Effects of Snowmobile Use on Snowpack
Chemistry in Yellowstone National Park, 1998
by George P. Ingersoll
Prepared in cooperation with the NATIONAL PARK SERVICE
Available from the U.S. Geological Survey, Branch of Information Services, Box 25286, Denver Federal Center, Denver, CO 80225, USGS Water-Resources Investigations Report 99–4148, 23 p., 8 figs.
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Abstract
Snowmobile use in Yellowstone National Park has increased substantially in the past three decades. In areas of greatest snowmobile use, elevated levels of by-products of gasoline combustion such as ammonium and benzene have been detected in snowpack samples. Annual snowpacks and snow-covered roadways trap deposition from local and regional atmospheric emissions.
Snowpack samples representing most of the winter precipitation were collected at about the time of maximum annual snow accumulation at a variety of locations in the park to observe effects of a range of snowmobile traffic levels. Concentrations of organic and inorganic compounds in snow samples from pairs of sites located directly in and off snow-packed roadways used by snowmobiles were compared to concentrations in samples collected at nearby off-road sites. Concentrations of ammonium were 2 to 5 times higher for the in-road snow compared to off-road snow for each pair of sites. Thus, concentrations decreased rapidly with distance from roadways. In addition, concentrations of ammonium, nitrate, sulfate, benzene, and toluene in snow were positively correlated with snowmobile use.
Table of Contents
Abstract
INTRODUCTION
Background
Purpose and Scope
Description of Study Area
Acknowledgments
SAMPLE-COLLECTION LOCATIONS AND METHODS
ANALYTICAL PROCEDURES
SNOWPACK CHEMISTRY
Major Ions
Selected Hydrocarbons
Snowmelt Runoff
PATTERNS OF CHEMISTRY RELATIVE TO SNOWMOBILE USE
CONCLUSIONS
REFERENCES
