Item: Monitoring Snow Cornice Development Using Time-Lapse Photography
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Title: Monitoring Snow Cornice Development Using Time-Lapse Photography
Proceedings: International Snow Science Workshop 2014 Proceedings, Banff, Canada
Authors:
- Alec van Herwijnen [ WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland ]
- Charles Fierz [ WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland ]
Date: 2014-09-29
Abstract: A snow cornice is an overhanging mass of snow which generally forms on the lee side of ridges. Cornices can present a substantial snow avalanche hazard as they can trigger avalanches when they break. While the hazard posed by cornices has long been recognized and they are extensively controlled in avalanche operations, little research exists on cornice formation and failure. In this study, we used a time-lapse camera to monitor the growth and failure of a cornice during the 2013-2014 season. Images were taken at five minute intervals at a site which is instrumented with several automatic weather stations above the town of Davos, Switzerland. To compare the growth of the cornice with local meteorological variables, we developed a method to automatically track the horizontal extent of the cornice based on converting the images to a binary format. Our results show that cornice growth only occurred during periods of moderate to high winds during or soon after snowfall. During the season we only observed a few small cornice failures, which mainly occurred after periods of rapid cornice growth. Finally, we compared our observed cornice extent to the wind drift index calculated by the snow cover model SNOW-PACK. The agreement between both was remarkable, suggesting that the SNOWPACK wind drift index can be used to quantify regional cornice growth.
Language of Article: English
Presenters:
Keywords: cornice growth, snow cover modeling, time-lapse photography, avalanche forecasting.
Page Number(s): 909-913
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Digital Abstract Not Available
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