Daffern - Backcountry avalanche safety: a guide to managing avalanche risk

Contents

Copyright 2017 by Tony Daffern

Fourth Edition

Sections of this book may be made available for educational purposes or for the promotion of public avalanche safety, providing the publisher is consulted, the work is properly cited and the author is clearly acknowledged. Commercial distribution or sale of modified or derivative versions of this work in any format is prohibited without the explicit permission of the publisher.

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Cataloguing data available from Library and Archives Canada

ISBN 9781771602358 (paperback)

ISBN 9781771602365 (electronic)

Book design by Tony Daffern

All photos are by Tony Daffern unless noted otherwise.

Cover: Hard slab avalanche debris at Bow Summit in the Canadian Rockies. Photo Bob Uttl.

Distributed in Canada by Heritage Group Distribution and in the U.S. by Publishers Group West

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We acknowledge the financial support of the Government of Canada through the Canada Book Fund and the Canada Council for the Arts, and of the province of British Columbia through the British Columbia Arts Council and the Book Publishing Tax Credit.

Disclaimer

The actions described in this book may be considered inherently dangerous activities. Individuals undertake these activities at their own risk. The information put forth in this guide has been collected from a variety of sources and is not guaranteed to be completely accurate or reliable. Many conditions and some information may change owing to weather and numerous other factors beyond the control of the authors and publishers. Individual climbers and/or hikers must determine the risks, use their own judgment, and take full responsibility for their actions. Do not depend on any information found in this book for your own personal safety. Your safety depends on your own good judgment based on your skills, education, and experience.

It is up to the users of this guidebook to acquire the necessary skills for safe experiences and to exercise caution in potentially hazardous areas. The authors and publishers of this guide accept no responsibility for your actions or the results that occur from anothers actions, choices, or judgments. If you have any doubt as to your safety or your ability to attempt anything described in this guidebook, do not attempt it.

We should condemn men for crossing snow slopes in a condition favourable to avalanches, as we should condemn them for indulging in a cruise in an unseaworthy ship.

Leslie Stephen, 1865

Foreword

In this book I stress the avoidance of avalanche hazard by good routefinding, by recognition and avoidance of hazardous slopes and by staying out of avalanche terrain during periods when avalanche hazard is high.

However, I recognize that days when the snow is stable usually outnumber days when it is unstable, and that there are skiers and snowboarders who want some guidance on riding safely in avalanche terrain. I therefore try to address the difficult problem of evaluating snow stability for backcountry powder seekers and make some recommendations on techniques to use when skiing or boarding steep backcountry slopes. But the book can only point the way; you must go out into the mountains and practise what you learn here. Andr Roch, in a 1979 address to some of the worlds leaders in avalanche research, put it very succinctly when he said, Remember this, my friends, the avalanche does not know that you are an expert!

Acknowledgements

A work of this nature relies heavily on the knowledge, research and writing of others. This book is an attempt to organize and condense a vast amount of information normally available only to the snow science community or to professional mountain guides, and to interpret that information in light of my experience as a backcountry skier and climber. I have resisted the suggestion that every quote or source should be cited in referenced footnotes. There is a bibliography on for those of you who wish to read further on the subject.

However, I would like to thank several people who have made a major contribution to backcountry avalanche safety and whose work has had considerable influence on the presentation of material in this book.

Special thanks are due to Doug Fesler of Anchorage, Alaska, for permission to reproduce a major portion of his paper on choosing safe routes and making good decisions, which appears in the .

I would also like to acknowledge the contribution to backcountry avalanche safety made by Bruce Tremper and Brad Meiklejohn as a result of their addressing the issue of stability evaluation for the backcountry skier and for promoting safe skiing.

In the previous edition I neglected to mention Dale Atkins from RECCO and Bruce Edgerly from Backcountry Access, along with Manuel Genswein of Switzerland for their independent development of strategic shovelling, now considered a critical stage of backcountry avalanche rescue.

In particular I would like to recognize Grant Statham of Parks Canada for his work on the Avalanche Terrain Exposure Scale, and for his ongoing leadership in risk-based avalanche forecasting, which is the basis for Canadian avalanche forecasts.

Thanks also to Dale Gallagher for his help and encouragement, to Mrs. Martha Atwater for permission to reproduce the extract on from Monty Atwaters book The Avalanche Hunters, to Hodder & Stoughton for the quotation from Chris Boningtons Everest: South West Face, to Pete Martinelli for permission to use material from the Avalanche Handbook, and to Gord and Debbie Ritchie for their input on looking after an avalanche victim.

There were many people who assisted me in various ways. I hope the list is complete and apologize if I have missed anyone. Thanks to Dr. Eizi Akitaya, Tim Auger, Don Beers, Steve Couche, Greg Crawford, Kevin Cronin, Tom Davidson, Jim Davies, Roland Emetaz, Bruno Engler, George Field, Peter Fuhrmann, Dr. F. Furukawa, Lloyd Gallagher, Ethan Greene, Frank Grover, Kyle Hale, Clair Israelson, Bruce Jamieson, Seiiti Kinosita, Leon Kubbernus, Nick Logan, Rudolf Ludwig, Hamish MacInnes, Ian McCammon, Brad Meiklejohn, Kris Newman, Andy Nicol, Ron Perla, Andr Roche, Steve Rothfels, Tony Salway, Bob Sandford, Al Schaffer, Alf Skrastins, Peter Spear, Chris Stethem, Lars Suneby, Gery Unterasinger, Rod Ward and Knox Williams.

For this edition I co-opted guide and backcountry skier Kevin Hjertaas to cast a critical eye on the practical chapters, in particular . Thank you for your valuable input, Kevin.

Introduction

Snow avalanches are the greatest source of danger for mountain travellers in winter. They catch and very often kill the unwary who literally trigger their own destiny when they venture onto unsafe snow slopes in a moment of inattention or ignorance.