Temporal Changes in the Spatial Variablility of Snow Stability

雪崩是美国西部山区和世界各地高山地区的重大灾害。 了解积雪稳定性和积雪特性的空间变化对于理解和预测雪崩至关重要。 虽然以前的研究已经调查了单个斜坡的空间变异性，但大多数研究只是简单地观察了一个极其动态系统的单一快照。 该项目试图通过测量和分析积雪特性和雪稳定性的空间变异性如何随时间变化来填补这一基础知识的空白。 关于这一主题的初步工作表明，雪稳定性在给定的斜坡上可能会发散或变得更加空间可变随着时间的推移，积雪稳定在没有外部影响。 然而，如果一个斜坡被扰动到不稳定的边缘，雪的稳定性可能会收敛或变得更加空间均匀。 这项研究将利用瑞士联邦雪和雪崩研究所和美国陆军寒冷地区工程实验室共同开发的一种新的雪稳定性测试和一种灵敏的仪器来测量雪稳定性的时间变化。 相邻的900平方米的地块将在不同的现场进行采样。 数据分析将集中在雪坑中测量的雪稳定性如何代表各自图的平均值以及弱层厚度，强度和微观结构的空间模式如何随时间变化。拟议的研究将解决雪崩研究和预测的紧迫问题，并为科学家提供有关积雪如何演变和雪崩如何释放的新的重要信息。 在实践层面上，这项工作将为雪崩专业人员提供至关重要的相关见解，以保护生命和财产。 这项研究的结果将提高雪崩预报的技术。 研究结果还将改善雪崩缓解工作，保护滑雪区和高速公路走廊。 最后，这项工作将造福社会，为所有在山区环境中玩耍、工作、生活和旅行的人提供重要的新信息。

Snow avalanches are a significant hazard in the mountainous environments of the western United States and in alpine regions around the world. Knowledge of spatial variations in snow stability and snowpack properties is critical for understanding and predicting snow avalanches. Although previous research has investigated spatial variability on individual slopes, most studies have simply looked at a single snapshot in time of an extremely dynamic system. This project attempts to fill this gap in fundamental knowledge by measuring and analyzing how the spatial variability of snowpack properties and snow stability vary through time. Preliminary work on this topic suggests that snow stability on a given slope may diverge or become more spatially variable over time as the snowpack stabilizes in the absence of external influences. If a slope is perturbed to the edge of instability, however, the snow stability may converge or become more spatially uniform. This study will utilize a new snow stability test and a sensitive instrument co-developed by the Swiss Federal Institute for Snow and Avalanche Research and the U.S. Army Cold Regions Engineering Laboratory to measure temporal changes in snow stability. Adjacent 900-square meter plots will be sampled through time at variety of field sites. Data analyses will focus on how well snow stability measured in snowpits represents the mean of their respective plot and how spatial patterns of weak layer thickness, strength, and microstructure change through time.The proposed research will address a pressing question for snow avalanche research and prediction, and it will offer new and important information for scientists about how the snowpack evolves and how avalanches release. On a practical level, the work will provide critically relevant insights for avalanche professionals working to protect life and property. The results of this research will enhance techniques for avalanche forecasting. The results also will improve avalanche mitigation efforts that protect ski areas and highway corridors. Finally, this work will benefit society by providing important new information for all people playing in, working in, living in, and traveling through mountain environments.