on individuals with and without CVD varying in nationality, avalanche education and familiarity with ATES. Results suggest that the colours, legends, and maps used on Varsom should be improved, and that danger levels are best communicated with the colour palette used by Meteoalarm.info – in combination with symbols to help users with CVD. This study found that the colour scheme used for ski run difficulty in Europe was efficient for use with ATES maps for participants with and without CVD and is recommended as a worldwide standard for ATES. Further studies and testing of users’ understanding are recommended to improve clarity of danger level maps and to improve visualization of ATES classes 0 and 1 on maps. Our studies show the hidden potential for efficient and inclusive communication of natural hazards and highlights the importance of including the needs of CVD users in standardisation efforts.Item Tracking decision-making of backcountry users using GPS tracks and participant surveys(Elsevier BV, 2022-07) Hendrikx, Jordy; Johnson, Jerry; Mannberg, AndreaSnow avalanches are a significant natural hazard representing the primary risk of death to backcountry travelers in many alpine countries. Careful use of backcountry terrain through effective decision making can mitigate the risk of dangerous snowpack conditions, but requires relevant knowledge and experience. We present the results from a large-scale crowd sourced data collection method from backcountry users. Using GPS tracking via a smartphone application, coupled with online surveys, we investigate the intersection of geographical complexity, backcountry experience, demographics and behavioral biases on decision-making while navigating hazardous winter terrain. We use data from 770 GPS tracks, representing almost 1.3 million GPS points, as a geographic expression of a group's resulting decisions, and use them to quantify and understand their decision-making process. Our analysis focuses on the change in terrain use as quantified using the Avalanche Terrain Exposure Scale (ATES), and time spent in avalanche terrain, as a function of experience, avalanche hazard and other group factors. We show that self-identified experts rate themselves as significantly more skilled and also had higher levels of avalanche education. Experts also had an increased exposure to avalanche terrain overall, and also more severe terrain, as represented by median time in class 3 ATES terrain.Item Should I judge safety or danger? Perceived risk depends on the question frame.(American Psychological Association, 2021-04) Stephensen, Matthew B.; Schulze, Christin; Landrø, Markus; Hendrikx, Jordy; Hetland, AudunLinguistic polarity is a natural characteristic of judgments: Is that situation safe/dangerous? How difficult/easy was the task? Is that politician honest/dishonest? Across six studies (N = 1599), we tested how the qualitative frame of the question eliciting a risk judgment influenced risk perception and behavior intention. Using a series of hypothetical scenarios of skiing in avalanche terrain, experienced backcountry skiers judged either how safe or how dangerous each scenario was and indicated whether they would ski the scenario. Phrasing risk judgments in terms of safety elicited lower judged safety values, which in turn resulted in a lower likelihood of intending to ski the slope. The frame “safe” did not evoke a more positive assessment than the frame “danger” as might be expected under a valence-consistent or communication-driven framing effect. This seemingly paradoxical direction of the effect suggests that the question frame directed attention in a way that guided selective information sampling. Uncertainty was not required for this effect as it was observed when judging objectively safe, uncertain, and dangerous scenarios. These findings advance our theoretical understanding of framing effects and can inform the development of practices that harness question framing for applied risk perception and communication.Item Climate drivers of large magnitude snow avalanche years in the U.S. northern Rocky Mountains(Springer Science and Business Media LLC, 2021-05) Peitzsch, Erich H.; Pederson, Gregory T.; Birkeland, Karl W.; Hendrikx, Jordy; Fagre, Daniel B.Large magnitude snow avalanches pose a hazard to humans and infrastructure worldwide. Analyzing the spatiotemporal behavior of avalanches and the contributory climate factors is important for understanding historical variability in climate-avalanche relationships as well as improving avalanche forecasting. We used established dendrochronological methods to develop a long-term (1867–2019) regional avalanche chronology for the Rocky Mountains of northwest Montana using tree-rings from 647 trees exhibiting 2134 avalanche-related growth disturbances. We then used principal component analysis and a generalized linear autoregressive moving average model to examine avalanche-climate relationships. Historically, large magnitude regional avalanche years were characterized by stormy winters with positive snowpack anomalies, with avalanche years over recent decades increasingly influenced by warmer temperatures and a shallow snowpack. The amount of snowpack across the region, represented by the first principal component, is shown to be directly related to avalanche probability. Coincident with warming and regional snowpack reductions, a decline of ~ 14% (~ 2% per decade) in overall large magnitude avalanche probability is apparent through the period 1950–2017. As continued climate warming drives further regional snowpack reductions in the study region our results suggest a decreased probability of regional large magnitude avalanche frequency associated with winters characterized by large snowpacks and a potential increase in large magnitude events driven by warming temperatures and spring precipitation.Item Synoptic control on snow avalanche activity in central Spitsbergen(Copernicus GmbH, 2021-08) Hancock, Holt; Hendrikx, Jordy; Eckerstorfer, Markus; Wickström, SiiriAtmospheric circulation exerts an important control on a region's snow avalanche activity by broadly determining the mountain weather patterns that influence snowpack development and avalanche release. In central Spitsbergen, the largest island in the High Arctic Svalbard archipelago, avalanches are a common natural hazard throughout the winter months. Previous work has identified a unique snow climate reflecting the region's climatically dynamic environmental setting but has not specifically addressed the synoptic-scale control of atmospheric circulation on avalanche activity here. In this work, we investigate atmospheric circulation's control on snow avalanching in the Nordenskiöld Land region of central Spitsbergen by first constructing a four-season (2016/2017–2019/2020) regional avalanche activity record using observations available on a database used by the Norwegian Water Resources and Energy Directorate (NVE). We then analyze the synoptic atmospheric conditions on days with differing avalanche activity situations. Our results show atmospheric circulation conducive to elevated precipitation, wind speeds, and air temperatures near Svalbard are associated with increased avalanche activity in Nordenskiöld Land, but different synoptic signals exist for days characterized by dry, mixed, and wet avalanche activity. Differing upwind conditions help further explain differences in the frequency and nature of avalanche activity resulting from these various atmospheric circulation patterns. We further employ a daily atmospheric circulation calendar to help contextualize our results in the growing body of literature related to climate change in this location. This work helps expand our understanding of snow avalanches in Svalbard to a broader spatial scale and provides a basis for future work investigating the impacts of climate change on avalanche activity in Svalbard and other locations where avalanche regimes are impacted by changing climatic and synoptic conditions.Item Powder Fever and Its Impact on Decision-Making in Avalanche Terrain(MDPI AG, 2021-09) Mannberg, Andrea; Hendrikx, Jordy; Johnson, Jerry; Hetland, AudunWe examined the effect of emotions, associated with “powder fever”, on decision-making in avalanche terrain. Background: Skiing in avalanche terrain is a voluntary activity that exposes the participant to potentially fatal risk. Impaired decision-making in this context can therefore have devastating results, often with limited prior corrective feedback and learning opportunities. Previous research has suggested that arousal caused by emotions affects risk assessment and intentions to engage in risky behavior. We propose that powder fever may induce similar responses. Methods: We used the following two experimental methods: laboratory studies with visual visceral stimuli (ski movies) and a field study with real stimuli (skiing exciting terrain). We evaluated the effect of emotions on attention, risk assessment, and willingness to expose oneself and others to risk. Results: Both the laboratory studies and the field study showed that skiing-related stimuli had a relatively strong effect on reported emotions. However, we found very few significant effects on decision-making or assessment of risk. Conclusions: Skiing activities make people happier. However, despite the clear parallels to sexual arousal, powder fever does not appear to significantly impair decision-making in our study. More research on the effects of powder fewer on milder forms of risk-taking behavior is needed.Item Risky positioning – social aspirations and risk-taking behaviour in avalanche terrain(Informa UK Limited, 2020-10) Mannberg, Andrea; Hendrikx, Jordy; Johnson, JerryWe test if positionality, i.e., the desire to gain social status, is associated with an increased willingness to take risk among backcountry riders. If positional preferences drive risk-taking behaviour in avalanche terrain, this is especially problematic because the stakes are high and can be fatal. Our analysis is based on data for hypothetical choices from an online survey (N = 648) in North America. We find that positional riders are significantly more likely to boast about riding bold lines, more likely to associate steep riding with social respect, and more likely to say that they would accept to ride a potentially risky line. The positionality effect is present regardless of level of avalanche training. We discuss implications for avalanche training and education.