Kevin McPhedran Mark Brown Ben Ferrel Keri Laughlin

Fall 2007

Geography 477

University of Victoria

Fall 2007

Environmental Hazards of Avalanches: Preliminary Research in Glacier National Park

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TABLE OF CONTENTS:

1. Abstract........................................................................................................................................3

2. Introduction.................................................................................................................................3

3. Study Area ..................................................................................................................................4

4. Methodology

4.1. Dendrochonological Study...........................................................................................5

4.2. Historic Selkirk Range Avalanches and Climatic Influences on Snowpack................8

4.3. Human Backcountry Use in Glacier National Park......................................................8

5. Results.........................................................................................................................................9

6. Discussion

6.1. Dendrochronological Study........................................................................................10

6.2. Historic Selkirk Range Avalanches and Climatic Influences on Snowpack..............13

7. Human Hazard and Park Policy.................................................................................................23

8. Conclusions................................................................................................................................29

9. References..................................................................................................................................31

Appendix.......................................................................................................................................35

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1. Abstract

The death of 7 students in an avalanche while on a school sanctioned backcountry skiing

trip in Balu Pass, Glacier National Park caused many individuals to question the status of risk

management within Canadian National Parks. The Balu Pass region adjacent to the Rogers Pass

National Historic Site in Glacier National Park was studied in order to determine if adjustment to

planning and zoning policies would prevent such tragedies. A dendrochronological study of the

Grizzly mountain avalanche path was conducted to determine the frequency of high magnitude

avalanche events. This data, along with anecdotal data regarding past avalanche fatalities, was

correlated with climatic data to determine the conditions leading to avalanche tragedies in the

greater Selkirk Mountain region. Avalanche risk, awareness and education and Parks Canada

policies regarding the planning and zoning of land within park boundaries were also investigated.

Based on the results of this multi-faceted study, suggestions were presented with the goal of

improving the effectiveness of National Park management with regards to preventing future

avalanche tragedies.

2.Introduction

Avalanches have been a significant hazard to human development and recreation in the

Selkirk Mountains ever since the Canadian Pacific Railroad first surveyed the mountain range in

the early 1880's. Roger's Pass was the biggest obstacle due to its exposure to avalanche terrain.

Over the last 120 years, humans have increasingly travelled across Roger's Pass- first in train,

and since the early 1960's, via the Trans Canada Highway. Originally the pass was only

accessible to train passengers stopping at the Glacier House Lodge, effectively limiting the

number of winter backcountry users. However, the construction of the highway greatly

increased the number of visitors to the pass. Today this high elevation pass (1330m a.m.s.l.), and

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associated developments including hotel and parking, allow for easy access for backcountry

skiers to what has become world renowned terrain. Located within Glacier National Park, the

high intensity backcountry use and the often extreme avalanche hazard make for difficult

planning conflicts for park managers. The Connaught Drainage basin and the Balu Pass trail

system are located adjacent to the highway and provide backcountry users with the most easily

accessible backcountry skiing along the Trans Canada Highway. However, the avalanche hazard

has not significantly changed since Rogers Pass was first surveyed and the danger continues

today to provide risk to users in the backcountry. The Canadian Avalanche Association and

Parks Canada have rated avalanche terrain within the park based on the three class Avalanche

Terrain Exposure Scale. In the Connaught Drainage basin, located within easy access of the

hotel and highway, most of the terrain (including Balu and Bruins Pass), is rated Complex, the

highest rating while the Grizzly Shoulder is rated class 2- Challenging (Avalanche Terrain

Ratings, 2007) (See Figure 8).

The purpose of this report is to do a preliminary exploration of several aspects of the

human related risks within the related field of avalanche science. These aspects include studying

the climatic and avalanche history of pass, in which dendrochonological analysis will be used.

Next, human loss of life as a result of avalanche activity will be explored in comparison to

scientific data collected, with emphasis on snow slides resulting in human deaths in the Selkirk

Mountains near Roger's Pass. Finally, park planning, zoning and decision making will be

discussed in relation to avalanche hazard, rescue and education.

3. Study Area

Roger's Pass is located in Glacier National Park which is located in the Selkirk Mountain

Range, a sub-range of the Columbia Mountains of south-central British Columbia. The location

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of field work was in the Grizzly Slide path on the slopes of Grizzly Mountain in the Connaught

Drainage Basin, otherwise known as the Balu Valley. The region is located in the Interior Wet

Belt climatic zone with relatively mild temperatures and abundant rain and snow (Parks Canada,

2005). Secondary research was conducted for other areas of the park, as well as locations

adjacent to the park in the surrounding Selkirk Mountains. (See figures 1,6 and 7 for location

maps, Figures 2-5 for photographs)

4. Methods

4.1 . Dendrochronological Study

Tree Core Collection

The study site was approached via Balu Pass Trail from the Rogers Pass visitors center.

Views of the study area from along the trail provided several different perspectives to survey the

avalanche track. This aided in choosing a location to collect our tree cores. Two days were

allotted to collecting samples. The slide track was sampled on day one and the edges of the run-

out zone was sampled on day two.

Day one: The goal for sampling the slide track was to capture tree ages along a transect

perpendicular to the slide track. The narrowest section of the slide track was chosen for the

transect which was located in the upper portion of the slide track. The transect began from a

creek bed approximately in the center of the slide track. The four members of the group were

split into two, with each team heading from the creek in opposite directions. The first tree

encountered was considered the innermost limit of the forested portion of the track. The

steepness of the terrain and density of slide alder between the creek bed and the first tree

prevented accurate measurements of the distance between the tree and the creek bed; therefore

the distance was roughly estimated instead. The trees along the transect were then selectively

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sampled based on proximity to the line of the transect. Distances were estimated between each

sampled tree and the first tree sampled. Sub-alpine fir was the dominant tree species present in

the area and consequently, only sub-alpine fir were sampled. The transect progressed until we

reached mature forest outside of the slide track. (See Figure 9)

Day Two: The goal for sampling the run-out zone was too capture the age distribution of

the tree growing on the edges of the zone. Again, the group split into two and each group

sampled opposing sides of the run-out zone. A somewhat random method of sampling was used,

and a general description of the location of each tree sampled was noted in the field notes. The

first tree encountered was sampled, and then trees were sampled progressively outward and

towards the upper edge of the run-out zone.

Coring

Tree cores were always taken from the most down slope location on the tree which

afforded a stance suitable for core sampling. When possible, scars were cored by coring through

the bark on the outside of the scar at a slight angle towards the scar. All cores which did not

contain a portion of the pith were discarded. Trees with a J-shape at the base were always cored

where the tree began growing straight again, above the curvature.

Preparation and Analysis of Tree Cores

Tree cores gathered in the field were glued into wooden holders and sanded to

approximately half of their initial diameter. Each holder was then digitally scanned and saved in

jpeg format. The images were then cut into four sections, each containing a single core, and each

section was saved as an individual file.

Each image was then imported into WinDendro. In order to count the rings in

WinDendro, first a line was drawn from the pith to the bark. WinDendro then automatically

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attempted to count the rings based on variations in the tone of the wood. A manual check was

done on this ring count, and any missed rings were added and corrections were made for mis-

placed rings. Based on the number of rings counted, a range of years during which the tree

produced its first ring was recorded. This range was chosen based on the apparent level of

uncertainty in the ring count. Broken cores, rotted sections, very small rings, and disturbances in

the wood all created uncertainty in the ring count. The technician performing the analysis made

the final count, and therefore had the task of deciding the cumulative uncertainty on a ring count.

Scott Jackson, a local expert in dendrochronology, was consulted to determine which

disturbances observed in the cores were in fact scars. These scars were assumed to have been

caused by avalanches. The number of rings between the scar and the bark were counted, and the

year the tree developed the scar was recorded.

In cases where rotting or an unknown physical disturbances had altered the growth of the

tree to the point where it was impossible to derive any meaningful data from the rings, the core

was discarded.

Tree Core Collection and Analysis

The raw data collected was grouped into clusters of observations. These clusters were

determined by observing separation between the upper and lower boundaries assigned to core

ages. Each cluster represents a group of observations where the separation between all members

is equal to, or smaller than the separation between the closest member of the next cluster. The

clustering of observations was performed in order to determine periods where trees were

beginning to recolonize a region after an event which removed the previous generation.

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4.2 Historic Selkirk Range Avalanches and Climatic Influences on Snowpack

Past avalanches in the Selkirk Mountain Range were studied in order to gain an

understanding of snowpack instabilities that result in avalanche risk in Glacier National Park.

Three years with significant snowpack instabilities were studied for climate influences,

snowpack stability and resulting human accidents in the region, and thus natural factors that are

important contributions to avalanche risk could be evaluated.

Climate data collected for the study was made available through Environment Canada's

online National Climate Data and Information Archive. (Environment Canada, 2007) Data used

are from the weather station located above Roger's Pass on Mt. Fidelity at an elevation of

1874.5m, latitude 51o 14.400' N, longitude 117

o 42.000' W. These data are assumed to be

representative of the weather conditions at both the study site in the Connaught Valley and for

locations of avalanche fatalities in the Selkirk Mountains within close proximity of the station.

Dendrochronological studies in the Grizzly Slide path located obvious scars created by

avalanches, and the year that these avalanches occurred. Avalanche history in the Selkirk

Mountains was then researched in these years, as well as in years known to have unstable

snowpacks, using historical records from the Canadian Avalanche Association (Jamieson and

Geldsetzer 1996) and other accounts. Historical records were limited to events with fatalities,

and climate data was used in an effort to explain climate and snow conditions that contributed to

the avalanche accidents that happened in the winters of 1987-1988, 1992-1993 and 2002-2003.

4.3. Human Backcountry Use in Glacier National Park

The majority of data was collected upon return from field research in Balu Pass, Glacier

National Park. Human Data was collected with a focus on 3 main factors: a) Avalanche incidents

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involving fatalities, b) trends and patters of both human and environmental factors, and c) visitor

use within the park boundaries.

Research and analysis were sourced from a number of published research articles, B.C.

and Canadian statistics on available avalanche accidents involving human fatalities, phone and

email interviews conducted with a number of C.A.A, Search and Rescue (SAR‟s), and Parks

Canada employees, as well as information gathered at the most recent SARSCENE conference in

Victoria, B.C (October 9-12th

, 2007).

5. Results

Dendrochronological study

Table 1: Summary of data from Dendrochronological Study of Grizzly Mountain

avalanche path, Rogers Pass, BC

Number of Samples Number of Scars

Date Range of Samples Max age In range

2 1863-1866 144

3 1883-1990 124

2 1924-1925 83

7 2 1940-1948 67

6 3 1964-1968 43

6 1973-1978 34

4 1 1981-1985 26

3 2 1988-1991 19

4 1993-2001 14

Table 2: Summary of Avalanche Fatalities in Selkirk Mountains Discussed

Date Location of Slide in

Selkirk Mountains

Number of

Casualties

Bed Surface

1987-88 Standfast Creek 1 surface hoar

1987-88 Sale Mountain 1 surface hoar, graupel

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1992-93 Bruins Pass 1 faceted layer

2002-03 Durrand Glacier 7 November rain crust

2002-03 Mount Cheops / Balu

Pass

7 November rain crust

See Appendix for Climate Graphs and Maps

6. Discussion

6.1 Dendrochonological Study

The oldest trees sampled were approximately 140 years old. These trees occurred

between avalanche paths in mature forest that was relatively uniform in age. This region of forest

did not appear to be affected by large avalanches originating in the alpine basin of Grizzly

Mountain. This generation of trees may have formed after a large event cleared the valley of

vegetation, such as a wildfire.

The boundaries between the age classes in the trees were not well defined but in general,

the age of the sampled trees increased with distance from the center of the avalanche track. The

ages of the sampled trees occurred in clusters (see table 1) which will be referred to as age

classes. These age classes are thought to have developed due to forest regeneration after the

removal of a previous generation, where the frequency of removal varies with location. Fire,

debris flows and avalanches are all potentially responsible for the removal of trees from the

perimeter of the gully draining Grizzly basin. However, due to the lack of either fire or debris

flow scars having been observed, large avalanches provide a good explanation of the complete

removal of these trees. The sides of the gully are quite steep, and approximately 30m of

elevation is gained along the side of the gully before reaching the youngest stand of trees.

Estimated horizontal distance from the first tree encountered to the center of the gully was 50m,

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which gives the gully a cross-sectional area of approximately 1500m2. This assumes that the

gully is symmetrical and places the upper bound at the elevation of the first tree encountered.

Therefore, an avalanche which removes trees along the sides of the gully must fill the gully to at

least this height.

During an average winter, 932.5cm of snow falls at Rogers Pass, which is at an elevation

of 1330m, approximately 100m below the run-out zone of our study area. At Mount Fidelity,

which is at an elevation of 1874m, 1471.2cm of snow fall in an average winter. Avalanche

cycles occur after most large storms, and are mainly comprised of moderate to small sized

avalanches, depending on the amount of snow deposited during the storm. Avalanches

throughout the year deposit a large amount of snow along the avalanche track and run-out. This

deposition, combined with winter snowfall in excess of nine meters, fill the gully to an extent

which allows large avalanches to reach the younger stands of trees along the sides of the gullies.

A snowpack may become unstable as temperatures rise in the spring (Deems, 2002).

Freeze-thaw metamorphism occurs when temperatures rise well above zero during the daytime

and drop below zero at night. This process produces isothermal snow which often results in full

depth avalanches (Gardner, 1983). As the full depth of the snowpack becomes mobilized, entire

trees may be uprooted, leaving little evidence of the event once the tree is transported away from

the area. Snow in spring avalanches often contains a higher moisture content than mid-winter,

dry avalanches. Increased moisture content can make these avalanches extremely destructive to

objects which form barriers constraining their movement. An example of such a barrier is the

perimeter of a forest.

The sampled region of the avalanche path contained a variety of ages, beginning with

younger trees with greater age variation nearest to the center of the avalanche track. The trees

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gradually became older and more uniform as distance from the center of the track increased. The

greater variation in age of the youngest class is thought to be the result of higher avalanche

frequency in this region (Shaerer, 1972). Variation within the older classes is smaller and

thought to represent the duration of recolonization after a larger, more destructive event. The

oldest age in the class is therefore thought to have taken root the summer after the destructive

avalanche occurred (Shaerer, 1972). Where slide alder is the only vegetation, avalanches occur

too frequently for trees to grow. According to tree ring growth analysis, fourteen years have

passed since the last avalanche destroyed any of the trees along our transect. The largest

magnitude avalanche to occur in this region appears to have a recurrence interval of at least 83

years, with several other recurrence intervals of smaller magnitudes of avalanches. (See Figure

10) This assumes that the two oldest age classes represent mature forest and are unaffected by

avalanches.

Several difficulties were encountered in the field that deserve mention. From the trail at

the base of the avalanche path, there appeared to be several distinct age classes in the trees as the

distance from the center of the slide path increased. The field work was intended to provide a

measurement of the age of these classes as well as their distance from the center of the slide path.

However, once the edge of the forest was reached, it became apparent that the clear boundaries

observed from a kilometer away were actually somewhat staggered and outliers of much older

trees existed in the younger stands.

Difficulties were also encountered in the lab. The lab technicians responsible for

counting the annual growth rings in the cores had no prior experience doing this. Many of the

cores had disturbances along the length of the core which added some uncertainty to the number

of rings counted. The experience gathered throughout the course of the lab analysis was drawn

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on to decide on the degree of uncertainty in the age of a core. The range of ages used was

slightly larger to compensate for the lack of expertise, and for tree age counts, there was an

average age range of 3 years.

6.2 Historic Selkirk Range Avalanches and Climatic Influences

1987-1988

Weather conditions in the Selkirk Mountains in the winter of 1987-1988 set up prime

conditions for avalanches to occur. As our dendrochonological study found, major avalanches

may have scarred trees during this winter in the Grizzly Slide path in the Connaught Drainage.

On January 17th, 1988 one heli ski guide was killed approximately 20km southwest of Mt.

Fidelity near Standfast Creek. Also, on March 22, 1988 two heli skiers were buried, one killed

in a slide on Sale Mountain (Jamieson and Geldsetzer, 1996) northeast of the town of Revelstoke

adjacent to Mount Revelstoke National Park, approximately 60km west of Mt. Fidelity. Both

slides could be attributed to slab avalanches sliding on a weak surface hoar layer as a result of

cold temperatures followed by heavy snowfall in the days preceding the snow-slides (Jamieson

and Geldsetzer ,1996), combined with human related factors such as choice of terrain.

The growth of surface hoar is a result of the same process that creates dew on a clear

summer evening. Surface hoar primarily develops on cold clear nights in the mountains, and can

create an extremely weak layer, which deposited snow can slide on. Daytime radiation heats the

column of air above snow and allows the air to hold significant amounts of moisture. When the

sun goes down on a clear evening the source of radiation is lost, and the snow surface cools

quickly while the air above becomes super saturated in comparison to the snow. Therefore, water

vapour condenses on the surface and creates crystalline "feather like" surface on the snow known

as surface hoar (Daffern, 1999; Birkland et al., 1998). These "standing, feather-like" crystals

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can create an extremely unstable layer when buried by snow, and is often this layer that fails in

an avalanche when the weight of snow above literally forces the standing crystals to fall over,

releasing the snow above down slope (Daffern, 1999).

Both avalanches resulting in fatalities in the Selkirk Mountains in 1988 were attributed to

the surface hoar that built up in the clear, cold conditions in the weeks leading up to the slides

(Jamieson and Geldsetzer, 1996).

January 17, 1988- Standfast Creek:

On January 17, 1988, a heli-ski guide triggered, and was ultimately killed in an avalanche

approximately 20km southwest of Mt. Fidelity in Glacier National Park on an east facing slope

above Standfast Creek (Jamieson and Geldsetzer, 1996). A snow profile dug at the site, in

combination with a review of the weather conditions leading up to the incident, provide a

detailed explanation of the snow conditions leading to the accident. The first week of January of

1988 was dominated by a cold, dry air mass in the Selkirk Mountains- daily lows were between -

21oC and -12

oC while daily highs ranged from -14

oC to -8

oC over the first 8 days of the month

and only 2cm of snowfall fell (Environment Canada ,2007) (See Figure 11). During this

period, a layer of surface hoar was observed to have been deposited on the surface (Jamieson and

Geldsetzer, 1996). Starting on the 9th of January and continuing until the 16th, several storms

deposited 123cm of snow on top of the surface hoar layer (Environment Canada ,2007).

Under scattered clouds on January 17th, one of the two heli ski guides began descending

a treed slope, and upon going over a convex roll, triggered a size 2.5 slab avalanche (Jamieson

and Geldsetzer, 1996). Somewhere between a size 2 avalanche, capable of burying, injuring or

killing and person, and a size 3 avalanche, capable of burying and destroying a car, damaging a

truck, or breaking a few trees (Jamieson, 2000) , a size 2.5 is not excessively large, however the

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trauma from being swept through the trees resulted in the fatality (Jamieson and Geldsetzer,

1996). Upon investigating the accident the following day, it was determined the slide broke

about 75cm down on a layer of surface hoar (Jamieson and Geldsetzer, 1996) that was the result

of the extended period of cold, dry weather early in the month.

Another contributing factor was the topography of the slope being skied. Avalanche

hazard is known to be highest on slopes between 30o and 45

o for slab avalanches (Daffern,

1999)- the slope that slide on this occasion was measured to be 35o (Jamieson and Geldsetzer,

1996). Furthermore, the slide was triggered on a convex roll in the slope. The rounded top of a

terrain feature can be a trigger zone for slab avalanches because tensile stresses in the snowpack

are greatest in the rounded portions of a convex slope as a result of snow creep on the steeper,

lower part of a slope (Daffern, 1999).

This avalanche occurred within about 10 to 20 days after the surface hoar was buried if it

is assumed that the surface hoar began to grow at the beginning of the cold, dry spell in January.

This is exactly the length of time researchers have found to be the most common time-lag for

avalanches to occur after the burial of surface hoar in the Columbia Mountains (Chalmers and

Jamieson, 2001). It is therefore of interest for avalanche forecasters to have a tool to test the

snowpack and determines when a weak, buried, surface hoar layer makes the transition from

unstable to stable. This is precisely what Chalmers and Jamieson (2003) attempted to do by

measuring several snowpack variables over time in several locations in the Columbia Mountains.

The result of their study is an empirical model that can be translated to an index between 1 and

10 where values of one to three indicate continued instability of the weak layer, four to six

indicates the layer is in transition from unstable to stable, and values between seven and ten

indicate stability of the layer (Chalmers and Jamieson, 2003). The development of an index

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such as this one is an important tool for avalanche forecasters to have in an effort to determine

the conditions that the public face upon entering the backcountry in places such as the mountains

in proximity of Roger's Pass.

March 22, 1988- Sale Mountain:

Not much more than two months later, a second heli-skiing fatality occurred in the

Selkirk Mountains. While some of the conditions leading to this accident were similar, other

complicating factors exist. The series of events leading to the fatality can be summarized as

follows (Jamieson and Geldsetzer, 1996):

-the lead guide began skiing down a 40o northeast facing slope and triggered a small (1.5)

avalanche, burying him under 40cm of snow

-one of the three other skiers in the group skied down to the point where the guide was last scene,

and upon finding the original victim, called for the two other skiers to help to dig him out

- when the final skier of the waiting group came down, he released a larger, size 2 avalanche,

burying the guide deeper (2.0m under), burying one of the skiers 1.2m and semi- burying the

final two skiers

- in the moments after the two avalanches, communications were made with the helicopter pilot,

and a resulting search team including guides on nearby mountains and avalanche technicians

from the Ministry of Highways and Transportation were able to find and transport all victims to

safety; however, the buried skier died of asphyxiation while the guide lived

An examination of the weather conditions leading up to the accident demonstrate the

possibility of unstable layers in the snowpack (See Figure 12). In the week prior to the accident,

from March 15-18, cold clear nighttime conditions persisted, with nighttime lows reaching -10oC

(Environment Canada, 2007) and created conditions for the growth a surface hoar. Then, over

the three days prior to the accident, 54cm of snow fell accompanied by a southwest wind

(Environment Canada, 2007; Jamieson and Geldsetzer, 1996). The combined snowfall and wind

would effectively load the northeast slope and form slab- a cohesive unit of snow. However, the

warm daytime temperatures (reaching 5.5o C and often above freezing) and southwest winds in

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the days leading up to the accident would destroy the surface hoar (Jamieson and Geldsetzer,

1996). The high daytime temperatures would strengthen the snowpack by melting the surface

hoar and increasing the bonds by melting crystals together, while wind would destroy the surface

hoard through the process of saltation (Daffern, 1999). These factors likely led the group to

believe conditions were safe. Nevertheless, the shading effect of the aspect of the slope

preserved the surface hoar layer (Jamieson and Geldsetzer, 1996). The first, size 1 avalanche

slide on a layer of graupel snow (well rounded due to collisions in the atmosphere from

turbulence) that fell during the recent storm (Jamieson and Geldsetzer, 1996). It was the second

slide, triggered by the "rescuers" that slid on the surface hoar layer at a depth of 60cm beneath

the original surface, deeper than the depth of snow that fell due to wind loading effects on that

aspect. It was this unstable layer that ultimately caused the fatal slide.

The localized conditions, such as wind direction and strength and aspect and shading,

make avalanche forecasting and field testing extremely difficult, as this case study has shown.

This exemplifies why digging a snow-pit in one location may not be a very good indicator of

snow conditions in a nearby location.

March 17, 1993 - Bruins Pass

On March 17, 1993 two skiers headed up Balu Pass trail in the Connaught drainage to

Bruins Pass (See Figure 7). Both skiers were experienced and decided to ski the east aspect of

Bruins Pass as an alternative to the south and west aspects of Little Sifton due to the potentially

dangerous sun crust which was earlier observed there. As they were approaching Bruins Pass, a

weak faceted layer in the snowpack failed and both skiers were caught in an avalanche. Skier

number one managed to avoid burial by the slide, skier number two was buried and killed. Skier

number one recovered skier number two from beneath the snow, however resuscitation was

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unsuccessful. Two days later an investigative team flew up in helicopter to the ridge to do a

fracture line profile; as they were skiing down to the site they triggered a larger avalanche. No

one was caught in the second avalanche. (Jamieson and Geldsetzer ,1996).

The first avalanche was due to a failure in a weak faceted layer in the

snowpack.(Jamieson and Geldsetzer, 1996). Weak facet layers are developed when the

temperature difference between the top and bottom of a layer in the snowpack is large. This

temperature difference, with respect to depth, is also known as temperature gradient. (Jamieson,

2000) When the temperature gradient is large "the gradient will draw water vapour up through

the snow layer, creating faceted grains and probably weakening the snow layer. If, however there

is little temperature difference...the gradient will not draw water through the snow fast enough to

cause faceting; the grains will become rounder and the layer will strengthen." (Jamieson, 2000)

So not only does a large temperature gradient cause faceting which weakens the layer, it also

prevents the snow from rounding and stabilizing, which would otherwise occur.

Snow faceting develops due to conditions that cause large temperature gradients in the

snowpack. Temperature gradients in the snow pack can become set up due to a variety of

climatic conditions. One example of these conditions is a relatively warm snow surface, buried

by a layer of colder snow. (Birkeland, 1998) Another climatic conditions that causes large

temperature gradients in the snowpack is sub-surface warming from short-wave radiation or

surface cooling from long wave radiation. These usually happen during warm, sunny days and

cold clear nights respectively. (Birkeland, 1998) In the case of the Bruins Pass avalanche, the

faceting that was present was likely due to a warm snow surface being buried by a subsequent

colder snowfall. A cold period following this burial would have developed the temperature

gradient further. On March 7, 1993, there was a five centimeter snowfall during warm weather-

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the temperature for the day ranged between -0.5oC and 2

oC. (Environment Canada, 2007) This

layer of relatively warm snow was then buried by four centimeters of colder snow the next day

when temperatures ranged from -2oC to -6

oC (Environment Canada, 2007). The warm snow

layer burial is circled in red on Figure 13 (in Appendix). The relatively warm, buried layer of

snow and the colder surface snow were then exposed to several days of cold temperatures. The

cold temperatures that followed the burial of the relatively warm snow layer would have caused

the surface snow to cool even further, increasing the gradient. These cold temperatures are

circled in blue on Figure 13.

After faceting occurred over several days there was a large snowfall. Faceted crystals are

often associated with thin, overlying crusts on southerly aspects which make them particularly

dangerous when those crusts are overloaded until they collapsed into the weaker, underlying

snow. (Stratton, 1977) The weak faceted layer that had now developed from the snowpack

temperature gradient was overloaded with 31 centimeters of snow on March 14th and then

another 21cm on March 17th, the day that the avalanche occurred. These hefty snowfalls are

circled in gold on Figure 13.

The March 17th avalanche occurred from a weak faceted layer failing. Jamieson and

Geldsetzer's account documents that the involved skiers observed a "sun crust on the south and

west aspects".(Jamieson and Geldsetzer, 1996) They took the melt-freeze crust danger variable

out of the avalanche hazard by skiing an east facing aspect. Unfortunately, the weather

conditions created a temperature gradient in the snowpack as a result of a buried layer of warm

snow and long wave-radiation cooling, which can occur on all aspects (Birkeland, 2004).

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2002-2003

Twenty-nine people were killed in Canadian avalanches in the 2002-2003 season in

Canada, fourteen of these were from two avalanches in the Selkirk mountains. This is the third

worst year in terms of avalanche fatalities after 1910 when 62 people were killed in Rogers Pass

on the railroad, and 1965 when 35 fatalities occurred, with 34 of those being industrial accidents.

(Avalanche Center) The alarming amount of deaths during the 2002-2003 season aroused a

significant investigation as to what went wrong and how accidents like these can be prevented in

the future. Both of the fatal avalanches that occurred in the Selkirk Mountains were blamed on

failure of the November rain crust.

British Columbia experienced unseasonably warm weather in November 2002

with precipitation in the form of rain falling on snow in mountainous areas. When

temperatures cooled, a significant melt-freeze crust was left on the snow pack.

This crust was present across the mountains of Western Canada from the Coast

Range to the Rockies and was particularly pronounced in the northern Selkirk

Mountains. (BC Coroners Service)

Melt freeze crusts are a common phenomenon associated with snowpack failures and

avalanches. "For decades, avalanche observers have noted that wet layers on the snow surface

that freeze into crusts subsequently form the bed surface for many slab avalanches." (Jamieson,

2004) When these crusts form it is actually the weak bonding between the crust and subsequent

snowfall which forms the instability in the snowpack. (McClung and Schaerer, 1993) However,

rain does not always weaken a snowpack. In small quantities, rain contributes little to the

transfer of heat at the snow surface because it requires so much energy to convert ice to water;

large quantities of warm rain are required before melting at the snow surface occurs. (Daffern,

1999)

In mid-November 2001, warm rain fell on the high elevations of the Selkirk Mountains.

Above zero temperatures were recorded at the weather station on Mt. Fidelity, as well as rain

21

over three days at this time,(See Figure 14). After this rain event, no rain was recorded and the

next seventeen days saw only one centimeter fall (See Figure 14). Above zero temperatures

during this warm, snowless period would mean that a "temperature crust" or warm air induced

melt-freeze layer could develop. (Jamieson, 2004) As a result of no snowfall, the effect of the

temperature crust would impact the same snow surface that was affected by the rain. Once a

significant crust was established, stability was threatened by the buried crust and avalanche

hazard increased. Jamieson investigated this and found "Crusts are usually stiffer and harder

than the overlying snow, they concentrate shear stress within the sloping snowpack and hence

can contribute to shear failure at the upper boundary of the crust." (Jamieson, 2004). The thick

November crust remained until sufficient snowfall on top of it caused it to begin failing at the

beginning of January when it was reported that widespread avalanche activity was occurring in

the Selkirk Mountains between January 2nd and 19th, 2003. (See Figure 15) (BC Coroners

Service). The layer mentioned above continued to fail through the month of January and in two

separate avalanche episodes on January 20th and February 1st, fourteen skiers and snowboarders

were killed.

January 20, 2003-Durrand Glacier Avalanche

On January 20, 2003 a particularly devastating avalanche occurred involving two groups

of ten and eleven experienced skiers and snowboarders from the United States were caught in an

avalanche on Durrand Glacier on Tumbledown Mountain. The groups were travelling with the

Selkirk Mountain Experience led by an Association of Canadian Mountain Guides certified

guide. The guide changed the plan to tour up La Taviata couloir instead of up to Fronlap peak.

The couloir was wind-loaded which could have increased the weight of snow above any weak

snowpack layers. The two groups were ascending the La Traviata couloir on a switchback track

22

when the first grouped reached a convex roll and triggered an avalanche that was 50m wide

400m long and 50cm deep. The primary avalanche triggered two smaller avalanches. Thirteen

skiers were caught in the avalanche in all and seven died. At least one of the survivors was

completely buried and found under 280cm of snow. (Penniman and Bauman, 2003).

The topography of the point of failure in this avalanche was a convex feature, which for

reasons discussed earlier can be significant. In this scenario the convex roll was most likely the

critical factor in the avalanche sliding on the November rain crust.

February 1 2003-Balu Pass

Twelve days following the Durrand Glacier avalanche, a seventeen person school group

from Calgary, Alberta were ski touring up on the Balu Pass trail when a natural avalanche

released above the group on Cheops Mountain. The avalanche had enough momentum to turn at

the bottom of the track and continue down the Connaught Creek drainage where it met and

buried all seventeen skiers. Two skiers in another group witnessed the avalanche and skied down

and rescued one of the supervisors of the group whose hand had been visible through the debris.

The supervisor then contacted park wardens who were on the scene in forty minutes. At that time

some of the students that had been rescued by the guides were already digging for the others.

Seven of the students were killed and of the remaining ten remaining members of the party only

a few sustained minor injuries. (Alpine Club of Canada, 2005)

The Balu Pass Avalanche was not human triggered (Alpine Club of Canada, 2005). It is

therefore difficult to determine what precautions could have been taken place to avoid the

accident other than simply not choosing to tour in the Balu Pass region that day. The avalanche

rating was 'considerable' (Alpine Club of Canada, 2005) but may have been improperly assessed

if this magnitude of avalanche occurred naturally. The coroners report insists "the group chose a

23

location to ski which was considered one of the lowest risk areas in the park. In spite of that

preparation, tragedy struck." (BC Coroners Service 2) This account infers the tragedy was

unavoidable and unfortunate. In any case, this avalanche was the second major avalanche in the

region over a two week period that killed a total of 14 people. It can therefore be assumed the

November rain crust should have been taken more seriously and must similar layers in the

snowpack in coming years should be evaluated carefully when assessing avalanche hazards.

The November rain crust layer in the snowpack that caused both tragic 2003 avalanches

was gradually loaded by snow subsequent to its formation in late November. While there was

widespread avalanche activity from January 2nd to January 19th (BC Coroners Service 2), until

January 20th there were no fatal avalanches in the Selkirk Mountains. The Durrand Glacier

avalanche occurred in a snowpack that had grown from 77cm at the formation of the rain crust to

151cm at the nearby Mt. Fidelity weather station. Furthermore, the slope that failed was subject

to wind loading (Penniman and Bauman ,2003) which would have deepened the snowpack. The

Cheops - Balu Pass avalanche occurred when the snowpack had grown from 77cm at the time of

the formation of the rain crust to 211cm at the time of the avalanche. The November rain crust

failed following substantial subsequent snow accumulations in both the Mount Cheops Balu Pass

and the Durrand Glacier Avalanches.

7. Human Hazard and Park Policy

In efforts to examine how magnitude and frequency of avalanche activity poses hazards

for visitors and backcountry users to the Connaught Creek area of Glacier National Park we

compiled human data into our research to gain a comprehensive understanding of the patterns

and trends involved in avalanche accidents and human fatalities.

According to the Canadian Avalanche Centre (C.A.C.), British Columbia has had the

24

highest amount of avalanche fatalities in Canada since the earliest recorded incident in 1782.

(Campbell et al., 2007) Current trends in „self-sufficient‟ recreational activity taking place in

backcountry regions (e.g. skiing and snowmobiling) are expected to increase in future years with

growing popularity, drawing more users into the avalanche prone areas of B.C.

There is a network of increasing forces which are influencing backcountry avalanche

hazard. It is important to recognize that avalanche hazard only exists when human or property

are at risk. Both environmental and human factors, trends, and patterns are contributing to

increased avalanche risk within Glacier National Park. Environmental attributes such as terrain

and tree cover, snowpack and weather variability, and seasonal variations in these parameters

affect the frequency and magnitude of avalanches. However, patterns of human activity such as

increased visitor use and high traffic volume (See Figure 16) along the transportation corridor of

Roger‟s Pass are increasing avalanche hazard. Other social factors such as demographic trends,

knowledge and training of backcountry users, particularly with regard to decision making, will

also continue to influence the probability of accidents occurring.

Increase in Avalanche Fatalities

According to the B.C. Vital Statistics Agency, deaths from avalanches and landslides are

the highest cause of death in the natural environment by group in B.C., next to exposure to

excessive cold (Stubbings et al., 2000). While total annual fatalities from avalanches have

increased due to the influx of backcountry users(See Figure 17), per capita fatalities from

avalanches have decreased (Jamieson, 1996; Parks Canada, 2003). This drop in number of

avalanche accidents can be attributed to a number of factors. First, increased accessibility of

information on snowpack stability and an enhanced public awareness through the broadcasting of

avalanche bulletins may be increasing backcountry user knowledge and decision making

capacity. Secondly, enhancements in climate and weather technology, land-zoning processes, as

25

well improvements to safety and rescue protocol are making avalanche forecasting and rescue

more reliable and efficient (Jamieson and Geldsetzer ,1996). However, simultaneously,

recreational backcountry use continues to grow in popularity within avalanche prone areas such

as those in Glacier National Park.

Overall trends and patterns

Now more people than ever are travelling into Glacier National Park to pursue various

backcountry activities (Parks Canada, 2003). Data on winter hut use (See Figure 18), winter trail

use, as well as increases in requests for avalanche bulletins shows an overall trend in expanding

winter backcountry use. Between 1988-2002, Glacier National Park‟s winter huts were amongst

the most used out of all Canadian national parks with backcountry huts (Parks Canada, 2003).

Winter trail use in Roger‟s Pass area has also increased with over 6,000 skiers in 2003 holding

backcountry permits. (Parks Canada, 2003) The use of the avalanche bulletins in Canada is also

on the rise. This growth reflects the increasing availability of the information through various

online sources, but also reflects the upward trend of the public use in winter backcountry areas.

(Parks Canada, 2003) (See Figure 19). The amount of website visits to the Canadian Avalanche

Centre seeking information on current avalanche conditions has risen from 25,000 in the winter

of 1994–1995 to 240,000 in 1999–2000. (Jamieson and Geldsetzer ,1996) However, proof that

an increase in use of bulletins has lead to a reduction in avalanche accidents as a result has not

been distinguished (Jamieson and Geldsetzer, 1996).

Age and Gender

Fatalities from avalanches and slides occurred in every year in B.C. between 1985-1998.

1998 presented the most fatalities due to avalanches. (Stubbings. et al. 2000) (See Figure 20) The

demographic (gender and age group) with the highest number of environmental deaths between

1985-1998 are male in the 30-34 age group. (Stubbings, et. al. 2000) Other reports show that the

26

characteristics of an avalanche victim are considered to be male between the ages of 20-29 years

old (Jamieson and Geldsetzer, 1996). This demographic trend can be assumed to be true, as

young males with expendable incomes generally pursue most extreme recreational activities such

as backcountry skiing and mountaineering.

Environmental Factors

The tree line is defined as the “elevation band above the dense forests and below the area

with very few or no trees," and areas above treeline are classified alpine (Jamieson and

Geldsetzer, 1996). The alpine areas of mountain ranges are often the location of start zones of

large avalanches because the exposure of wind, precipitation, and snowpack distribution are

much higher in this region (Jamieson and Geldsetzer, 1996). The cirque on the southern aspect

of Grizzly Mountain, above the Grizzly slide path, is an example of this setting. According to

the Canadian Avalanche Association (C.A.A) there are three reasons why more avalanche

accidents occur in alpine areas:

1) Recreationalists generally prefer less densely forested areas.

2) The Snowpack is more stable in dense forests than in large open spaces between the trees.

3) Wind at and above tree line levels builds slabs in lee and cross-loaded areas, resulting in

less stable slabs which can be hard to recognize. (Jamieson. et al.1996)

Visitor and backcountry use

As Glacier National Park grows in international recognition as a hub for backcountry

activities, visitors to the park have increased in number (Parks Canada, 2003). Subsequently

increased usage is increasing the probability of the occurrence of avalanche accidents. The Balu

pass trailhead begins in the front country Land Management Unit (LMU) of the Glacier Park

transportation corridor, located within a 1km radius of the trans-Canada Highway, a hotel,

service station, nine picnic areas, two campgrounds, and discovery centre. Parks Canada states

27

in their management plan “this LMU is the busiest area in the parks” and that “visitors to the

front country experience an authentic historic setting and a Columbia Mountains wilderness.”

Balu pass is one of seven “self-guiding” trails and backcountry trailheads accessed within the

transportation corridor, making this trail extremely accessible for visitors. Parks Canada claims

that they do monitor and control some natural processes (e.g., landslides and avalanches) in the

interests of public safety as part of their management actions, however, continues to not

recognize Balu Pass as a “high use backcountry area” under their Management plan. (Parks

Canada, 2003) The trailhead of Balu Pass is located in the transportation corridor and front

country LMU, but the actual trail falls within the designated North Glacier LMU, stated as “ a

wild, rugged area with old-growth forests” where “Visitors in most parts of the unit experience

solitude, face challenges, undertake risks and must be self-reliant”. (See Figure 21)

Human Hazards and Risks of Avalanches

As previously noted, the major causal factor in avalanche accidents are humans

themselves. Recognition of hazards and risks are based on a users ability to prepare, seek out

information, and make knowledgeable and informed choices. Parks Canada defines hazard as

"the source of harm" (Parks Canada, 2003). A risk is defined as “the chance of loss or harm to

life (injury, death) and property, expressed as probability of occurrence (P) times consequence

(C) or quantitatively as R = P x C.” (Parks Canada, 2003) Failure to prepare for consequences of

backcountry travel increases the risk of encountering hazards such as an avalanche or slide.

Making use of information and resources on safety and navigation (e.g., maps, guidebooks, snow

stability, weather, experienced backcountry users) is an important step in the prevention of

avalanche accidents. Making a trip plan that includes the time, date and location of the start and

return, as well as alternate routes, is an extremely important part of the planning process, and

28

helps the success of any search and rescue process in case of emergency. Failure to bring proper

equipment and having insufficient backcountry training increases the probability and

consequences of avalanche accidents and fatalities are likely to increase. “From October 1984 to

September 1996, 75% of those that died as a result of non-commercial (recreational) avalanche

accidents were not wearing avalanche transceivers" (Jamieson and Geldsetzer, 1996).

Poor decision-making and behavior can result in a small margin of safety when selecting

terrain and touring routes. Simple patterns of behavior which can lead to an increased risk of

avalanche fatalities include: informal group formation, poor group dynamics, lack of leadership,

inability to recognize unstable snow conditions, and failure to adapt to changing conditions

(Jamieson and Geldsetzer, 1996).

In order to minimize the chances of being involved in an avalanche accident, a number

of steps must be taken to prepare for the hazards one could encounter when venturing into the

backcountry in Glacier National Park. Simple steps such as registering with the visitors centre,

obtaining access permits, checking the weather and snow pack conditions, knowing route

information, and having proper training are all necessities in having an enjoyable and safe

backcountry experience. Furthermore, these steps aid the efforts of Search and Rescue (SAR)

workers in avalanche accident scenarios.

“Visitor‟s must come to the Rogers Pass Discovery Centre to register for trips due to the

fact that most areas in the park are accessed by permit only. These permits are given out

only if there is no potential for doing avalanche control that day in that location. There

are some areas that do not require a permit because they do not affect the transportation

corridor. In this case, the public does not need to register, although we encourage them

to take out a safety registration” (Sylvia Forest, 2007).

The Rogers Pass visitor centre is the main source of information regarding park permits and

registration services. Backcountry Reports (a daily information bulletin regarding avalanche

activity, weather and snow conditions); Closed Area Entry Permits (permits to enter some

29

restricted areas on a day-by-day basis); and a Voluntary Registration Service, where visitors can

hand-in their trip plans, are ways in which the visitor and backcountry user can limit the

probability and consequences of being involved in an avalanche accident. (Parks Canada, 2006)

Weather and snow stability information is made available for most mountain regions in Western

Canada through the C.A.C‟s daily-recorded telephone service or as posted notices in the area of

trailhead, at Rogers Pass visitor‟s centre, and online. (C.A.C. 2007) Backcountry users can also

take various avalanche courses provided by C.A.A. approved instructors.

The B.C. Government also has a study of public safety education and awareness

underway with a strong emphasis on the public warning system. „Adventure Smart‟, a non-for

profit education-based program has been initiated by the BC Government as a means of public

education on avalanches. (PEP, 2007) Furthermore, the C.A.A. and a consortium of concerned

parties such Whistler/Blackcomb and the Resorts of the Canadian Rockies have sponsored

Rocky Mountain Sherpas, a video production company based out of Squamish, BC, to create

avalanche awareness and safety films targeting younger audiences who are increasingly exposed

to films showing professional skiers and snowboarders in backcountry situations. The series will

include a film targeted for large audiences as well as several short segments suitable for high

school settings.

8. Conclusion

Tree ring analysis performed in this study demonstrates that significant avalanche activity

occurs within the Grizzly Mountain avalanche path. This region is popular with backcountry

enthusiasts and research presented in this study strongly suggest that avalanches present a

significant environmental hazard to backcountry users in Glacier National Park and the broader

region of Selkirk Mountains. Further dendrochronological research is necessary to more

30

effectively develop a relationship regarding the frequency and magnitude of avalanches in

prominent locations in Glacier National Park.

The climate of Rogers Pass produces a snow pack with characteristics that occur

commonly throughout most winters. Periods of intense cold with little precipitation produce

surface hoar crystals, while even brief periods of warmer temperatures can produce a slick crust

on the snow surface. Heavy snowfalls are also common in this region of the Columbia

Mountains, and can bury a crust or surface hoar layer under a great deal of snow, creating

conditions of high avalanche hazard when, historically, fatal avalanches have occurred.

Furthermore, much research is required to continue to advance snow-science knowledge in order

to update and advance the techniques and tools used to forecast avalanche hazard.

Parks Canada should increase their collaborative work with other active avalanche

education and research bodies, such as the C.A.A and C.A.C, to increase its integrated approach

on effectively monitoring, identifying, and evaluating the potential environmental hazards of

avalanches in Glacier Park. The implementation of restrictions on backcountry use during

periods of extreme avalanche hazard may limit the number of preventable avalanche accidents.

Sharing information regarding backcountry user registration and permits between Parks Canada

and the C.A.A , C.A.C, and S.A.R will allow for improvements in the management of

backcountry use in National Parks. A review was commissioned to evaluate the success of Parks

Canada's current hazard management efforts, and to make recommendations for improvements

where necessary (Parks Canada, 2003). Parks Canada states in their review that they can

improve the „perception of the inherent risk‟ from those backcountry winter activities. (Parks

Canada, 2001). The results of this review highlight another conclusion of this study regarding

the need for an increased public awareness campaign. The avalanche awareness videos being

31

produced by Rocky Mountain Sherpas are an excellent example of an effective avalanche

education strategy for widespread use. Educational material which captivates and interests all

ages of backcountry users and successfully conveys fundamental knowledge for safely

experiencing backcountry locations in winter is the most important tool in reducing the number

of avalanche accidents which occur in mountain national parks and other regions in the Canadian

cordillera.

Winter travel in backcountry regions of mountain National Parks, such as the Connaught

Valley in Glacier National Park, has inherent risks and management issues for Parks Canada.

Understanding the relationship of avalanche magnitude and frequency in the Grizzly Mountain

avalanche path, as well as commonly occurring snowpack weaknesses in this region,

management policies may be adopted to reduce the number of avalanche accidents which occur

in Glacier National Park. Humans are the only constant in avalanche accidents, and are therefore

the most important aspect of reducing the number of avalanche accidents. Educating

backcountry users should be the primary goal of Parks Canada in order to decrease backcountry

avalanche accidents, while monitoring and restricting use should be a secondary goal in order to

limit preventable accidents and provide information for further research.

9. References:

Alpine Accidents in Canada . 2005. Alpine Club of Canada. Available Online:

http://alpineclub-edm.org/accidents/accident.asp?id=924. Date Accessed: 22-11-07.

Atlas of Canada. "Statistics on Major Avalanches.” Natural Resources Canada . Available

Online: atlas.nrcan.gc.ca:80/site/english/maps/environment/naturalhazards/nature

alhazards1999/majoravalanches/avalanches_stats_new.html. Date accessed: 11-01-07.

Avalanche Statistics: Canada 2002-2003. No Date. Cyberspace Avalanche Center. Available

Online: http://www.avalanche-center.org/Incidents/statistics/2002-03-canada.php. Date

Accessed: 24-11-07.

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Avalanche Terrain Ratings. 2007. Parks Canada Agency. Available Online:

http://www.pc.gc.ca/pn-np/inc/PM-MP/visit/visit7a1_e.pdf. Date Accessed: 22-11-07

BC Coroners Service, Judgement of Inquiry. Case No. 2003:528:0002 Police File: 2003-0158

Police Department: Revelstoke RCMP, 2003

BC Coroners Service 2. January 28, 2004 Quoted in: Avalanche victim's father calls

coroner's report 'irrelevant'. Available Online: www.cbc.ca/. Date Accessed: 22-11-07

Birkeland, K. 1998, Terminology and Predominant Processes Associated with the Formation of

Weak Layers of Near-Surface Faceted Crystals in the Mountain Snowpack. Arctic and

Alpine Research. Vol 30, No.2: pp. 193-199.

Birkeland, K., Johnson, R., and D. Schmidt. 1998. Near-Surface Faceted Crystals Formed by

Diurnal Recrystallization: A Case Study of Weak Layer Formation in the Mountain

Snowpack and Its Contribution to Snow Avalanches. Arctic and Alpine Research. Vol

30, No.2: pp. 200-204.

Campbell, C et al. 2007. Current and Future Snow avalanche threats and mitigation measures in

Canada. Prepared for Public Safety Canada by C.A.C. Pgs 18-19.

Canadian Avalanche Association (C.A.A) . 2007. Revelstoke, B.C. Available Online:

www.avalanche.ca. Date accessed: 11-01-07

Chalmers, T. and B. Jamieson. 2003. Forecasting shear strength and skier-triggered avalanches

for buried surface hoar layers. Extended abstract in Proceedings of 2002 International

Snow Science Workshop in Penticton, Canada, (J.R Stevens, editor). BC Ministry of

Transportation, Victoria, BC, 138-140.

Chalmers, T. and B. Jamieson. 2001. Extrapolating the Skier Stability of Buried Surface Hoar

Layers from Study Plot Measurements. Cold Regions Science and Technology. Vol. 33,

No. 2-3: pp. 163-177.

Daffern, Tony. 1999. Avalanche Safety for Skiers, Climbers and Snowboarders. Rocky

Mountain Books: Calgary, Alberta.

Deems, J.S., 2002. Topographic Effects on the Spatial and Temporal Patterns of Snow

Temperature Gradients in a Mountain Snowpack. M. of Sci., Montana State University.

Environment Canada. 2007. National Climate Data and Information Archive- Roger's Pass,

Mount Fidelity Station. Available Online:

http://www.climate.weatheroffice.ec.gc.ca/climateData/dailydata_e.html?timeframe=2&

Prov=CA&StationID=1345&Year=1988&Month=1&Day=27

Environmental Deaths, 1985 to 1998. 2000. BC Vital Stats Agency. Quarterly Digest, Vol. 9

No. 4.

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Hägeli, P. and McClung D.M., 2003, Avalanche Characteristics of a Transitional Snow Climate -

Columbia Mountains, British Columbia, Canada. Cold Regions Science and Technology,

37(3), 255-276

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Alberta, Canada. Artic and Alpine Research. Vol. 15, No. 2: pp. 271-274.

Jamieson, Bruce. 2000. Backcountry Avalanche Awareness. 7th edition. Canadian Avalanche

Association: Revelstoke, B.C.

Jamieson, B. and Stethem, C. 2002. Snow Avalanche Hazards and Management in Canada:

Challenges and Progress.” Natural Hazards 26: 35–53.

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Crusts in the Columbia Mountains, Avalanche News 70: pp.48-54, Canadian Avalanche

Association, Revelstoke, BC.

Jamieson, Bruce. 2004. Between a slab and a hard layer: Part 2 - The persistence of poorly

bonded crusts in the Columbia Mountains. Avalanche News 71, 34-37. Canadian

Avalanche Association, Revelstoke, BC.

Jamieson, Bruce and Torsten Geldsetzer. 1996. Avalanche Accidents in Canada, Volume 4:

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Online: http://avalancheinfo.net/Newsletters%20and%20Articles/Articles/AvalancheAcci

dentsV4.pdf

McClung D.M. and Schaerer, P.A. 1993, The Avalanche Handbook. The Mountaineers, Seattle,

WA, USA

Parks Canada. 2001. Mount Revelstoke National Park of Canada and Glacier National Park of

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independent panel).

Parks Canada. 2005. Mount Revelstoke National Park and Glacier National Park of Canada and

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Parks Canada. 2006. Rogers Pass Centre: Permits and Information – Activities: Ski Touring in

Rogers Pass, Glacier National Park of Canada. 2006. Accessed Online:

http://www.pc.gc.ca/pn-np/bc/glacier/activ/activ1_E.asp. Date accessed: 11-27-07

Penniman, D. and Baumann, F. 2003. The SME Avalanche Tragedy of January 20, 2003: A

Summary of the Data. Snowbridge Associates: Truckee, CA, USA

Provincial Emergency Program. „Adventure Smart‟. Available online : www.adventuresmart.ca.

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Columbia. In: Mountain Geomorphology: Geomorphological Process in the Canadian

34

Cordillera. Edited by: Slaymaker, O.; and McPherson, J.J. Tantalus Research Ltd:

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Stethem, C.J. and P.A. Schaerer. 1979. Avalanche Accidents in Canada I, A Selection of Case

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Stethem, C.J. and P.A. Schaerer. 1980. Avalanche Accidents in Canada II, A Selection of Case

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Sylvia Forest. Alpine Specialist, IFMGA Mt. Revelstoke and Glacier National Parks. Email

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British Columbia Ministry of Forests, Victoria, B.C., Canada.

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35

Appendix

Figure 1. Rogers Pass and Glacier National Park. (Source: Parks Canada)

36

Figure 2- Overview of Connaught Drainage Basin from Balu Pass.

(Photo: Courtesy of Jim Gardner)

37

Figure 3. Figure 4.

Figures 3 and 4- Grizzly Slide path, Connaught Drainage Basin (site of field work). Grizzly Peak is located at the top of figure 3.

(Photos Courtesy of Jim Gardner)

38

Figure 5- Mountain Peaks of Rogers Pass during winter months. The TransCanada highway is at the base of the figure,

while the Balu Pass trail network is located in the valley beneath "Grizzly Shoulder."

(Courtesy: www.leelau.net/2005/rogerspass/grizzly/grizzlyshoulder.htm)

39

Figure 6- Connaught Creek Drainage Basin. (Area map produced by: Ben Ferrel)

40

Figure 7. Common Backcountry ski touring routes in the Connaught Drainage basin and associated avalanche hazard. (Area

map produced by: Ben Ferrel)

41

Figure 8.

42

Fig 9: Transect of east side of path, day 1, with observed age classes.

43

Figure 10.

44

-30-28-26-24-22-20-18-16-14-12-10-8-6-4-202468101214161820222426283032343638404244464850

-30-28-26-24-22-20-18-16-14-12-10

-8-6-4-202468

101214161820222426283032343638404244464850

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

Tem

pe

ratu

re (

de

gre

es

C)

Dai

ly S

no

wfa

ll (c

m)

Day of Month (January)

Figure 11. Daily Temperature and Snowfall at Mt. Fidelity, Roger's Pass-January, 1988 (Steadfast Creek Avalanche)

Total Snow cm

Max Temp °C

Min Temp °CStandfast Creek Avalanche

Clear, Cold Weather Condiitions

Heavy Snowfall

45

-15-14-13-12-11-10-9-8-7-6-5-4-3-2-1012345678910111213141516171819202122232425

-15-14-13-12-11-10

-9-8-7-6-5-4-3-2-10123456789

10111213141516171819202122232425

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

Tem

pe

ratu

re (

de

gre

es

C)

Sno

wfa

ll (c

m)

and

Rai

nfa

ll (m

m)

Day of Month (March)

Figure 12. Daily Temperature and Snowfall at Mount Fidelity, Roger's Pass-March, 1988 (Sale Mountain Avalanche)

Total Snow cm

Total Rain cm

Max Temp °C

Min Temp °C

Sale MountainAvalanche

Clear, cold weatherfollowed by warm spell

Heavy Snowfall

46

-20-18-16-14-12-10-8-6-4-20246810121416182022242628303234363840

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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

Tem

pe

ratu

re (

de

gre

es

C)

Sno

wfa

ll (c

m)

Day of Month (March)

Figure 13. Daily Temperature and Snowfall at Mount Fidelity, Roger's Pass -March 1993 (Bruins Pass Avalanche)

Total Snow

Max Temp oCMin Temp oC

Bruin Pass Avalanche

Cold snow falls on warm snow

Cold spell-cools suface snow

Heavy Snowfall

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wfa

ll (c

m)

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nfa

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m)

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p (

oC

)Figure 14. Daily Temperature and Snowfall at Mt. Fidelity,

Roger's Pass-November 2002

Rainfall (mm)

Snowfall (cm)

Max Temp (oC)

Rain during warm spellforms rain crust

Snowless period of warm temperatures

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0

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250

-20

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Sno

wfa

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Tem

p (

oC

)Figure 15. Daily Temperature and Snowfall at Mt. Fidelity,

Roger's Pass-December 2002/January 2003

Snowpack (cm)Snowfall (cm)

Max Temp (oC)

Sno

wp

ack

(cm

)

Balu Pass Avalanche

Durrand Glacier Avalanche

'WidespreadAvalanche Activity in Northern Selkirks'(BC Coroners)

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Figure 16- Trans-Canada Highway Vehicular Traffic through Glacier National Park, 1960 – 2001.

(Source: Parks Canada. 2001)

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Figure 17- Avalanche accidents in Canada (1984-1996). “ Number of Avalanche fatalities per avalanche year in Canada (Columns)

and the five year running average (dashed line). Total number of fatalities for the period is 220. (Source: Jamieson et al. Fig.2.1. Pg.8.

1996)

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Figure 20- Num 4 deaths. (Source:

Stubbings. et al. 2000)

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Figure 21- Map of North Glacier (LMU). (Source: Parks Canada. 2001)