Item: Unusual Dry Slab Avalanche Releases Involving Dust-on-Snow Layers in Colorado
-
-
Title: Unusual Dry Slab Avalanche Releases Involving Dust-on-Snow Layers in Colorado
Proceedings: International Snow Science Workshop 2016 Proceedings, Breckenridge, CO, USA
Authors:
- Zach M. Guy [ Crested Butte Avalanche Center, Crested Butte, CO, USA ]
- Jeffrey S. Deems [ National Snow and Ice Data Center, Boulder, CO, USA ]
Date: 2016-10-02
Abstract: In recent decades, dust-on-snow events are increasing in both frequency and geographic extent in the Western U.S. Although dust layers have gained a reputation for creating unusual avalanche conditions, especially with wet avalanches, there has been little research on the effects of dust layers on dry slab avalanche release. Landry (2014) presented several observational and theoretical processes on how dust layers can affect dry snow via faceting and crust formation. In this paper, we present several case studies of dry slab avalanche events that were unusual or challenging to predict during the past several seasons in Crested Butte, CO. We describe snowpack, weather, and avalanche observations leading to several near misses or surprising avalanches involving dust layers. For each case, we hypothesize on the effects of the dust layer and how it contributed to unusual or long-live instabilities. These events demonstrate several unique metamorphic and rapid change processes involving dust on snow, with the goal of improving avalanche forecasting. We hope these unusual and interesting avalanche occurrences will inspire further research in the field and laboratory setting and promote an increase in the documentation of dust observations and avalanche events involving dust layers.
Object ID: ISSW16_O3.03.pdf
Language of Article: English
Presenter(s):
Keywords: dust, slab avalanches, metamorphism, forecasting
Page Number(s): 74-81
Subjects: slab avalanches snow metamorphism forecasting
-