Articles | Volume 12, issue 3
The Cryosphere, 12, 1121–1135, 2018
The Cryosphere, 12, 1121–1135, 2018

Research article 28 Mar 2018

Research article | 28 Mar 2018

Snowmobile impacts on snowpack physical and mechanical properties

Steven R. Fassnacht1,2,3,4, Jared T. Heath1,5, Niah B. H. Venable1,3, and Kelly J. Elder6 Steven R. Fassnacht et al.
  • 1Department of Ecosystem Science and Sustainability – Watershed Science, Colorado State University, Fort Collins, 80523-1476 CO, USA
  • 2Cooperative Institute for Research in the Atmosphere, Fort Collins, 80523-1375 CO, USA
  • 3Natural Resources Ecology Laboratory, Fort Collins, 80523-1499 CO, USA
  • 4Geographisches Institut, Georg-August-Universität Göttingen, 37077 Göttingen, Germany
  • 5City of Fort Collins, Water Resources & Treatment, Fort Collins, 80521 CO, USA
  • 6Rocky Mountain Research Station, US Forest Service, Fort Collins, 80526 CO, USA

Abstract. Snowmobile use is a popular form of winter recreation in Colorado, particularly on public lands. To examine the effects of differing levels of use on snowpack properties, experiments were performed at two different areas, Rabbit Ears Pass near Steamboat Springs and at Fraser Experimental Forest near Fraser, Colorado USA. Differences between no use and varying degrees of snowmobile use (low, medium and high) on shallow (the operational standard of 30 cm) and deeper snowpacks (120 cm) were quantified and statistically assessed using measurements of snow density, temperature, stratigraphy, hardness, and ram resistance from snow pit profiles. A simple model was explored that estimated snow density changes from snowmobile use based on experimental results. Snowpack property changes were more pronounced for thinner snow accumulations. When snowmobile use started in deeper snow conditions, there was less difference in density, hardness, and ram resistance compared to the control case of no snowmobile use. These results have implications for the management of snowmobile use in times and places of shallower snow conditions where underlying natural resources could be affected by denser and harder snowpacks.

Short summary
We conducted a series of experiments to determine how snowpack properties change with varying snowmobile traffic. Experiments were initiated at a shallow (30 cm) and deep (120 cm) snow depth at two locations. Except for initiation at 120 cm, snowmobiles significantly changed the density, hardness, ram resistance, and basal layer crystal size. Temperature was not changed. A density change model was developed and tested. The results inform management of lands with snowmobile traffic.