Avalanches: Natural Phenomena and Human-Induced Hazards

August 9, 2023

Adarsh Ojha

An avalanche is an unstable mass of snow and ice that rapidly descends down a mountainside. While its occurrence is natural, human activities can also trigger it. Steep terrain, combined with factors like new snowfall and temperature shifts, contribute to these dangerous downhill movements that pose significant hazards to mountainous regions

Types Of Avalanche

Slab Avalanche

The Fracture in the snowpack propagates rapidly with speeds of 80 and 200 km/h this causes the weak layer to collapse and the snow slab to slide

Loose Snow Avalanche

Loose snow avalanches, occurring as wet or dry variations, mainly unfold on highly inclined rocky landscapes. These events typically follow the accumulation of fresh snow and a notable rise in temperature. The interplay of these factors contributes to unstable conditions where the snowpack loses cohesion and readily gives way. The resultant downhill movement can pose substantial dangers to both natural environments and human activities situated in these hazardous zones, warranting vigilant monitoring and precautionary measures.

Powder Snow Avalanche

An amalgamation of diverse types, encompassing loose snow and slab avalanches. The lower segment comprises a compacted stratum of snow, ice, and air particles. Overlying this layer is a billowy mass of powdered snow, which, as it descends the slope, has the potential to accumulate momentum and escalate into a more substantial and hazardous avalanche, posing heightened risks to the surrounding terrain and structures.

Glide Avalanche

A glide avalanche is the sliding of an entire Snowpack or a large portion of it, often on a lubricated layer of snow. These avalanches usually start at a high point on the slope and can travel considerable distances.

Cornice Avalanche

Cornice avalanches result from wind-formed overhanging snow edges on steep terrain. These cornices amalgamate horizontally due to wind deposition. Such formations are prevalent on mountain slopes, particularly on the sheltered side, where accumulated snow undergoes this unique process, occasionally leading to avalanche risks

Icefall Avalanche

Contains snowflakes of varying sizes from tiny chunks of ice to boulder-sized chunks of ice

Essential Avalanche Rescue Equipment

Avalanche Victim Detector

These are small compact radios that are used to identify avalanche-prone locations. These transmit electromagnetic signals picked up by another transceiver on the receive mode.

Avalanche Rod

Avalanche rods are used by avalanche rescuers to probe avalanche debris and search for victims buried beneath it.

Air Bag

It keeps the climber afloat if caught in an avalanche

Avalanche Cord

The red rope which is attached to the person’s belt, the string has a red color which gives the red color to the snow and is visible from a distance which makes it easy for the rescue team to locate the victim

Precautions That You Should Follow For Your Safety Before Moving Out In Snow Bound Areas

There should be no movement for 72 hours. if a foot or more of fresh snow has accumulated
Never walk alone in an avalanche-prone area, you should always walk with a team
If the team is roped to move forward, you must untie the rope before traversing an avalanche-prone slope
Avalanche-prone slopes must be crossed one by one
The route should be along the ridge line and avoid walking on cornices
If caught in an avalanche, cover your mouth with a balaclava, the snow will not enter your mouth.

What to do if caught in an avalanche?

Try to run out of the avalanche zone or in the direction of the avalanche flow
Take cocoon position
Cover your mouth and nose so you don’t suffocate yet

If Survivor

Do not panic
Mark last seen the point
Send for help
Quick search
Search surface below last seen point
Probing
First Aid
Evacuation