Back Country Safety
Tuesday, September 8th, 2009
Jeremiah Logemann asked:
As a back country snowboarder I have mixed feelings when I hear of tragedy on the mountain. I do feel sorry for the victims because sometimes very experienced people get caught in freak situations. I also feel angry about the number of inexperienced people that venture off where they shouldn’t be without the proper training. I would like to work toward a safer sport by advocating back country safety programs like Friends of Berthood Pass, and CAIC, Colorado Avalanche Information Center. By getting people educated we can reduce fatalities on the mountains we love. Here I will discuss the three basic factors that contribute to avalanches. They are terrain, snowpack, and weather.
The first step in avalanche safety is to be able to recognize avalanche terrain. Most avalanches occur on slopes between 30 and 45 degrees, but can occur on slopes from 25 to 60 degrees depending on other variables. Another factor is the slope’s aspect. In other words the direction the slope faces. Is the face on the windward or leeward side, is the snow sun baked or in the shade. The last factor is the features of the slope. Are there trees or outcroppings that would break up an avalanche lane of travel? What is the shape of the slope?
The second factor in the cause of avalanches is the snow pack. Snow builds up on a mountain in layers with every weather event. To study the layers to determine the safety of the slope, cut a column of snow with a snow saw. The dense, dark, strong layers consist of small round snow grain that is well bonded. The “sugary” or loose layers that are lighter in color and are poorly bonded are the weaker layers. If the dense layer is on the bottom with the light sugar layer on top then have fun. If the sugar layer is below the dense layer it will not be able to support the dense layer. One track by a snowboarder may then cause the slope to slide.
The effect of weather on a slope is the third factor that causes avalanches. Snow that falls very quickly puts much more stress on a slope than it may be able to handle. Another less obvious variable is wind. Wind can redistribute large amounts of snow. Temperature can also play a large part in the cause of an avalanche. Warmer temperatures can produce a stronger snowpack, but if the temperature increases too quickly the snowpack will become too heavy for lower layers to support it.
The main ingredient in a back country snowboarding fatality is YOU. Snowboarders attempting back country recreation need to understand the above mentioned factors, but also be equipped with the right tools and know how to use them. Never enter the back country alone. Always ride with other experienced back country riders. Wear and understand how to use tracking beacons, probes, saws, shovels, and avilungs. Let’s all do our part to make the mountains a safer place. For more info about avalanches check out these sites: www.tetongravity.com/forums/ and www.fsavalanche.org/basics/weather
NESTOR
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As a back country snowboarder I have mixed feelings when I hear of tragedy on the mountain. I do feel sorry for the victims because sometimes very experienced people get caught in freak situations. I also feel angry about the number of inexperienced people that venture off where they shouldn’t be without the proper training. I would like to work toward a safer sport by advocating back country safety programs like Friends of Berthood Pass, and CAIC, Colorado Avalanche Information Center. By getting people educated we can reduce fatalities on the mountains we love. Here I will discuss the three basic factors that contribute to avalanches. They are terrain, snowpack, and weather.
The first step in avalanche safety is to be able to recognize avalanche terrain. Most avalanches occur on slopes between 30 and 45 degrees, but can occur on slopes from 25 to 60 degrees depending on other variables. Another factor is the slope’s aspect. In other words the direction the slope faces. Is the face on the windward or leeward side, is the snow sun baked or in the shade. The last factor is the features of the slope. Are there trees or outcroppings that would break up an avalanche lane of travel? What is the shape of the slope?
The second factor in the cause of avalanches is the snow pack. Snow builds up on a mountain in layers with every weather event. To study the layers to determine the safety of the slope, cut a column of snow with a snow saw. The dense, dark, strong layers consist of small round snow grain that is well bonded. The “sugary” or loose layers that are lighter in color and are poorly bonded are the weaker layers. If the dense layer is on the bottom with the light sugar layer on top then have fun. If the sugar layer is below the dense layer it will not be able to support the dense layer. One track by a snowboarder may then cause the slope to slide.
The effect of weather on a slope is the third factor that causes avalanches. Snow that falls very quickly puts much more stress on a slope than it may be able to handle. Another less obvious variable is wind. Wind can redistribute large amounts of snow. Temperature can also play a large part in the cause of an avalanche. Warmer temperatures can produce a stronger snowpack, but if the temperature increases too quickly the snowpack will become too heavy for lower layers to support it.
The main ingredient in a back country snowboarding fatality is YOU. Snowboarders attempting back country recreation need to understand the above mentioned factors, but also be equipped with the right tools and know how to use them. Never enter the back country alone. Always ride with other experienced back country riders. Wear and understand how to use tracking beacons, probes, saws, shovels, and avilungs. Let’s all do our part to make the mountains a safer place. For more info about avalanches check out these sites: www.tetongravity.com/forums/ and www.fsavalanche.org/basics/weather
NESTOR
