Avalanche Accidents in Canada. II. A Selection of Case Histories of Accidents 1943 to 1978

Publisher’s version / Version de l'éditeur:

Vous avez des questions? Nous pouvons vous aider. Pour communiquer directement avec un auteur, consultez la première page de la revue dans laquelle son article a été publié afin de trouver ses coordonnées. Si vous n’arrivez pas à les repérer, communiquez avec nous à PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca.

Questions? Contact the NRC Publications Archive team at

PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. If you wish to email the authors directly, please see the first page of the publication for their contact information.

https://publications-cnrc.canada.ca/fra/droits

L’accès à ce site Web et l’utilisation de son contenu sont assujettis aux conditions présentées dans le site LISEZ CES CONDITIONS ATTENTIVEMENT AVANT D’UTILISER CE SITE WEB.

Paper (National Research Council of Canada. Division of Building Research);

Issue 926

READ THESE TERMS AND CONDITIONS CAREFULLY BEFORE USING THIS WEBSITE. https://nrc-publications.canada.ca/eng/copyright

NRC Publications Archive Record / Notice des Archives des publications du CNRC :

https://nrc-publications.canada.ca/eng/view/object/?id=e32e20d3-e213-4f63-b926-51e188c82b55 https://publications-cnrc.canada.ca/fra/voir/objet/?id=e32e20d3-e213-4f63-b926-51e188c82b55

NRC Publications Archive

Archives des publications du CNRC

This publication could be one of several versions: author’s original, accepted manuscript or the publisher’s version. / La version de cette publication peut être l’une des suivantes : la version prépublication de l’auteur, la version acceptée du manuscrit ou la version de l’éditeur.

Access and use of this website and the material on it are subject to the Terms and Conditions set forth at

Avalanche Accidents in Canada. II. A Selection of Case Histories of

Accidents 1943 to 1978

ANALYZED

. . ' r . . - -. . - -. .

NATIONAL RESEARCH COUNCIL OF CANADA DIVISION OF BUILDING RESEARCH

AVALANCHE ACCIDENTS IN CANADA 11. A SELECTION OF CASE HISTORIES

OF ACCIDENTS 1943 TO 1978 b

Y

C.J. Stethem and P.A. Schaerer

DBR Paper No. 926 of the

Division of Building Research

AVALANCHE ACCIDENTS IN CANADA

11. A SELECTION OF CASE HISTORIES

OF

ABSTRACT

Case histories are presented of avalanche accidents in Canada that resulted in death or injury. A first volume describing accidents between 1955 and 1976 was published earlier (NRCC 17292). The present publication contains cases from the winters 1976 to 1978 and a few selected ones from earlier years. They contain a description of the weather, snow conditions, circumstances leading to the accident, the event, and the rescue operation.

ACCIDENTS C A U S ~ S PAR LES AVALANCHES AU CANADA

11. CHOIX DE CAS DOCUMENT~S D'ACCIDENTS DE 1943 1978 par C.J. Stethem and P.A. Schaerer

Des cas dlaccidents caus6s par des avalanches au Canada ayant provoqug la mort ou des blessures sont pr6sentGs. Un premier volume dgcrit les accidents qui se sont produits entre 1955 et 1976 a 6t6 publigs plus t6t

(NRCC 17292). Cette publication contient les cas des hivers de 1976 5 1978 et certains autres cas choisis dans le rgpgrtoire des ann6es pr6cGdentes. Les cas documenti% contiennent une description de la tempgrature, des conditions de la neige, des circonstances qui ont conduit 2 l'accident, l'accident comme tel, et 110p6ration de sauvetage.

FOREWORD

The objective of the avalanche research program of the Division of

Building Resea~ch

of the National Research Council is to develop and make

available information about snow avalanches and protection from them.

In partial fulfillment of this objective, case histories of accidents were

collected that either resulted in death, injury, or property damage or have

educational value.

first volume describing 40 accidents between 1955 and

1976 was published earlier (NRCC 17292).

The present publication contains

the accident cases of the two winters between 1976 and 1978 and some

additional ones from earlier years.

The case histories presented in this report were collected by

Mr. Chris Stethem, working on Contract OSS77-08171 with the National

Research Council of Canada. Mr. Stethem obtained the information from

published reports, from files of agencies and through interviews with

persons who were either eyewitnesses to the accident or involved in the

rescue operation.

The reader will notice an increase in the amount of information

concerning individual accidents towards the end of this report. The most

recent cases are well documented with weather, snowpack and avalanche

observations. This is a reflection of a growth in interest and knowledge of

personnel working in avalanche areas, which in some part, is the result of

education in which the National Research Council played an important role by

developing avalanche course programs, assisting in instruction and through

publications such as this one.

The compilation of accident case histories will continue, and

publication of

a

further volume containing the numerous accidents and

destructive avalanches of February 1979 is anticipated. Furthermore it is

planned to collect statistics about the numerous encounters that have not

resulted in death, injury, or serious property damage. The assistance of

individuals and agencies who make available information is gratefully

acknowledged, and it is expected that the same co-operation will continue.

Ottawa

July 1980

C.B. Crawford

Director, DBR/NRC

ACKNOWLEDGEMENT

The National Research Council wishes to express its thanks to the following

agencies, organizations, and individuals who have contributed information.

Apex Alpine Recreations Ltd.

Atmospheric Environment Service Canada

British Columbia Ministry of Transportation and Highways

British Columbia Ministry

Lands, Parks and Housing

British Columbia Ministry of the Attorney-General

Canadian Mountain Holidays

Canadian National Railways

Garibaldi Lifts Limited

Ocean Falls Corporation

Parks Canada

Suret6 de Quebec

Workers Compensation Board of British Columbia

B. Geisler

W.

Jenkins

W. Kleinschrot

R. Neville

C. Sadleir

LIST

OF THE ACCIDENTS

11 February

23 February

14 January

27 March

23 February

24 March

7 April

19 July

21 January

13 January

11 August

14 March

13 February

11 June

11 December

12 December

28 December

15 February

16 March

17 March

19 March

21 March

March

30 March

7 September

October

March

Kwinitsa

Workmen killed,

Construction camp destroyed

Fraser Canyon

Person on road killed

Fraser Canyon

Workman killed

Seymour Inlet

Workman killed

Woodbury Creek

Person on road killed

McGillivray Pass

Skiers killed

Torbit Mine

Workman killed

Mt. Garibaldi

Mountain climber killed

Silver Star

Skier killed

Ocean Falls

Persons in buildings killed,

buildings destroyed

Mt. St. Elias

Mountain climbers killed

Nine Mile Mountain

Snowmobile operator killed

Westcastle

Workman injured

Mt. Fisher

Mountain climbers injured

Sunshine Village

Skier buried

Chancellor Peak

Tadoussac

Parker Ridge

Diana Lake

Bugaboo

Bow Peak

Apex Mountain

Quartz Ridge

Lake Louise

Mt. Athabasca

President's Col

Whistler Mountain

Mountain climbers killed

Snowmobile operator killed

Skier killed

Skier killed

Skiers killed

Mountain climber killed

Skier killed

Skier killed

Skier killed

Mountain climbers injured

Mountain climber killed

Skiers buried

PREFACE

The list of accidents described in this publication is a reflection of

the change in activities in the mountains of Western Canada and the shift in

the type of involvements with avalanches. In the years before 1960

avalanche accidents occurred mainly on roads and in work areas such as

construction, mining and logging, but when recreation in the mountains

became more popular the number of acctdents involving skiers and mountain

climbers increased.

the average seven people per year have died in

avalanches in Canada between 1970 and 1978, the period when accurate records

were maintained. With 13 deaths the winter of 1976-1977 was above average,

and all 13 persons were involved in recreational activities.

Three important conclusions can be drawn from features common to several

cases.

1.

The time for survival of persons completely encased in the snow is very

short. This means that live rescue depends on the quick action of the

accident witnesses who must immediately search likely areas of burial.

Obviously rescue transceivers and probes assist greatly in locating buried

victims, and shovels carried by the rescuers are essential for a quick

recovery.

2.

Several persons on roads and on skis have died when a second avalanche

ran after the first one. For this reason danger from later avalanches and

proper safety measures must be considered in rescue and snow removal

operations.

3 .

_{Some skiers were caught in avalanches on slopes that had been treated}

with artillery fire a short time before. When a deep slab instability

exists such slopes may be considered safe only when avalanches were actually

observed and the unstable snow removed.

KWINITSA, SKEENA RIVER VALLEY, B.C. 11 FEBRUARY 1943 Three men k i l l e d , e l e v e n i n j u r e d , s e v e r a l b u i l d i n g s d e s t r o y e d WEATHER O b s e r v a t i o n s a t T e r r a c e A i r p o r t , 60 m ASL Temperature P r e c i p i t a t i o n O c

Date Max Min mm

7 February 4.5 3.0 45

8 February 3.5 0.5 3 0

9 February 4.0 -0.5 5 . 5

10 February 0 . 5 -6.5

11 February 0 -3.5 2.5

Experience h a s shown t h a t warm m o i s t u r e laden f r o n t s u s u a l l y a r r i v e e a r l i e r and d e p o s i t more snow a t t h e a c c i d e n t s i t e t h a n a t T e r r a c e .

On 12 and 13 February a t o t a l o f 51 mm o f p r e c i p i t a t i o n was r e c o r d e d a t T e r r a c e A i r p o r t .

SITUATION

The a c c i d e n t s i t e was a t McLean P o i n t on t h e s h o r e o f t h e Skeena River 85 km west o f T e r r a c e . A c o n s t r u c t i o n camp t o house workmen b u i l d i n g t h e highway from T e r r a c e t o P r i n c e Rupert was l o c a t e d b e s i d e t h e r a i l w a y t r a c k s i n t h e runout zone of a l a r g e avalanche g u l l y .

In t h e e a r l y w i n t e r o f 1942-43 o f f i c i a l s o f t h e Canadian National Railway v i s i t e d t h e camp and warned t h e s u p e r i n t e n d e n t o f t h e avalanche danger. In J a n u a r y 1943 an avalanche descended t h e g u l l y and blocked about 30 m of t h e r a i l w a y t r a c k b u t d i d n o t r e a c h t h e camp. A r a i l r o a d e n g i n e e r a g a i n v i s i t e d t h e camp and t o l d of a snowshed t h a t had been d e s t r o y e d a t t h e same s i t e about 10 y e a r s e a r l i e r .

By e a r l y February t h e avalanche h a z a r d had become t h e c e n t r a l t o p i c of d i s c u s s i o n among t h e 200 men working i n t h e camp. During t h e second week o f February a storm raged i n t h e a r e a . Most o f t h e p r e c i p i t a t i o n f e l l a s

r a i n a t t h e lower e l e v a t i o n s , b u t on t h e n i g h t o f 10 February snow was d e p o s i t e d a t t h e camp.

ACCIDENT SUMMARY

A t about 0730 h on 11 February most o f t h e men had f i n i s h e d break- f a s t and were p r e p a r i n g t o l e a v e f o r work, when suddenly a rumbling was h e a r d . An avalanche swept down t h e g u l l y and s t r u c k t h e camp c a r r y i n g away two small bunkhouses and t h e f i r s t a i d shack. S e v e r a l men were c a u g h t . One o f them who had been s t a n d i n g by a 14-ton locomotive was crushed by t h e moving snow and d e b r i s , and a n o t h e r one c l o s e - b y was swept away and b u r i e d . Those who escaped t h e avalanche a i d e d t h e i n j u r e d , moving them t o t h e remaining bunkhouses and t h e n , because o t h e r avalanches seemed imminent, t o t h e p a t r o l m e n ' s shack a t Telegraph P o i n t , 2 km west. Other s u r v i v o r s remained behind and s e a r c h e d f o r t h o s e s t i l l m i s s i n g .

A s t h e i n j u r e d men were b e i n g moved a second s l i d e s t r u c k , and d e s t r o y e d t h e two remaining bunkhouses. S e v e r a l men were p a r t i a l l y b u r i e d and some were c a r r i e d i n t o t h e r i v e r . Only t h e o f f i c e a t t h e e a s t end of t h e camp and t h e commissary a t t h e west end remained s t a n d i n g . About twenty minutes l a t e r , when t h e remaining men were moving t o s a f e t y , a t h i r d avalanche s t r u c k d e s t r o y i n g t h e o f f i c e . RESCUE

A westbound p a s s e n g e r t r a i n a r r i v e d a t t h e s i t e about one and one h a l f h o u r s a f t e r t h e f i r s t avalanche. Two d o c t o r s on board c r o s s e d t h e avalanche d e p o s i t t o a i d t h e i n j u r e d .

Two men remained m i s s i n g and s e v e r a l were i n c a p a c i t a t e d w i t h

i n j u r i e s . Word reached P r i n c e Rupert by t e l e g r a p h and a h o s p i t a l t r a i n was d i s p a t c h e d t o t h e s i t e t h e f o l l o w i n g morning. During t h e r e t u r n t r i p one man d i e d o f i n j u r i e s ; e l e v e n were h o s p i t a l i z e d .

On 15 February t h e body o f one o f t h e m i s s i n g men was l o c a t e d , b u t t h e o t h e r one was n e v e r found. Presumably i t was c a r r i e d away by t h e r i v e r . A few days l a t e r t h e camp was r e b u i l t i n a s a f e p o s i t i o n a t Telegraph P o i n t .

AVALANCHE

The McLean P o i n t avalanche f e l l some 1000 m v e r t i c a l l y o n t o t h e r a i l w a y and highway. The s t a r t i n g zone o f s o u t h e r l y a s p e c t was i n a s t e e p , wide g r a n i t e g u l l y covered w i t h mixed s p a r s e v e g e t a t i o n . The avalanche t r a c k was a s t e e p s i d e d g u l l y w i t h an average g r a d i e n t of 34O. Approximately 100 m above t h e r a i l w a y and t h e highway t h e g u l l y opened i n t o an a l l u v i a l f a n covered w i t h s h r u b s .

COMMENT

The Skeena R i v e r V a l l e y between T e r r a c e and P r i n c e Rupert i s one o f t h e most a c t i v e a v a l a n c h e a r e a s i n B r i t i s h Columbia where a v a l a n c h e s f r e q u e n t l y b l o c k t h e r a i l w a y and t h e highway. C o n s i d e r i n g t h e f r e q u e n t a v a l a n c h e s and t h e heavy a n n u a l s n o w f a l l i n t h e a r e a it s h o u l d b e

o b v i o u s even t o a layman t h a t t h e s t e e p g u l l y a t McLean P o i n t would b e an a v a l a n c h e t r a c k . I t i s h a r d t o b e l i e v e t h a t a c o n s t r u c t i o n camp was b u i l t t h e r e and m a i n t a i n e d d u r i n g t h e w i n t e r . The r e a s o n was p r o b a b l y t h a t o v e r a d i s t a n c e o f s e v e r a l k i l o m e t e r s t h e r e i s l i t t l e s p a c e between t h e s t e e p mountain and t h e r i v e r , t h e r e f o r e t h e a l l u v i a l f a n a t t h e t o e o f McLean Mountain was p a r t i c u l a r l y a t t r a c t i v e .

The r a i l w a y s t a f f was aware o f t h e a v a l a n c h e h a z a r d , because a snow shed had once c o v e r e d t h e t r a c k s a t t h i s s i t e and was d e s t r o y e d

18 A p r i l 1933. U n f o r t u n a t e l y t h e managers o f t h e highway c o n s t r u c t i o n company d i d n o t heed t h e warnings. T h e i r e x c u s e was t h a t t h e y had planned t o complete t h e j o b b e f o r e t h e w i n t e r , b u t o b v i o u s l y t h e y gambled h e a v i l y and l o s t when i t was n o t .

T h i s c a s e p r o v e s t h a t s e v e r a l d e s t r u c t i v e a v a l a n c h e s may r u n i n t h e same p a t h d u r i n g t h e same s t o r m and o f t e n w i t h i n a s h o r t t i m e o f e a c h o t h e r . For t h i s r e a s o n t h e d a n g e r from f u r t h e r a v a l a n c h e s must be a p r i m a r y concern f o r t h e l e a d e r o f any a v a l a n c h e r e s c u e m i s s i o n .

F i g u r e 1 View o f t h e a v a l a n c h e s i t e i n 1976 showing t h e r a i l w a y and t h e highway a t t h e s i d e of t h e r i v e r . (Photo c o u r t e s y B r i t i s h Columbia M i n i s t r y o f T r a n s p o r t a t i o n and Highways).

FRASER CANYON, B.C.

!

2 3 _{FEBRUARY 1949}

A t r u c k convoy l e f t Boston Bar l a t e on t h e a f t e r n o o n o f

2 3 February i n an a t t e m p t t o n e g o t i a t e t h e snowbound F r a s e r Canyon highway s o u t h towards Vancouver. S h o r t l y b e f o r e 1900 h t h e convoy was stopped a t t h e Hoodoo c u r v e by a s m a l l avalanche t h a t had been

p a r t i a l l y c l e a r e d by b u l l d o z e r . The d r i v e r o f a t r u c k t h a t had become s t u c k i n t h e d e p o s i t e d snow had begun t o mount t i r e c h a i n s when a l a r g e r avalanche s t r u c k . When it stopped o n l y t h e r o o f l i n e o f t h e t r u c k remained v i s i b l e and t h e d r i v e r had d i s a p p e a r e d i n t h e snow. The o t h e r d r i v e r s i n t h e convoy and t h e highway crew began a s e a r c h . Another avalanche s t r u c k and e n g u l f e d f i v e o f t h e r e s c u e r s sweeping them w e l l down t h e s l o p e towards t h e r i v e r . When t h e remaining

r e s c u e r s began a s e a r c h f o r t h e s e men a t h i r d avalanche s t r u c k b u r y i n g s e v e r a l men t o t h e i r k n e e s . M i r a c u l o u s l y a l l p e r s o n s were found a l i v e w i t h t h e e x c e p t i o n o f t h e f i r s t b u r i e d d r i v e r . H i s body was l o c a t e d a t t h e r e a r of h i s t r u c k t h e f o l l o w i n g day.

FRASER CANYON, B.C.

One r a i l w a y employee k i l l e d

14 JANUARY 1 95 0

Severe storms raged i n t h e F r a s e r Canyon e a r l y i n January 1950 causing t h r e e c l o s u r e s d u r i n g a three-week p e r i o d . A Canadian National Railway snow plow was working south o f Boston Bar on 14 January.

The crew parked t h e plow 1 3 km south o f Boston Bar and r e t u r n e d n o r t h with t h e engine t o p i c k up some o t h e r equipment b u t t h e foreman remained with t h e plow. While t h e crew was gone an avalanche c o n t a i n i n g both snow and rock s t r u c k t h e plow. I t was c a r r i e d p a r t way down t h e

embankment towards t h e r i v e r , and t h e foreman was swept i n t o t h e r i v e r . When t h e crew r e t u r n e d t h e foreman could n o t be found. The cause of t h e avalanche was a t t r i b u t e d t o r a i n which weakened t h e snow a t t h e canyon w a l l s .

SEYMOUR INLET 2 7 MARCH 1955

One logger k i l l e d , one i n j u r e d

LOCATION

I Seymour I n l e t i s on t h e P a c i f i c Coast o f B r i t i s h Columbia, 350 km

I northwest o f Vancouver and has a wet, maritime c l i m a t e . WEATHER

Moderate temperatures and r a i n p r e v a i l e d a t t h e a c c i d e n t s i t e on

2 7 March. Thaw p e r s i s t e d and t h e snowpack was w a t e r - s a t u r a t e d . ACCIDENT

A crew was yarding l o g s on a s t e e p s l o p e above Seymour I n l e t . On one t u r n o f t h e y a r d e r a stump r o l l e d over about 250 m upslope

from t h e e n g i n e ' s l o c a t i o n . During t h e n e x t t u r n a log which was being drawn caught t h e stump and d i s l o d g e d i t . The stump, t h e snow

surrounding i t , and some o f t h e s u r f a c e v e g e t a t i o n began t o move slowly down t h e s l o p e , then a f t e r f a l l i n g o n t o s t e e p e r t e r r a i n above t h e

y a r d e r r a p i d l y i n c r e a s e d i n volume and speed.

The signalman had c a l l e d o u t when t h e motion began. He himself was unable t o escape and was caught n e a r t h e t o p o f t h e avalanche, b u t a f t e r a r i d e of about 60 m was l e f t behind t h e moving snow. Two

workers i n t h e landing a r e a saw t h e s t a r t o f t h e avalanche and r a n c l e a r of i t . The y a r d e r e n g i n e e r n o t i c e d i t t o o l a t e , and t o g e t h e r with t h e donkey engine was engulfed i n t h e moving snow and d e b r i s and swept i n t o t h e i n l e t . When t h e avalanche stopped t h e only t h i n g s v i s i b l e were broken l o g s and o t h e r d e b r i s on t h e s u r f a c e o f t h e water.

1

A f t e r t h e avalanche had stopped t h e unscathed workers began a s u r f a c e s e a r c h and found t h e signalman n e a r t h e t o p o f t h e avalanche p a t h . He had s u s t a i n e d a broken arm and cracked r i b s . H i s companions c a r r i e d him on a s t r e t c h e r from t h e s l o p e . There was no s i g n o f t h e e n g i n e e r , a n d ' c o n t i n u i n g d e b r i s movement a t t h e edges o f t h e avalanche p a t h made a s e a r c h d i f f i c u l t . L a t e r s e a r c h e s on t h e same day r e v e a l e d no s i g n of t h e e n g i n e e r and t h e deep water i n t h e i n l e t made d i v i n g u n f e a s i b l e . The body was never found. The i n j u r e d signalman was flown by seaplane t o t h e h o s p i t a l a t A l e r t Bay.

AVALANCHE

The avalanche was triggered by the motion of the stump in the

water-saturated snowpack. The loose snow avalanche started on a slope

with an incline of about 10" at an elevation of about 600 m. For the

first 30 m it moved slowly with a width of about

m. After falling

over a transition onto an approximately 25" slope the avalanche quickly

gained momentum and volume, and expanded to a maximum width of 120 m.

The moving snow stripped the soil and vegetation down to the granite

bedrock.

COMMENT

The engineer would have had to run about 50 m to safety. Probably

he could have escaped if he had received a warning when the avalanche

started. Unfortunately due to the noise of the engine he could hear

neither a warning nor the avalanche until it was too late.

The avalanche carried the heavy logging equipment down the slope

and splintered logs with diameters greater than 1 m. This illustrates

the destructive force of the heavy, wet moving snow mixed with debris.

TAIL BLOCK

/

X P O S I T I O N OF SIGNALMAN PRIOR TO AVALANCHE

@ P O S I T I O N OF SIGNALMAN AFTER AVALANCHE

+

Figure

Sketch of the accident site at Seymour Inlet

WOODBURY CREEK, KASLO, B . C . 2 3 _{FEBRUARY 1957}

Person on road k i l l e d

LOCAT ION

The a c c i d e n t s i t e i s l o c a t e d about 18 km south of Kaslo on t h e s h o r e s of Kootenay Lake.

WEATHER

O b s e r v a t i o n s a t Kaslo c l i m a t e s t a t i o n 585 m ASL

Temperature O c

Date Max Min

P r e c i p i t a t i o n mm 2 0 February - 5 - 17 2 1 February - 6 . 5 -18 22 February

-

A storm raged from 22 t o 25 February d e p o s i t i n g deep snow i n t h e Nelson-Kaslo a r e a .

ACCIDENT SUMMARY

The Anglican m i n i s t e r from New Denver drove from Nelson t o Kaslo on S a t u r d a y a f t e r n o o n , 23 February. A s h o r t d i s t a n c e s o u t h of Woodbury Creek he was stopped by a small avalanche which had c r o s s e d t h e r o a d . He got o u t of h i s c a r and began t o shovel a p a t h through t h e snow. A second c a r stopped and t h e d r i v e r , a l o c a l r e s i d e n t , j o i n e d t h e m i n i s t e r a d v i s i n g him t o watch f o r f u r t h e r a v a l a n c h e s .

Suddenly a second, l a r g e r avalanche came from t h e b l u f f s above t h e r o a d . The second d r i v e r shouted a warning and r a n c l e a r o f t h e

a v a l a n c h e ' s p a t h , b u t t h e m i n i s t e r , running i n t h e o p p o s i t e d i r e c t i o n , was e n g u l f e d by t h e avalanche. A f t e r t h e snow had s e t t l e d t h e r e was no s i g n o f him.

RESCUE

The second d r i v e r looking over t h e d e p o s i t e d snow was unable t o l o c a t e t h e m i n i s t e r . He s e n t h i s w i f e , who had been w a i t i n g i n t h e i r c a r , f o r h e l p and continued t h e s e a r c h . About one hour a f t e r t h e

a c c i d e n t r e s c u e r s found t h e m i n i s t e r covered by 1 t o 2 m of snow, about 12 m below t h e road. No s i g n o f l i f e was e v i d e n t . .

AVALANCHE

The storm continued and a t h i r d avalanche r a n i n t h e same l o c a t i o n on t h e following day. The f a t a l avalanche was confined t o a narrow g u l l e y i n s t e e p , rocky b l u f f s above t h e road. The v e r t i c a l run of t h e avalanche was probably l e s s than 100 m, and a l e n g t h of about 2 5 m of road was covered by snow up t o 2 m deep.

COMMENT

A s i n o t h e r c a s e s t h e r e c u r r e n t n a t u r e o f an avalanche p a t h proved t o be t h e cause of t h e f a t a l i t y . The m i n i s t e r , who served both New Denver and Kaslo, f r e q u e n t l y t r a v e l l e d over t h e avalanche-prone road between t h e two towns was aware o f t h e danger. H i s p r e c a u t i o n s u s u a l l y included o b t a i n i n g advice from t h e Department o f Highways about t h e avalanche hazards b e f o r e he made t h e t r i p , b u t he n e g l e c t e d t o do s o on t h e day of t h e a c c i d e n t because he t r a v e l l e d over a n o t h e r road.

A t t h e time o f t h e a c c i d e n t t h e road was narrow, winding along t h e s h o r e s o f Kootenay Lake, and w i n t e r t r a v e l was hazardous. Since then t h e road has been r e l o c a t e d on a new, wider bench about 35 m above t h e l a k e . The r e c o n s t r u c t i o n seems t o have e l i m i n a t e d t h e avalanche problems a t t h i s s i t e .

McGILLIVRAY PASS, B.C. 24 MARCH 1959

Two skiers killed

McGillivray Pass is on the east side of the Pacific Coast Mountains between Anderson Lake and Bralorne, B.C. The summit, 1860 m high, is about 23 km SE of Bralorne.

WEATHER

During the week prior to 24 March 1959 approximately 45 cm of new snow accumulated in the McGillivray Pass area. March 24 was a clear, sunny day during which the temperature rose above 0°C and the top 15 cm of snow became heavy and moist.

ACCIDENT SUMMARY

I The accident itself was unobserved. At approximately 1300 h a

I young Bralorne couple met a friend while skiing towards McGillivray Pass. They intended to survey some land in the summit area, thinking of a

possible purchase. Their friend, considering the new snow and the high temperature, warned them of the avalanche hazard.

Later that afternoon the friend, while skiing at Telephone Ridge on the southwest side of the valley, noted a fresh avalanche deposit on the opposite side of the valley just southeast of the pass. Ski tracks led to the deposit but none left it. When he approached the avalanche for a closer look he realized that his friends had been caught in it.

I

The skier searched the deposition, digging and probing with ski poles at random but found nothing. He then skied back to his cabin some 3.5 km northwest of the site and telephoned to Bralorne for help.

The Royal Canadian Mounted Police in Bralorne received the report at 1745 h and gathered residents into a search party. They travelled a few miles by jeep, then by skis and snowshoes, arriving at the accident site several hours later. The rescuers searched throughout the night using scaling bars for probes and shovels for digging through the deposition. Avalanche guards had been posted to warn searchers of any further activity. On 25 March the search continued in temperatures below O"C with cloudy skies and light snowfall. At 1530 h on 25 March the first body was located; the second was located at 1035 h on

The

valley sides around McGillivray Pass contain numerous avalanche

paths. The accident site was about

km southeast of the summit and

100

above the valley floor on

a

slope with

SSW exposure, The

avalanche path was approximately

m wide,

m long and its snow was

deposited to a depth varying from 1.2 to

m. Deep new snowfall,

followed by high temperatures and radiant heat from the sun on the

southerly slope led to the unstable snow conditions.

COMMENT

The couple was evidently taking measurements of a plot of land when

caught by the avalanche. Both had skiis on and were holding the

opposite ends of a measuring tape. It would appear that they were so

occupied that they did not consider the danger from avalanches.

TORBIT MINE, ALICE ARM, B.C. 7 APRIL 1959 One miner k i l l e d WEATHER O b s e r v a t i o n s a t T o r b i t S i l v e r Mine, 300 m ASL Temperature P r e c i p i t a t i o n O C

Date Max Min mm

3 A p r i l 6.5 0 2 3

4 A p r i l 6 . 5 1 . O 9

5 A p r i l 6 . 0 0 1 . 5

6 A p r i l 7.0 -1.5 7 A p r i l 8 .O -0.5

In March a t o t a l s n o w f a l l o f 3.6 m accompanied by some r a i n was r e p o r t e d . On 7 A p r i l t h e t e m p e r a t u r e was above O°C and t h e snow was m e l t i n g .

ACCIDENT SUMMARY

The s u r f a c e r a i l w a y a t t h e T o r b i t S i l v e r Mine extended f o r about 800 m along t h e s i d e o f a s t e e p mountain between t h e mine and t h e m i l l . The e n t i r e l e n g t h o f t r a c k was covered by a snow shed.

On 7 A p r i l a t about 1300 h t h e t r a i n crew made t h e second t r i p o f t h e day from t h e m i l l t o t h e mine. The switchman rode t h e f i r s t of f i v e empty c a r s and t h e motorman t h e engine a t t h e r e a r . When t h e t r a i n approached t h e mine an avalanche s t r u c k , broke t h e shed around t h e f i r s t two c a r s and b u r i e d t h e switchman i n t h e d e b r i s .

RESCUE

A f t e r a t t e m p t i n g , without s u c c e s s , t o r e v e r s e t h e t r a i n t h e motorman and o t h e r h e l p e r s began t o c l e a r t h e d e b r i s around t h e l e a d c a r . A f t e r about twenty minutes t h e switchman was uncovered but showed no s i g n s of l i f e . Attempts t o r e v i v e t h e v i c t i m were u n s u c c e s s f u l .

AVALANCHE

The avalanche contained wet snow mixed with rock and appeared t o be t h e r e s u l t of high temperatures and snowmelt. I t r a n over a width o f about 30 m and deposited d e b r i s t o a maximum d e p t h o f 5 m i n t h e snow shed. About 1 2 _{m o f snow shed was d e s t r o y e d .}

COMMENT

A previous avalanche had occurred a t t h e same s i t e i n March 1959 and another one e i g h t y e a r s before t h a t . The weight o f t h e snowfall d e p o s i t e d on t h e shed appeared t o have been a problem, and t h e removal of t h i s snow

was

greater

avalanches. The snow was probably a l r e a d y s o heavy t h a t l i t t l e a d d i t i o n a l weight from t h e avalanche was r e q u i r e d t o break t h e shed.

REFERENCE

B r i t i s h Columbia Department of Mines and Petroleum Resources; Annual Report 1959; V i c t o r i a ,

B.C.

MT. GARIBALDI, SQUAMISH, B.C. 19

JULY

One climber killed, one injured

WEATHER

Temperatures ranged from 12 to 2S0c at Squamish during the week prior to 19 July. Precipitation of 3 mm was recorded on 16 July.

ACCIDENT

Three climbers left Vancouver 18 July intending to spend three days climbing in the Mt. Garibaldi area. When they arrived in

Garibaldi Park they were told by work crews that it had not been cold enough at night for the snow to consolidate properly. Because of this the group decided to climb in the early morning hours. At approximately 0500 h the party was caught in an avalanche about 250 m below the

Saddle Peak of Mt. Garibaldi. Two were injured, one severely, and the third was unhurt.

RESCUE

About one hour after the accident the unhurt climber left to summon help. At about 1100 h on the Diamond Head road he met a Provincial

Parks employee who drove him to the police station in Squamish.

The

At around 1600 h a second member of the party was noticed scrambling down the slopes below the accident site. He was picked up and flown to the Diamond Head Lodge. He was, however, unable to pinpoint the third person's location. The helicopter crew finally located the avalanche and the third member of the party but was unable to land there. A ground crew was organized and dropped about one hour's hike from the accident site. At 2240 h the rescue group, on foot, reached the victim who had died from severe chest injuries.

COMMENT

The climbers had essentially the right idea, to complete the climb early in the morning. Unfortunately they had not realized that the night temperature had not dropped low enough for the wet snow to stabilize, therefore that avalanche hazard can be high after a warm night.

SILVER STAR SKI AREA, VERNON, B.C. One s k i e r k i l l e d 21 JANUARY 1962 WEATHER O b s e r v a t i o n s a t Vernon BX c l i m a t e s t a t i o n , ' 5 1 6 m ASL Temperature P r e c i p i t a t i o n

.

Date Max Min mm

17 J a n u a r y -10 -15 N i 1 18 J a n u a r y - 15 -19.5 N i 1 19 J a n u a r y - 16 -19.5 , T r a c e 20 J a n u a r y -15 -25.5 N i 1 2 1 J a n u a r y -14 -25.5 N i 1 \,

i

Between 1 3 and 16 J a n u a r y 1 3 . 7 mm of p r e c i p i t a t i o n was r e c o r d e d a t Vernon BX s t a t i o n .

ACCIDENT

S h o r t l y b e f o r e noon on 21 J a n u a r y a l o c a l s k i r a c e r d e c i d e d t o s e t a d o w n h i l l c o u r s e on S i l v e r S t a r mountain. T o g e t h e r w i t h a younger companion h e g a t h e r e d a few s l a l o m p o l e s and s t a r t e d from t h e t o p of t h e p o m a l i f t . A s h o r t d i s t a n c e beyond t h e second g a t e t h e younger s k i e r f e l l , and h i s h a r n e s s e s r e l e a s e d . The o t h e r s k i e r c o n t i n u e d t o s e t t h e t h i r d g a t e w h i l e h i s companion remained b e h i n d t o f i x h i s s k i s . When t h e young s k i e r was m o b i l e a g a i n h e s k i e d t o t h e t h i r d g a t e b u t found no s i g n o f h i s f r i e n d , o n l y t h e g a t e p o l e s and a "break" i n t h e snow n e a r b y . T h i n k i n g n o t h i n g o f t h e "break1' ( f r a c t u r e ) h e c o n t i n u e d s k i i n g down assuming t h a t h i s f r i e n d had l e f t .

Another s k i e r r e s t i n g a t t h e c h a l e t n o t i c e d an a v a l a n c h e j u s t b e f o r e 1200 h b u t d i d n o t t h i n k t h a t anyone might b e t r a p p e d i n i t . A t 1310 h he ascended p a r t way up t h e p o m a l i f t t h e n t r a v e r s e d t h e s l o p e t o w a r d s t h e a v a l a n c h e l o o k i n g u p h i l l f o r f u r t h e r p o t e n t i a l a v a l a n c h e s . When he s k i e d t o a p o i n t below t h e a v a l a n c h e d e p o s i t i o n he n o t i c e d a

p a i r of s k i i s l y i n g on t h e s u r f a c e i n t h e midst o f t h e avalanche d e p o s i t i o n about 60 m above him.

RESCUE

The person who discovered t h e s k i s on t h e avalanche r e a l i z e d t h a t some one could be b u r i e d t h e r e . He s k i e d t o t h e bottom o f t h e h i l l , a l e r t e d t h e s k i p a t r o l , then mounted t h e l i f t and r e t u r n e d t o t h e s i t e . He f e l t it would be f a s t e r t o r i d e t h e l i f t than t o climb t h e 60 m

u p h i l l f o r an i n s p e c t i o n . A s k i i n s t r u c t o r , experienced i n avalanche r e s c u e and a l e r t e d by t h e s k i p a t r o l g a t h e r e d v o l u n t e e r s and some long s t i c k s f o r probing.

The f i r s t r e s c u e r t o a r r i v e on t h e s i t e discovered t h e v i c t i m ' s boots and one arm p r o t r u d i n g from t h e snow. Digging by hand proved u n s u c c e s s f u l , o n l y s h o v e l s could p e n e t r a t e t h e h a r d , chunky snow t o t h e v i c t i m ' s head approximately 75 cm below t h e s u r f a c e . The r e s c u e r s attempted a r t i f i c i a l r e s p i r a t i o n , b u t were u n s u c c e s s f u l i n t h e i r

a t t e m p t s t o r e v i v e t h e v i c t i m . A d o c t o r ordered t h e r e s c u e r s t o remove t h e v i c t i m by toboggan t o t h e s k i p a t r o l shack where he was pronounced dead due t o s u f f o c a t i o n .

AVALANCHE

The avalanche, which f r a c t u r e d j u s t below t h e t h i r d downhill g a t e , was t r i g g e r e d by t h e s k i e r . The s l a b f r a c t u r e occurred i n wind c r u s t e d snow and v a r i e d i n depth from 30 t o 75 cm. The s t a r t i n g zone, which had a g r a d i e n t v a r y i n g from 30' t o 3 S 0 , h e l d a SSE a s p e c t with ground s u r f a c e o f mixed s c r u b v e g e t a t i o n and broken s h a l e . The avalanche r a n a d i s t a n c e o f 220 m and was 15 m wide. I t d e p o s i t e d snow t o a maximum depth o f 1.2 m . The d e p o s i t i o n was d e s c r i b e d a s being a combination of hardpacked snow and l a r g e a n g u l a r chunks.

COMMENT

The v i c t i m was a l o c a l r a c e r and a member o f t h e v o l u n t e e r s k i p a t r o l . He s e t t h e t h i r d g a t e i n a flagged non-skiing a r e a of t h e

mountain, where t h e snowpack was probably r a r e l y d i s t u r b e d and t h e r e f o r e prone t o deep i n s t a b i l i t y . Avalanches a r e r a r e a t t h e S i l v e r S t a r Ski Area and it i s n o t s u r p r i s i n g t h a t t h e v i c t i m ' s companion thought nothing of t h e "breaks" h e saw i n t h e snow n e a r t h e g a t e .

A f t e r t h e a c c i d e n t some b u l l d o z e r work was done i n t h e g u l l y with t h e e x p e c t a t i o n o f reducing t h e h a z a r d , b u t avalanche c o n d i t i o n s s t i l l develop on an i n f r e q u e n t b a s i s .

S K I TRACK OF V I C T I M , PREVAILING ROAD 0 ROCKY I

\

" \

\

LOCATION OF BURIED BODY

OCEAN FALLS, B.C. 13 JANUARY 1965

Seven r e s i d e n t s k i l l e d , f i v e i n j u r e d , s e v e r a l b u i l d i n g s d e s t r o y e d

LOCAT I ON

The town of Ocean F a l l s i s a t s e a l e v e l on t h e P a c i f i c Coast

about 500 km northwest o f Vancouver, B . C . The c l i m a t e i s v e r y wet with a mean annual p r e c i p i t a t i o n of 4400 mm.

WEATHER

O b s e r v a t i o n s a t Ocean F a l l s Townsite 5 m ASL

Temperature P r e c i p i t a t i o n

O C

Date Max Min mm

9 J a n u a r y 1 -5 10 10 J a n u a r y 1 . 5

-

Between 31 December and 8 J a n u a r y 136 cm o f new snow was r e c o r d e d a t Ocean F a l l s . Extremely heavy r a i n f e l l a t t h e t o w n s i t e on

13 J a n u a r y . ACCIDENT SUMMARY

The t h r e a t o f f l o o d i n g and s l i d e s became p r e v a l e n t a s heavy r a i n f a l l c o n t i n u e d d u r i n g t h e evening o f 13 J a n u a r y . A t 2030 h t h e western end o f t h e ground f l o o r a t t"I'he Willowstt a p a r t m e n t s was

flooded by s l u s h and w a t e r . The Royal Canadian Mounted P o l i c e a s s i s t e d t h e t e n a n t s t o e v a c u a t e t h e b u i l d i n g . Because o f t h e i n c r e a s i n g

avalanche h a z a r d t h e P o l i c e a l s o decided t o c l o s e t h e road between t h e t o w n s i t e and Martin V a l l e y , a s u b d i v i s i o n 1 . 5 km west of t h e town. A t approximately 2130 h power and t e l e p h o n e communications were i n t e r r u p t e d .

At 2200 h an avalanche came down a gully from Mt. Caro Marion

carrying trees, mud and boulders. At the lower end of the gully it

separated into three arms, two of them followed watercourses on the

alluvial fan. The arm in the westerly creek destroyed half a duplex

house above Burma Road, knocked down the porch of a second duplex and

finally demolished the end rooms on a bunkhouse at the water's edge.

The easterly arm struck and completely destroyed another duplex above

Burma Road, carried the wreckage downhill and struck the print shop and

Credit Union buildings below. Both were destroyed and two adjacent

buildings were partially damaged. The wooden roadbed of Burma Road was

also torn out by the avalanches.

Three of the seven persons residing in the western duplex were

trapped in the undestroyed portion of the home. The other four persons

and the three persons residing in the eastern duplex were engulfed by

the avalanche.

RESCUE

Police officers and volunteer rescuers were working at the

Willows Apartments just east of the accident site when the destructive

avalanche occurred. The rescuers immediately began a search of the

avalanche debris, freed the three trapped persons, and recovered two

bodies within one-half hour after the avalanche. The injured persons

were evacuated to the town hospital where an emergency power system had

been set up. The paper mill was shut down when news of the disaster

was received, and the workers joined the rescue parties. The townspeople

living around the avalanche area were advised to leave their homes and

take refuge at the hotel or the mill. Those residents in areas cut off

by the slide were evacuated to safe positions by boat. At 0200 h on

14 January another avalanche which ran down between the two earlier

tongues occurred. Rescue efforts were called off until dawn.

The ship Northland Prince arrived on its regular run at 0430 h and

stayed in port until the damage and further potential danger could be

assessed. At dawn the rescue effort was renewed. It was extremely

slow going because of the mixed snow, mud, rock, and wrecked timbers.

The long-distance telephone communication was reestablished at 0700 h.

The search continued for several days until the last two bodies

were recovered 19 January. In all seven persons were killed and five

injured

.

AVALANCHE

Mt. Caro Marion rises to an elevation of 1234 m above the Ocean Falls

townsite. The avalanche path in question starts at an elevation of

approximately 915 m on the south slope of the mountain and runs over

much of its vertical fall in a rock canyon approximately 25 m wide.

The average gradient in the canyon is approximately 45'.

The avalanche

of 13 January started in the canyon between 400 and 500 m elevation. The

canyon opens into an alluvial fan over a talus slope at approximately

120 m elevation.

The avalanche was the result of heavy snowfalls in early January

followed by high temperatures and heavy rain on 13 January. Local

residents mentioned a freezing rain in December which coated the town

with ice. The ice layer, when lubricated by the rain, might have

provided an initial sliding surface for the deep snow. The avalanche

was probably triggered by wet snow sluffing from the canyon walls, and

once in motion collecting additional wet snow, mud, boulders, and

trees.

Several other avalanches ran on Mount Caro Marion during the same

night, but caused no damage other than blocking the road to Martin Valley

in four places.

COMMENTS

The avalanche 13 January 1965 was an unusual occurrence caused by

a combination of adverse weather factors. Such avalanches might only

be observed once in 50 to 100 years. The older residents of Ocean Falls

could not remember avalanches reaching the townsite before. The only

large avalanches in memory were two of mixed snow and mud that crossed

the Martin Valley road

December 1957. That day 216

of rainfall was

recorded.

This case illustrates the need for zoning studies before a

subdivision is built. The avalanche tracks above the residential areas

can easily be recognized, and from studies of the terrain, the tree

growth, past avalanche activity, and calculations of the theoretical

runout distance the extent of any possible large avalanche could have

been determined. Either no buildings should have been placed in the

dangerous zone or defences should have been provided for their

protection.

After the accident small dikes were bulldozed along the track of

the destructive avalanche, but they were no longer evident in 1978.

F i g u r e 4 Mount Caro Marion and t o w n s i t e w i t h t h e a v a l a n c h e t r a c k i n t h e c e n t r e

ROCK CANYON

Y\

MATURE TIMBER;

SLOPE INCLINE 30" _{MATURE TIMBER;}

SLOPE INCLINE 30"

COUS I NS I NLET

Figure 5 Sketch map of t h e a c c i d e n t s i t e showing t h e e x t e n t o f t h e avalanches

MT. ST. ELIAS, YUKON TERRITORY

11 AUGUST 1971

Four climbers killed

On 11 August, after completing ascents on Mt. Logan, five members

of an expedition party attempted an ascent of Mt. St. Elias from the

Newton Glacier via Russel Col, the original route climbed by the

Duke of Abruzzi at the turn of the century.

WEATHER

During the afternoon o$ 11 August the temperature was above 0°C and

it was sunny although the NE face of St. Elias was in the shade. The

climbers had observed extensive avalanche activity on the south-facing

slopes of Mts. Newton and Jeannette but not on St. Elias or Russel Col.

There was, however, evidence of old avalanche tracks and depositions on

these slopes.

ACCIDENT

At approximately 1600 h the climbers, travelling on two ropes, were

about 90 m above the Newton Glacier on the 750 m high slope leading to

Russel Col. Hearing a loud crack the climbers looked up and saw an

avalanche coming off the NE face of Mt. St. Elias and spreading across

the slope above them. The group attempted to dig in, but the entire

party was swept away within 5 or

seconds. When the avalanche had

stopped only one climber (who was on the lead rope) and a stuffsack

remained on the surface.

RESCUE

After unsuccessfully attempting to pull up the buried rope and to

dig with his hands, the survivor, in a state of shock, headed back down

the route without pack, snowshoes, or ice axe. He collected some food

from the party's cache on the Newton Glacier, as well as from the

caches of other expeditions, and headed for the main cache on the

Seward Glacier. After spending the night on Newton Glacier he arrived

at the Seward Glacier cache late on 12 August and radioed the Arctic

Institute of North America station at Kluane Lake. The following day

he was picked up by helicopter and flown to Kluane Lake. The bodies of

the other climbers were not retrieved because of their remote location

and the hazardous conditions.

AVALANCHE DATA

The avalanche was initiated by glacial ice blocks breaking off the

steep slopes to the south of Russel Col at approximately the 3400 m

l e v e l . As l a r g e amounts o f wet snow were p i c k e d up d u r i n g t h e motion o f

t h e a v a l a n c h e , i t c o n s i s t e d o f mixed wet snow and i c e b l o c k s . The

d e p o s i t i o n , which s e t t l e d and hardened v e r y q u i c k l y , was 60 m wide,

20 m l o n g , and 2 t o 3 _{m deep.}

COMMENT

The s u r v i v o r f e l t t h a t t h e p a r t y s h o u l d have r e c o g n i z e d t h e

a v a l a n c h e danger i n view o f t h e o l d d e p o s i t s and c u r r e n t a c t i v i t y , b u t t h e absence o f any a v a l a n c h e s r u n n i n g n e a r t h e c l i m b i n g r o u t e on t h a t p a r t i c u l a r day made t h e c l i m b e r s f e e l c o n f i d e n t .

REFERENCE

American Alpine Club and Alpine Club o f Canada; A c c i d e n t s i n North American Mountaineering, 1971.

Y - , ( HALL PARTY )

NINE MILE MTN., n e a r HAZELTON, B . C . One snowmobile o p e r a t o r k i l l e d WEATHER O b s e r v a t i o n s a t New H a z e l t o n c l i m a t e s t a t i o n . 313 m ASL Temperature

"

Date Max Min mm

10 March 5 . 5 0 . 5 3 . 0

11 March 7 . 0 0 T r a c e

12 March 6 . 0 -0.5

1 3 March 6 . 0 -5.5

14 March 8 . 5 - 1 . 0

S e v e r a l days o f f r e e z e - t h a w had been e x p e r i e n c e d a t Nine Mile Mountain. On 14 March t h e snow s u r f a c e was f i r m i n t h e d r e a .

ACCIDENT SUMMARY

A p a r t y on s i x snowmobiles l e f t Hazelton 14 March t o spend t h e day

a t a c a b i n on Nine Mile Mtn., a p p r o x i m a t e l y 10 km n o r t h e a s t o f

H a z e l t o n . The group t r a v e l l e d p a r a l l e l t o Two Mile Creek t h e n ascended by r o a d t o t h e c a b i n a t t h e 1475 m l e v e l . In t h e a f t e r n o o n t h e y

d e c i d e d t o s o r t i e n o r t h a l o n g t h e west f a c i n g s l o p e a t Nine Mile Mountain

.

Two snowmobiles were l e a d i n g a c l i m b i n g t r a v e r s e below t h e r i d g e , one s l i g h t l y ahead and above t h e o t h e r . Suddenly t h e second d r i v e r n o t i c e d snow washing up a g a i n s t h i s machine and l o o k i n g ahead saw t h a t t h e o t h e r v e h i c l e was a l s o b e i n g washed by a v a l a n c h i n g snow. The l e a d d r i v e r was r u n n i n g a l o n g on t h e u p h i l l s i d e o f h i s machine, presumably t r y i n g t o p r e v e n t i t from r o l l i n g o v e r . R e a l i z i n g what was happening t h e second d r i v e r opened h i s t h r o t t l e and t u r n e d d o w n h i l l w i t h t h e a v a l a n c h e . A f t e r momentarily l o s i n g c o n s c i o u s n e s s he found h i m s e l f

s i t t i n g with h i s machine a few metres from t h e edge o f t h e avalanche

d e p o s i t i o n . There was no evidence o f t h e l e a d machine. The time was

approximately 1600 h . RESCUE

The second d r i v e r immediately proceeded t o a s p o t i n t h e avalanche d e p o s i t about 25 m away, n e a r t h e base o f some small t r e e s , and began t o d i g . A few moments l a t e r t h e o t h e r f o u r d r i v e r s , who had been w a i t i n g i n t h e s a d d l e n e a r t h e c a b i n , a r r i v e d . Asked why he was digging i n t h a t p a r t i c u l a r s p o t t h e second d r i v e r could o n l y answer t h a t he knew t h e v i c t i m was t h e r e . One machine r e t u r n e d t o t h e cabin f o r s h o v e l s and f i r s t a i d equipment.

I

J u s t a s t h a t machine r e t u r n e d t h e second d r i v e r l o c a t e d t h e s k i o f

h i s companion's machine about 1.5 m below t h e s u r f a c e . The group

continued digging with s h o v e l s and found t h e v i c t i m f a c e u p , b l u e and n o t b r e a t h i n g , underneath t h e overturned snowmobile 2 . 2 t o 3 _{m below} t h e snow s u r f a c e . Approximately 40 minutes had e l a p s e d s i n c e t h e

a c c i d e n t occurred. Removing t h e v i c t i m from t h e h o l e was v e r y d i f f i c u l t because t h e snow had s e t l i k e cement. A t r a i n e d f i r s t a i d man i n t h e group attempted cardio-pulmonary r e s u c i t a t i o n b u t t o no a v a i l . The body was taken t o Hazelton on a f i r s t a i d toboggan t h a t had been s t o r e d a t t h e c a b i n .

I

The l a r g e d r y snow avalanche c o n t a i n i n g both a s l a b and a broken c o r n i c e was probably t r i g g e r e d by t h e passage o f t h e snowmobiles. The

f r a c t u r e l i n e had a maximum depth o f 4 m, and t h e avalanche r a n on o r n e a r t h e ground. Wind d u r i n g t h e w i n t e r had scoured t h e r i d g e and d e p o s i t e d t h e snow on t h e avalanche s l o p e . The m a j o r i t y of t h e

avalanche snow, both chunky and f i n e i n t e x t u r e , was d e p o s i t e d a t t h e s l o p e t r a n s i t i o n .

I

The s l o p e i n q u e s t i o n was f a i r l y s h o r t and was d e s c r i b e d by t h e s u r v i v o r s a s n o t being p a r t i c u l a r l y s t e e p . I t was s t e e p enough, however, t o s u s t a i n some c o r n i c e development along t h e r i d g e , a s u r e s i g n o f p o t e n t i a l avalanche hazard. The group found t h e snow s u r f a c e f i r m enough t o allow walking, b u t perhaps a snowpit o b s e r v a t i o n would have r e v e a l e d deep i n s t a b i l i t y .

Eye w i t n e s s o b s e r v a t i o n s about t h e v i c t i m ' s l a s t seen p o i n t , and any s u r f a c e c l u e s a r e c r i t i c a l i n l o c a t i n g r a p i d l y b u r i e d p e r s o n s .

In t h e p r e s e n t c a s e t h e second d r i v e r must have subconsciously recorded t h e l o c a t i o n where t h e f i r s t d r i v e r disappeared which l e d him

N- _{ALMOST NO DEFINED FRACTURE}

FRACTURE APPROX 4 m AND CORNICE BREAK

APPROX 300 m

+

X LOCATION OF THE SECOND DRIVER WHEN THE AVALANCHE STARTED

@ LOCATION OF THE SECOND DRIVER AFTER THE AVALANCHE

- - -

WESTCASTLE SKI AREA, ALBERTA

One machine damaged, operator injured

13 FEBRUARY 1975

WEATHER

Observations taken at Westcastle Day Lodge, 1415 m

ASL

Temperature Precipitation Snow Foot Wind "C Depth Penetration (est

.

New Storm Snow Snow

Date Time Max Min cm cm cm

cm

9 February p.m. 14

10 February 0630 0 -15 13 no obs. 113 55 light S

1830 -4 -19 12 33 119 5 8 light - m0d.N 11 February 0640 -19 -22 6 3 7 122 62 mod. NW

1945 -20.5 -22 2 2 5 7 138 78 light N 12 February 0630 -21 - 2 2 16 no obs. 152 78 calm

1945 -18.5 -22.5 39 93 175 120 light - mod.SW 13 February 0630 0 - 16 6 8 6 164 no obs. light - mod.NW

1825 1 -14 9 85 162 107 mod. NW

At approximately 2000 h on 12 February a warm air mass, which had earlier enveloped the upper mountain, sank to the Day Lodge at the base of the ski area causing the temperature to rise 13.S°Cin a few minutes. On 12 and 13 February observers at the top lift station reported moderate and gusting winds from the southwest.

A snowprofile taken 9 February at the top of Shotgun Gulch (1800 m elevation, ENE aspect) revealed 50 cm of temperature-gradient snow near the ground, overlain by 1 m of equitemperature snow and partially

AVALANCHE OBSERVATIONS

10 February

Explosive control produced numerous avalanches and

extensive settlement.

11 February

Controlled avalanches on N, NE, and E exposed slopes

(including Shotgun Gulch).

12 February

Controlled small avalanches on N, E slopes; one 25 cm

deep fracture on NE exposure.

ACCIDENT SUMMARY

In mid-February 1975 the Canada Winter Games were held at

Westcastle Ski Area. A storm began

February and by 12 February a

large amount of new snow had accumulated. The visibility at the

avalauncher gun at the top of the T-bar lift station was limited to

200 m. Due to the poor visibility and an expectedly high number of

unexploded projectiles, the avalauncher gunner did not want to fire

blindly. Control by hand charges along an alpine route was attempted

but was abandoned because of the avalanche hazard and poor visibility.

On the morning of 13 February the visibility had improved although

Chinook conditions prevailed in the alpine region. At 0730 h the

avalanche control team noted an abrupt temperature increase while

ascending the T-bar lift. The first avalauncher shot was fired into

the south side of the North Cirque and released a large avalanche which

ran down Shotgun Gulch to the Bunny Hill (Figure

A second shot was

fired into the north side of the North Cirque resulting in a second,

larger avalanche that destroyed the old upper lift base then moved down

Shotgun Gulch, crossed the Bunny Hill, and struck a grader on the road

below. The force of that avalanche blew out the windows of the grader

and snow pinned the operator against his seat.

RESCUE

Only about 50 cm of snow was deposited around the grader wheels so

rescue workers were able to free the operator from the cab then drive

the grader clear of the avalanche path. The grader operator was taken

to the hospital with minor injuries. A helicopter parked on a

temporary pad just below the road was not affected by the avalanche.

AVALANCHE DATA

Both avalanches of 13 February ran on a lubricating layer of 15 cm

of light dry snow which was deposited at the beginning of the storm.

The second avalanche started at an elevation of approximately 2050 m

and ran out at an elevation of approximately 1400 m. The first

fracture occurred on a slope with an ENE aspect and the second on an

ESE slope.

COMMENT

It should not happen that a vehicle be in the path of avalanches that are released by gunfire. This accident occurred because of lack of communication between the avalanche control team and the grader operator. Strict control of traffic, including private vehicles, maintenance

equipment, and skiers is an essential part of avalanche control by explosives. The measures include radio contact between the control personnel, road blocks, and maintenance vehicles.

The avalanche control team at the Westcastle Ski Area did not expect the second avalanche to be as large as it was. In theory the first avalanche, starting at a leeward slope and picking up unstable snow in the track, should have had a greater volume than the second, but the snowfall, together with high temperatures and a moderate wind of variable direction appeared to have deposited deep, rather cohesive

snow at the Northside of the Cirque, and this snow fractured over a wide area.

One of the objectives of control by gunfire is to release small avalanches through repeated firings during snow storms and thus prevent the formation of large, destructive avalanches. Unfortunately the old model avalauncher was unreliable for blind firing and the snow could not be released continuously in small amounts.

SECOND AVALANCHE Fl RST AVALANCHE

-N

SHOTGUN GULCH

ROAD

MT. FISHER, n e a r CRANBROOK, B.C. 11 J U N E 1976

Three mountain c l i m b e r s i n j u r e d

WEATHER

The sky was c l e a r and t h e t e m p e r a t u r e average d u r i n g t h e week p r i o r t o 11 June. The f o r e c a s t p r e d i c t e d t h e same weather would c o n t i n u e , however between 1130 and 1200 h on 11 J u n e a warm a i r mass s t r u c k t h e a r e a .

ACCIDENT SUMMARY

Three c l i m b e r s l e f t a logging road on Boulder Creek a t 0630 h f o r a climb on t h e North Face o f M t . F i s h e r , 2838 m e l e v a t i o n , over a mixed snow, i c e and rock r o u t e . Between 1130 and 1200 h w h i l e cramponing i n a snow c o u l o i r some 180 m below t h e peak, t h e group n o t i c e d a change i n t h e weather. The t e m p e r a t u r e began t o r i s e , mists began t o r o l l over t h e peak, and t h e snow began t o s o f t e n . About o n e - h a l f hour l a t e r t h e c l i m b e r s reached t h e t o p of t h e c o u l o i r where t h e y removed t h e i r

crampons i n a n t i c i p a t i o n of a s s a u l t i n g t h e f i n a l 60 m o f r o c k . A f t e r some d i s c u s s i o n t h e c l i m b e r s decided t h a t i n view of t h e i n c r e a s i n g avalanche h a z a r d t h e y should descend r a t h e r t h a n c o n t i n u e . Descending through t h e c o u l o i r t h e group reached an open snow s l o p e and stopped t o d i s c u s s t h e i r n e x t move. The o p t i o n s were e i t h e r t o wait f o r a f r e e z e - u p o r t o c r o s s t h e snow s l o p e . Choosing t h e l a t t e r t h e y t r a v e r s e d t h e snow s l o p e w i t h two r o p e s j o i n e d , b e l a y i n g from a s a f e p o s i t i o n . The ropes were n o t q u i t e long enough f o r t h e l e a d climber t o r e a c h a s a f e s p o t b e f o r e t h e middle c l i m b e r had t o advance even though t h e l e a d c l i m b e r was s t i l l moving. The l e a d c l i m b e r had j u s t reached t h e f a r s i d e of t h e snow f i e l d and was i n t h e p r o c e s s of p u t t i n g i n a f i r m b e l a y , when t h e middle man, a f u l l rope l e n g t h behind, was h i t by a s m a l l , f a s t avalanche and c a r r i e d downslope. The l e a d c l i m b e r ' s b e l a y h e l d t h e middleman, b u t t h e t h i r d c l i m b e r was p u l l e d o u t o f h i s i c e axe b e l a y and f e l l o n t o rock and snow below. The rope between t h e l e a d and t h e middle c l i m b e r t h e n broke and t h e middle and t h i r d c l i m b e r s continued t h e i r f a l l . When t h e y came t o r e s t t h e two men were s t i l l roped t o g e t h e r , were s u f f e r i n g from v a r i o u s i n j u r i e s , and t h e i r helmets were b a d l y damaged.

RESCUE

A f t e r r e g a i n i n g t h e i r w i t s t h e two c l i m b e r s decided t o p a r t . One would climb with a l l t h e s p a r e c l o t h i n g t o t h e person above, who had c a l l e d down s a y i n g s h e was h u r t , w h i l e t h e o t h e r would go f o r h e l p . The time was about 1400 h . The descending c l i m b e r reached a house a t 1800 h