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
18
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-
19
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,
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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
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Hägeli, P. and McClung D.M., 2003, Avalanche Characteristics of a Transitional Snow Climate -
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Alberta, Canada. Artic and Alpine Research. Vol. 15, No. 2: pp. 271-274.
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34
Cordillera. Edited by: Slaymaker, O.; and McPherson, J.J. Tantalus Research Ltd:
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Sylvia Forest. Alpine Specialist, IFMGA Mt. Revelstoke and Glacier National Parks. Email
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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
-20
-18
-16
-14
-12
-10
-8
-6
-4
-2
0
2
4
6
8
10
12
14
16
18
20
22
24
26
28
30
32
34
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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-15
-10
-5
0
5
10
15
20
25
30
Sno
wfa
ll (c
m)
Rai
nfa
ll (m
m)
Tem
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
48
0
50
100
150
200
250
-20
-10
0
10
20
30
40
Sno
wfa
ll (c
m)
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)
49
Figure 16- Trans-Canada Highway Vehicular Traffic through Glacier National Park, 1960 – 2001.
(Source: Parks Canada. 2001)
50
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)
51
52
53
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)