Basic Avalanche Awareness:

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Basic Avalanche Awareness:

An introduction to snow safety in Svalbard

Holt Hancock

07/02/2017 Cryoslope Svalbard photo

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Introduction

• Avalanches occur throughout svalbard

• Unique avalanche conditions and problems associated with Svalbard’s climate and setting

• Recreationalists typically

cause avalanches that affect their group

– This is preventable!

Eckerstorfer and Christiansen image

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Introduction

If you don’t know, don’t go

Think terrain, not snow

Human factors

3 Axioms / Things to remember:

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If you don’t know, don’t go

• Types of avalanches in Svalbard

• Weather warning signs

• Snowpack warning signs

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What is an avalanche?

A mass of snow sliding, tumbling, or flowing down

an inclined surface

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What is an avalanche?

A mass of snow sliding, tumbling, or flowing down

an inclined surface

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Svalbard (Snow) Avalanches

4 Types

• Slab

• Cornice fall

• Slushflows (slush

avalanches)

• Loose snow

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Slab avalanches

– Cohesive layer of snow that slides on underlying layers

– Triggered by the victim or a

member of their

party _{SLF photo}

Most recreational avalanche accidents involve slab avalanches

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Slab avalanches

Slab: wind

drifted snow or new storm snow Weak layer:

facets (sugar snow)

Bed surface: ice layer or hard old snow

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Slab avalanches

Lia, 2010

Max Eckerstorfer photo

Crown (Slab)

Weak layer Bed surface

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Slab avalanches

Starting zone / release area

Track / Path

Runout /

deposition

zone / debris

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Slab avalanches

Cryoslope Svalbard photo

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Slab avalanches

Erik Næss photo

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Slab avalanches

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Cornice fall avalanches

First, what is a cornice?

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Cornice fall avalanches

Not always this obvious where the cornice starts!!

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Cornice fall avalanches

• Very common avalanche type in Svalbard

• Slab avalanche often releases due to impact of falling cornice

• Difficult to forecast

timing of cornice failure

• End of snow season

• Warm temperatures

• During storms?

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Cornice fall avalanches

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Slushflows

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Slushflows

• Slush avalanches

• Associated with heavy rain / snow melt

• Snowpack becomes saturated

• Occur in different terrain than other avalanches

Svalbardposten photo from January 30th, 2012

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Loose snow avalanches

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Avalanche Triangle

Terrain

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Is the weather contributing to increased avalanche danger?

Terrain

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Warning Signs: Weather

Recent heavy snowfall (>15 cms)

Erik Næss photo

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Warning Signs: Weather

Strong winds; especially in combination with loose snow

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Warning Signs: Weather

Rapid warming and rain

Cryoslope Svalbard photos

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Is the snowpack unstable ?

Terrain

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Warning Signs: Snowpack

Recent avalanche activity

Cryoslope Svalbard photos

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Warning Signs: Snowpack

Shooting cracks and ‘‘whumpfing’’

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If you don’t know, don’t go

• What can we do to know?

– Check the weather and avalanche forecast

• Varsom.no

– Look for signs of recent avalanche activity and unstable snow

– Ask!

• Think terrain, not snow

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Think terrain, not snow

If snow is the problem, terrain is the answer

Terrain

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What is avalanche terrain ?

Release areas

• Avalanches typically release on slopes between 30 and 45 degrees

• ‘‘steep slopes’’

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A brief note on slushflows:

• Release from lower angle

terrain (typically 5 – 30 degrees)

• Watch for water pooling in the snowpack

Erik Hestnes figure

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What is avalanche terrain?

Runout Zones

• During periods of elevated avalanche danger, valleys are not necessarily safe!

• It is possible to trigger avalanches from

below

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Terrain Traps

Especially dangerous avalanche terrain

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Think terrain, not snow

• Learn to identify slope angles

– Avoid steep slopes

• Be aware of your surroundings

– Runout zones

– Terrain traps

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Human factors

Terrain

What were they thinking?!

What was I thinking?!

People

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The human factor

Common human factors / errors

• Time constraints (weekend warrior)

• Familiarity

• Group dynamics

• Expert halo

• Blue sky syndrome

Most avalanches involving people are triggered by their own actions!

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The human factor

• Safe travel protocols

– Basic avalanche gear

– One at a time in avalanche terrain

• Communicate within your group – Speak up!!

• Have a plan…but be flexible!

How can we reduce our risks?

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Trip Planning

Consider:

• Is the weather contributing to increased avalanche danger?

• Is the snowpack unstable?

• Will I be traveling in avalanche terrain?

• How are human factors influencing my (our)

assessment of the avalanche hazard?

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Again, remember:

If you don’t know, don’t go

Think terrain, not snow

Human factors

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