Basic Avalanche Awareness: An introduction to snow safety in Svalbard

Holt Hancock 07/02/2017 Cryoslope Svalbard photo

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

Introduction

If you don’t know, don’t go

Think terrain, not snow

Human factors

3 Axioms / Things to remember:

If you don’t know, don’t go

• Types of avalanches in Svalbard

• Weather warning signs

• Snowpack warning signs

What is an avalanche?

A mass of snow sliding, tumbling, or flowing down an inclined surface

What is an avalanche?

A mass of snow sliding, tumbling, or flowing down an inclined surface

Svalbard (Snow) Avalanches

4 Types • Slab • Cornice fall • Slushflows

(slush avalanches)

• Loose snow

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

Slab avalanches

Slab: wind drifted snow or new storm snow

Weak layer: facets (sugar snow)

Bed surface: ice layer or hard old snow

Slab avalanches Lia, 2010 Max Eckerstorfer photo

Crown (Slab)

Weak layer

Bed surface

Slab avalanches

Starting zone / release area

Track / Path

Runout / deposition zone / debris

Slab avalanches

Cryoslope Svalbard photo

Slab avalanches Erik Næss photo

Slab avalanches

Cryoslope Svalbard photo

Cornice fall avalanches First, what is a cornice?

Cryoslope Svalbard photo

Cornice fall avalanches

Not always this obvious where the cornice starts!!

Cryoslope Svalbard photo

Cornice fall avalanches

Cryoslope Svalbard photo

• 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?

Cornice fall avalanches

Cryoslope Svalbard photo

Slushflows

Cryoslope Svalbard photo

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

Loose snow avalanches

Cryoslope Svalbard photo

Avalanche Triangle

Terrain

Is the weather contributing to increased avalanche danger?

Terrain

Warning Signs: Weather

Recent heavy snowfall (>15 cms) Erik Næss photo

Warning Signs: Weather

Strong winds; especially in combination with loose snow

Cryoslope Svalbard photo

Warning Signs: Weather

Rapid warming and rain

Cryoslope Svalbard photos

Is the snowpack unstable?

Terrain

Warning Signs: Snowpack Recent avalanche activity

Cryoslope Svalbard photos

Warning Signs: Snowpack Shooting cracks and ‘‘whumpfing’’

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

Think terrain, not snow If snow is the problem, terrain is the answer

Terrain

What is avalanche terrain? Release areas • Avalanches typically

release on slopes between 30 and 45 degrees

• ‘‘steep slopes’’

Cryoslope Svalbard photo

A brief note on slushflows:

• Release from lower angle terrain (typically 5 – 30 degrees)

• Watch for water pooling in the snowpack

Erik Hestnes figure

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

Cryoslope Svalbard photo

Terrain Traps Especially dangerous avalanche terrain

Think terrain, not snow

• Learn to identify slope angles – Avoid steep slopes

• Be aware of your surroundings – Runout zones – Terrain traps

Human factors

Terrain

What were they thinking?!

What was I thinking?!

People

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!

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?

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?

Again, remember:

If you don’t know, don’t go

Think terrain, not snow

Human factors

Questions?

Have a fun (and safe) winter and spring!