The Geography of Glaciers and Perennial Snowfields in the American West

Authors

Andrew G. Fountain, Portland State UniversityFollow
Bryce Glenn, Portland State UniversityFollow
Hassan J. Basagic, Portland State UniversityFollow

Sponsor

This work was funded by the U.S. Geological Survey Western Mountain Initiative and the U.S. Forest Service.

Published In

Arctic, Antarctic, and Alpine Research

Document Type

Article

Publication Date

8-2017

Subjects

Glaciers -- Inventories -- West (U.S.), Glaciers -- West (U.S.) -- Measurement, Glaciers -- Climatic factors

Abstract

A comprehensive mid-20th century inventory of glaciers and perennial snowfields (G&PS) was compiled for the American West, west of the 100° meridian. The inventory was derived from U.S. Geological Survey 1:24,000 topographic maps based on aerial photographs acquired during 35 years, 1955–1990, of which the first 20 years or more was a cool period with little glacier change. The mapped features were filtered for those greater than 0.01 km². Results show that 5036 G&PS (672 km², 14 km³) populate eight states, of which about 1276 (554 km^2, 12 km³) are glaciers. Uncertainty is estimated at ±9% for area and ±20% for volume. Two populations of G&PS were identified based on air temperature and precipitation. The larger is found in a maritime climate of the Pacific Northwest, characterized by warm winter air temperatures and high winter precipitation (~2100 mm). The other population is continental in climate, characterized by cold winter air temperatures, relatively low winter precipitation (~880 mm), and located at higher elevations elsewhere. The G&PS in the Pacific Northwest, especially in the Olympic Mountains, are particularly vulnerable to warming winter air temperatures that will change the phase of winter precipitation from snow to rain, further accelerating glacier shrinkage in the future. Comparison with a recent inventory suggests that the total G&PS area in the American West may have decreased by as much as 39% since the mid-20th century.

Rights

Open Access – This work is licensed under a Creative Commons Attribution 4.0 (CC BY 4.0) International license.

Description

Originally appeared in Arctic, Antarctic, and Alpine Research, published by the Regents of the University of Colorado ©2017 and can be found online at: http://dx.doi.org/10.1657/AAAR0017-003

Data supporting this article can be found at: https://doi.org/10.15760/geology-data.04

DOI

10.1657/AAAR0017-003

Persistent Identifier

http://archives.pdx.edu/ds/psu/21113

Citation Details

Fountain, A. G., Glenn, B., & Basagic IV, H. J. (2017). The geography of glaciers and perennial snowfields in the American West. Arctic, Antarctic, and Alpine Research, 49(3), 391-410.