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Publications - Occasional Papers

Avalanche Atlas, Ouray County, Colorado

INSTAAR Occasional Paper 25

1977, 132 pp. 34 plates. (cost: $5)

[From the Preface] This is the second avalanche atlas produced by the Institute of Arctic and Alpine Research (INSTAAR) for the main transportation arteries of a San Juan Mountain county. In a sense, it is a natural extension of the first, compiled by Miller, Armstrong, and Armstrong (1976), for San Juan County. Together, the two atlases represent a major component of INSTAAR’s research, now in its sixth year, that deals with snow and avalanche studies in the San Juan Mountains. This atlas constitutes the work of the INSTAAR Snow and Avalanche Project, based at Silverton under the leadership of Richard L. Armstrong. It is complemented by a natural hazard research project supported by a grant from the National Aeronautical and Space Administration (NASA) Office of University Affairs.

Snow avalanches present a major obstacle to effective land-use planning in the San Juan Mountains in particular, and in the entire mountain area of the Western United States and Canada in general. Despite several generations of studies in Switzerland, and in adjacent alpine countries, many serious problems remain unsolved. It is perhaps not so remarkable that the mechanical properties of snow are so far from being fully understood when it is realized that the physical properties of the medium itself change constantly in time and space. In view of this problem, it seemed logical for INSTAAR to adopt a multi-facetted strategy which includes: studies of the properties of snow; attempts to develop a numerical forecast model to improve the prediction of avalanche occurrence; systematic collection of data on current and past avalanche events; studies of alternative methods to explosives for artificial avalanche release; and graphic portrayal of avalanche path characteristics in map and atlas forms.

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