Near-surface faceted crystals and their effect on snow stability, Red Mountain Pass Corridor, Colorado

TitleNear-surface faceted crystals and their effect on snow stability, Red Mountain Pass Corridor, Colorado
Publication TypeConference Proceedings
Year of Conference1998
AuthorsStock, J., Elder K., and Birkeland K.
Conference Name66th Annual Western Snow Conference
Series TitleProceedings of the 66th Annual Western Snow Conference
Date PublishedApril 1998
PublisherWestern Snow Conference
Conference LocationSnowbird, Utah
KeywordsAvalanche forecasting, Snow crystals
Abstract

Avalanches may be important hydrologically if avalanche deposits alter the timing and volume of runoff. Avalanches often fail from a weak layer such as surface hoar. graupel. or faceted crystals. One important type of faceted crystal. called near-surface faceted crystals. form in the near-surface layers. During the 1997/98 winter. A study of near-surface faceted crystals was conducted along the Red Mountain Pass corridor, Colorado. Six types of near-surface faceted crystals were differentiated: small faceted crystals, radiation recrystallization grains. Faceted precipitation crystals, near-surface hoar, faceted partly-decomposed precipitation crystals and needles. A particularly well-developed near-surface facet layer that evolved in December acted as the dominant weak layer in the study area for seven weeks. Observation of 14 avalanches showed that 79% of the failures occurred on near-surface faceted layers. The majority of stability test failures occurred on near-surface faceted layers. Understanding the growth of near-surface faceted crystals and their effect on snow stability is important for avalanche forecasting.

URLsites/westernsnowconference.org/PDFs/1998Stock.pdf