Avalanche: A Perilous Force of Nature

Introduction

Avalanches are a devastating natural phenomenon that can cause significant loss of life and property damage. Recognizing the staggering statistics and understanding the mechanics of avalanches help us mitigate their risks and prepare for their potential occurrence.

Statistics of Avalanche Fatalities

• The National Snow and Ice Data Center (NSIDC) reports an average of 28 avalanche-related fatalities per year in the United States from 2010 to 2020.
• Switzerland has the highest rate of avalanche fatalities in the world, with an average of 20 deaths annually over the past 20 years.
• Worldwide, an estimated 150-200 people die in avalanches each year.

How Avalanches Occur

Avalanches occur when a large mass of snow breaks loose from a mountain slope and slides rapidly downhill. The following factors contribute to avalanche formation:

• Snowpack: Unstable snow layers, such as weak layers buried deep within the snowpack, can provide a "shear" surface for avalanches to initiate.
• Slope Angle: Slopes with an angle of 25-45-degrees are most susceptible to avalanches, providing a balance of steepness and surface area for snow accumulation.
• Weather: Heavy snowfall, rain, or warm temperatures can increase the weight of the snowpack, triggering avalanches.

Types of Avalanches

• Loose-Snow Avalanches: These are the most common type, occurring when loose, dry snow on the slope surface breaks loose.
• Slab Avalanches: A cohesive layer of snow called a "slab" slides along a weaker layer beneath, creating a massive, high-speed avalanche.
• Wet Snow Avalanches: These occur when warm temperatures or rain saturate the snowpack, creating a heavy, slow-moving avalanche.

Avalanche Risk Management

Avalanche risk management includes several strategies aimed at reducing the likelihood and severity of avalanches:

• Avalanche Forecasting: Weather forecasts, snowpack assessments, and slope instability modeling help predict avalanche danger and inform decisions on travel and outdoor activities.
• Zoning and Restrictions: Restricting certain areas from development or regulating travel based on avalanche risk can reduce exposure to hazards.
• Slope Stabilization: Engineering techniques, such as slopes regrading and snow fences, can stabilize unstable slopes and prevent avalanches from forming.

Personal Safety in Avalanche Country

If you are traveling in avalanche country, follow these steps:

1. Educate Yourself: Learn to recognize avalanche terrain and receive avalanche safety training.
2. Get a Beacon and Probe: Carry an avalanche transceiver, shovel, and probe for self-rescue in case of an avalanche.
3. Check Conditions: Consult avalanche forecasts and avoid areas with high avalanche danger.
4. Travel with a Buddy: Never travel alone in avalanche country.
5. Be Aware of Your surroundings: Pay attention to slope angle, snowpack conditions, and weather changes.

Steps in Case of an Avalanche

If you are caught in an avalanche:

1. Try to Escape: Move sideways to avoid being buried.
2. Deploy Airbag: If you have an avalanche airbag backpack, deploy it immediately.
3. Protect Your Airspace: Create an air pocket in front of your face by inhaling deeply and keeping your mouth and nose exposed.
4. Swim: Try to swim to the surface if possible.
5. Wait for Rescue: If you are buried, conserve your energy and wait for rescue teams.

Call to Action

Avalanches are a serious threat that requires preparation and understanding. By educating ourselves, respecting avalanche warnings, and adopting safe practices, we can minimize the risks associated with this natural hazard and protect ourselves and others.