Item: Using Time-Lapse Photography in Avalanche Research
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Title: Using Time-Lapse Photography in Avalanche Research
Proceedings: International Snow Science Workshop Grenoble – Chamonix Mont-Blanc - October 07-11, 2013
Authors:
- Alec van Herwijnen [ WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland ]
- Nicole Berthod [ WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland ]
- Ron Simenhois [ Coeur Alaska, Juneau Alaska, USA ]
- Christoph Mitterer [ WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland ]
Date: 2013-10-07
Abstract: To improve our understanding of avalanche release processes, more accurate avalanche activity data are required. Usually, data on avalanche occurrences are obtained through visual observations from valley bottom at regular time intervals, for instance twice a day. Visual observations are not possible during periods of poor visibility, in remote locations or in hazardous situations. This results in inaccurate data and a bias towards larger avalanches, as these are more easily observed. To overcome these limitations, several remote avalanche detection methods, such as seismic or infrasonic monitoring have been developed. However, these methods can be relatively expensive and have not yet reached a level of reliability required for operational use. We propose a simple alternative using time-lapse photography. Time-lapse photography is a nonintrusive, inexpensive and safe technique that can be used to observe avalanche activity across large areas. It can also be used to measure changes in snow movement and deformation. We have used time-lapse photography to improve glide-snow avalanche forecasting by monitoring glide crack expansion. By counting the number of dark pixels in an area around a glide crack, changes in glide rates are measured. Our results show that time-lapse photography can be used to monitor snow glide rates simultaneously in several start zones and potentially provide insight into when, or if, a glide-snow avalanche will release. We have also used time-lapse photography to better understand processes involved in wet-snow avalanche release, by correlating avalanche occurrences with local meteorological data. Results show that onset of wet-snow avalanching typically occurs during the first period of prolonged above freezing temperatures. Furthermore, there typically is a lag of a few hours between the rise in snow surface temperature and the onset of avalanching. Overall, our results show that time-lapse photography can be used to improve our understanding of processes involved in avalanche formation, and ultimately, improve their forecasting.
Language of Article: English
Presenters: Unknown
Keywords: time-lapse photography, image processing, avalanche activity, glide-snow avalanche
Page Number(s): 950-954
Subjects: glide avalanche time lapse photography avalanche activity
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Digital Abstract Not Available
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