Item: METEOROLOGICAL AND SNOWPACK PROPERTIES ASSOCIATED WITH CRUST-ADJACENT PERSISTENT WEAK LAYERS - PART 1: A REVIEW OF PREVIOUS RESEARCH
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Title: METEOROLOGICAL AND SNOWPACK PROPERTIES ASSOCIATED WITH CRUST-ADJACENT PERSISTENT WEAK LAYERS - PART 1: A REVIEW OF PREVIOUS RESEARCH
Proceedings: International Snow Science Workshop 2024, Tromsø, Norway
Authors:
- Andy Moderow [ Chugach National Forest Avalanche Center ]
- Andrew Schauer [ Chugach National Forest Avalanche Center ]
- Aleph Johnston-Bloom [ David Hamre and Associates ]
Date: 2024-09-23
Abstract: Previous research has explored the mechanisms - in theory, field studies, and lab experiments - that explain the formation of faceted grains at crust/snowpack interfaces. Additionally, numerous case studies have described operational challenges that crust-adjacent persistent weak layers have presented to avalanche forecasting operations, accompanied by the meteorological and snowpack conditions that contributed to long-term avalanche issues. Recently, avalanche forecasting frameworks and decision support tools have been crafted to help operations identify indicators for when persistent weak layers may be activated, producing persistent slab or deep persistent slab avalanches. This paper reviews and connects theory, field studies, lab experiments, case studies, and forecasting tools to identify a set of meteorological and snowpack indicators that may be specifically associated with long-term, crust-adjacent, persistent weak layer instability. These indicators may assist avalanche forecasting operations as they sort through a myriad of data points in attempts to anticipate the longevity of crust-associated dry slab avalanche issues. A companion paper then tests select indicators against two groupings of substantial crusts in Turnagain Pass, Alaska, USA: (1) those with a weak layer that produced long-term avalanche problems, and (2) those with short-lived or no reactivity.
Object ID: ISSW2024_P1.10.pdf
Language of Article: English
Presenter(s): Andy Moderow
Keywords: crusts, melt-freeze layers, persistent weak layer, deep slab, avalanche forecasting
Page Number(s): 132 - 139
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