Saturday, October 20, 2012

The Alta Avalanche Studies

To help stimulate your enthusiasm as ski season approaches, take a few moments to follow the footsteps of Alta's avalanche pioneers by reading The Avalanche Studies (available here as a 63 Mb pdf), which was written by Monty Atwater and Felix Koziol in 1949.  You won't be disappointed.

It summarizes the incredible early avalanche history of Alta, including the activities during the late 1930s and 1940s to tame the white death.  Here are some of the historical gold nuggets.

An early avalanche map of Alta, including current
and proposed facilities
Annotated avalanches photos that include some great
historical shots of early Alta ski area
Evidence that Mother Nature had as little sympathy for
cars then as she does today
Beautiful weather and avalanche charts that
became the template for what is done today
Discussions of avalanche control techniques
And then there is the text itself.  Many people believe that the snow at Alta is unusually dry, but this is simply not the case.  There are a number of reasons why the skiing is so good in the Wasatch, but it has more to do with the abundance of snow and the characteristics of winter storms than unusual dryness (see this article).  This fact was abundantly clear to Atwater and Koziol who wrote:
"Alta's typical snowfall is dry; that is, there is not enough free moisture in the snow crystals so that they will adhere when squeezed in the glove. It is varied in type: flake, granular, and pellet in all sizes and combinations. Its weight averages .092 of an inch of water per inch of snow, which is heavy for a "dry" type of snow [my emphasis]. These characteristics promote rapid settling and cohesion, those qualities of flotation without stiffness, and packing without becoming icy, which delight the heart of the skier."
The .092 inches of water per inch of snow reflects a 9.2% water content.  This is somewhat higher than the 8.4% observed in recent years, although this could simply be an artifact of changes in measuring location and techniques.

So, peruse The Alta Avalnche Studies this weekend and take a walk through the avalanche history of Alta with Monty Atwater and Felix Koziol.

1 comment:

  1. The U of U J. Willard Marriott Library has a collection of documents U.S. Forest Service from the Alta Avalanche Study Center, dating from 1953-1971