Item: How ground temperature affects temperature gradient metamorphism--an empirical study
Title: How ground temperature affects temperature gradient metamorphism--an empirical study
Proceedings: 1986 International Snow Science Workshop, Lake Tahoe, California, USA
Authors: Bruce Tremper
Abstract: The temperature at the snow/ground interface was sampled at 285 points in the common avalanche starting zones at Big Sky Ski Area, Montana in March of 1983. The temperatures, when plotted on a map, show a definite pattern of warm and cold areas ranging from +OAoC to -5.6°C. An examination of past snowpit and avalanche records show that: (1) Temperature gradient (TG) metamorphism occurs more rapidly and later comprises a greater percentage of the vertical profile of the snowpack on warm areas as opposed to cold areas. (2) In the early season (usually from October through December) full-depth avalanche cycles running on TG snow tend to begin first on warm areas. Also, once a path runs to the ground on a warm area, it tends to run to the ground again--often several times--throughout the season. (3) Early season ski and/or boot compaction of snow in avalanche starting zones before the snow metamorphoses to TG significantly reduces the number and extent of full-depth avalanches runing to the ground on TG snow.
Keywords: ground interface, starting zone, metamorphism, avalanche
Digital Abstract Not Available