Analysis of the Durrand Glacier Avalanche Accident

More documents

Recommendations

Info

A. Introduction Analysis of the Durrand Glacier Avalanche Accident 1. On January 20, 2003, seven ski tourers, under the leadership of Mr. Ruedi Beglinger, a Swiss-trained mountain guide, owner and chief guide of Selkirk Mountain Experience, Ltd. and member of the Association of Canadian Mountain Guides (ACMG) and the Canadian Avalanche Association (CAA), died when they were buried by an avalanche in the Durrand Glacier area, 35 km north northeast of Revelstoke, B.C., Canada. 0 100 km Vancouver DURRAND GLACIER Revelstoke Fig. 2: Location of the accident site near Revelstoke, British Columbia, Canada. 2. The victims were part of a group of 21 skiers that had departed that morning from the Durrand Chalet, a remote, helicopter-accessed mountain lodge located at the headwaters of Cairns Creek, on the west side of the Selkirk Mountains, and owned by Ruedi Beglinger’s company, Selkirk Mountain Experience Limited. B. Public avalanche bulletin and other warnings of avalanche hazard 1. For the day of the accident, the Canadian Avalanche Association’s Public Avalanche Bulletin (PAB) for the North Columbia Mountains (which includes the Durrand Glacier area) was warning that a deep seated instability was present in the snowpack, and that natural avalanches were possible, and skier-triggered avalanches were probable. Overall the hazard in the mountains was rated as being “Considerable”, which is the mid-point of the five class hazard scale. Copyright: no part of this report may be reproduced without the written permission of the author.
Durrand Avalanche Report page 2 Danger Level Probability and Trigger Recommended Action Low Moderate Considerable High Extreme Natural avalanches very unlikely. Human triggered avalanches unlikely. Natural avalanches unlikely. Human triggered avalanches possible. Natural avalanches possible, human triggered avalanches probable. Natural and human triggered avalanches likely. Widespread natural or human triggered avalanches certain. Travel is generally safe. Normal caution advised. Use caution in steeper terrain on certain aspects. Be increasingly cautious in steeper terrain. Travel in avalanche terrain is not recommended. Travel in avalanche terrain should be avoided and confined to low angle terrain, well away from avalanche path runouts. Fig. 3: Canadian avalanche hazard classification system. Key phrases are highlighted. 2. The Bulletin for January 17 to January 20 th provided the following additional information; key phrases have been highlighted. NORTH COLUMBIA REGION WEATHER: The strong ridge of high pressure over the south coast and interior BC will persist through Friday and Saturday, bringing mainly clear skies in the alpine and extensive valley fog. The ridge will begin to give way on Sunday. Expect cooler temperatures in the valley and temperatures above freezing in the alpine. Winds will be light to moderate from the NW throughout the weekend. SNOWPACK: The 15-30 cm of new snow that fell early in the week continues to settle and bond to the previous surfaces. This new snow has formed windslab in exposed areas. Moderate to hard shears are still occurring on two surface hoar layers down 70 and 100 cm. Watch for cornices failing with forecasted warm temperatures, particularly as they can be a trigger for a deep instability, which we certainly have this year. AVALANCHES: Several size 1 to 1.5 natural and human triggered avalanches, at treeline and in the alpine, were reported as recent as Wednesday. These occurrences are now becoming isolated as the recent storm snow continues to bond. A few remotely triggered size 2.5 avalanches failed in the Eastern Selkirks, some triggered from over 100 metres away. Widespread whumpfing continues to be observed in all areas. FORECAST OF AVALANCHE DANGER UP TO MONDAY EVENING (JANUARY 20 th ) ALPINE – Considerable TREELINE – Considerable BELOW TREELINE – Moderate TRAVEL ADVISORY: It is important to remember that this El Nino year is producing a complex and unusual snowpack for the mountains of BC. We have two deeply buried problem layers that are slow to heal and need our continued attention. Be alert for remote triggering and continue to be vigilant about avoiding those tempting big steep alpine faces. Any avalanche triggered on the older weaknesses may propagate extensively into a large and dangerous avalanche event. Be aware of how stresses penetrate deeper into the snowpack as you group up. Copyright: no part of this report may be reproduced without the written permission of the author.
Page 1 and 2: Analysis of the Durrand Glacier Ava
Page 3 and 4: Executive Summary page 2 The destin
Page 5 and 6: Executive Summary page 4 (e) There
Page 7: Table of Contents page 2 Figure 14
Page 11 and 12: Durrand Avalanche Report page 4 6.
Page 15 and 16: Durrand Avalanche Report page 8 G.
Page 21 and 22: Durrand Avalanche Report page 14 K.
Page 27 and 28: Durrand Avalanche Report page 20 10
Page 29 and 30: Durrand Avalanche Report page 22 (h
Page 33 and 34: Durrand Avalanche Report page 26 X.
Page 39 and 40: Durrand Avalanche Report page 32 Re
Page 41 and 42: Durrand Avalanche Report page 34 Re

Analysis of the Durrand Glacier Avalanche Accident

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?