The ability to participate in a wide variety of winter sports is one of the best perks of living in Colorado. With winter sports, however, come dangers, especially in the backcountry. One danger common in backcountry mountain terrain is avalanches. According to the Colorado Avalanche Information Center (CAIC), Since October 2010, 10 people have been killed in the Colorado backcountry by avalanches, with many more needing to be rescued. As the weather begins to warm up, avalanches will become more common. The following tips can help you avoid or survive this danger.
The first part of being prepared for an avalanche is knowing the danger signs:
- Avalanches only occur in terrain with more than a 30 degree slope (think the angle between the two and three on an analog clock). Most avalanches occur on slopes greater than 35 degrees.
- The snowpack must be unstable in order for an avalanche to occur. This generally happens when a hard, strong layer of snow is resting on a softer, weaker layer of snow.
- An avalanche will not occur without a trigger. This trigger could be weight from additional snow or weight from a person traveling on the snow.
- Avalanches are more likely to occur after a heavy snowfall as this increases snow instability.
- Wet avalanches are likely to occur in warmer temperatures. Melting snow brings additional moisture which weakens the bonds between snow layers.
- Recent avalanche activity in the same area is an indicator of snow instability and a sign that more avalanches are likely to occur.
- Wind can create dangerous snow slabs. If there has recently been high wind, an avalanche is more likely to occur.
- Cracks in the snow surface and/or “whoomping” sounds mean that a weak layer is collapsing and snowpack is unstable.
If you get caught by an avalanche (The following tips are from the Forest Service National Avalanche Center):
- Try to ski or board off the avalanche slab by maintaining momentum and angling to the edge of the slide.
- Discard poles (never ski in the backcountry with your pole straps on).
- If you have releasable bindings and your skis or board come off, roll on to your back with your feet downhill. Swim hard up stream to try to get to the rear of the avalanche.
- Dig into the surface to slow yourself down and let as much debris as possible go past.
- Grab a tree if you can
- As the avalanche slows, try to thrust your hand or some part of your body above the surface and then stick a hand in front of your face to make an air space around your mouth.
- If completely buried, try to remain calm -hopefully your partners have practiced rescue techniques and they will quickly find you.
The best way to survive an avalanche is to avoid conditions likely to result in one. If you do get caught in an avalanche the tips above may save your life.