T r HOW-TO/WINTER BACKCOUNTRY $19.95 U.S. e m p e r S “No one who plays in mountain snow T should leave home without having A studied this book.” Y —Rocky Mountain News I N G STAYING ALIVE IN AVALANCHE TERRAIN offers technical skills, practical advice, and A common sense approaches to dealing with avalanches. Author Bruce Tremper provides L the latest avalanche knowledge, practice, I V and the system of techniques, procedures, checklists, and protocols the pros use to E keep themselves and others alive in dangerous terrain. All outdoor enthusiasts will enjoy Tremper’s down-to-earth voice. More than 80 photos and 100 I illustrations make the information easy to understand and to put into practice. N The more tricks you know, the more knowledge about snow stability you A possess, the better your travel skills and rescue skills, and most important, the V more mastery you have over your own human foibles, the better your odds for A surviving in avalanche terrain. In this book, Tremper gives you everything you need, including: L A • Recognizing safe terrain vs. dangerous terrain • Tests for judging snow stability N • Safe travel techniques C • What to do if you’re caught in an avalanche • Search and rescue strategies H • Managing the human factors that cause avalanche accidents E BRUCE TREMPER is the director of the Forest Service Utah Avalanche Center T second edition and coordinated backcountry avalanche safety preparations for the 2002 E Olympic Winter Games in Salt Lake City. He is one of the nation’s foremost R STAYING ALIVE experts on avalanches, and has appeared in news reports and documentaries R produced by National Geographic, PBS, and Discovery Channel, among others. A IN AVALANCHE TERRAIN I N Bruce Tremper 978-1-59485-084-4 Property of Max Pankov, [email protected] STAYING ALIVE in AvAlAnche TerrAin Property of Max Pankov, [email protected] Property of Max Pankov, [email protected] second edition STAYING ALIVE in AvAlAnche TerrAin Bruce Tremper Property of Max Pankov, [email protected] To Bill and Barbara Tremper v The Mountaineers Books is the nonprofit publishing arm of The Mountaineers Club, an organization founded in 1906 and dedicated to the exploration, preservation, and enjoyment of outdoor and wilderness areas. 1001 SW Klickitat Way, Suite 201, Seattle, WA 98134 © 2008 by Bruce Tremper All rights reserved. First edition, 2001. Second edition, 2008. no part of this book may be reproduced in any form, or by any e lectronic, mechanical, or other means, without permission in writing from the publisher. Published simultaneously in Great Britain by Bâton Wicks, London Distributed by Cordee, 3a DeMontfort Street, Leicester LE1 7HD Manufactured in the United States of America copy editor: erin Moore illustrations: Gray Mouse Graphics this is what the eps file looks like...all this within one file...you can see the crop marks I refer cover, book design, and layout: Peggy egerdahl to in the explanation. All photos by the author unless otherwise noted Ani cover photograph: Andrea Binning releases a slab avalanche on her second turn from the ridge top of the Coast Mountain Range near Mount Waddington, BC. © Mark Gallup.com Frontispiece: Snowbird avalanche expert Dean Cardinale with his avalanche search dog, Midas, on a search for two backcountry snowshoers who were killed in an avalanche they triggered. Neither snowshoer wore a beacon; the only way to locate them was with ava- lanche dogs and probes. (Wasatch Range, Utah) Back cover photo: Author doing field work Library in Congress Cataloging-in-Publication Data Tremper, Bruce, 1953- Staying alive in avalanche terrain : how the pros keep themselves and others alive / by Bruce Tremper.—2nd ed. p. cm. includes bibliographical references and index. 1. Mountaineering—Safety measures. 2. Avalanches—Safety measures. i. Title. Gv200.18.T74 2008 796.9028'9—dc22 2008027104 Printed on recycled paper Property of Max Pankov, [email protected] CoNTENTS Acknowledgments ____ 6 Introduction ____ 8 chapter one AvAlAnche BAsics ____ 25 chapter two how AvAlAnches work ____ 39 chapter three TerrAin MAnAgeMenT ____ 67 chapter four weATher ____ 97 chapter five snowpAck ____ 113 chapter six sTABiliTy ____ 148 chapter seven hAzArd evAluATion ____ 205 chapter eight rouTefinding And sAfe TrAvel riTuAls ____ 222 chapter nine rescue ____ 245 chapter ten The huMAn fAcTor ____ 279 Appendix: United States Avalanche Danger Descriptors ____ 303 Glossary ____ 304 Bibliography ____ 309 Index ____ 312 Property of Max Pankov, [email protected] ACkNowLEdGmENTS if you like this book, please don’t thank me; i’m just the messenger. Most of the ideas in this book came from the pioneers of avalanche research and education, which started in the United States with ed lachapelle, Monty Atwater, and ron Perla, who ran the Alta Study center from just after World War ii to1972. Together, they came up with the bulk of what we now teach in modern avalanche schools, as well as most of the techniques now used in avalanche forecasting, control, and rescue. As you will notice, the names of my mentors, Doug Fesler and Jill Fredston, come up repeatedly in this book, and for good reason. Doug Fesler has lived among the big Alaska avalanches for 40 years. he started the Alaska Avalanche School in the early 1970s; he was joined by Jill Fredston, now his wife, in the early 1980s. Together they now run the Alaska Mountain Safety center. As near as i can tell, they know more about avalanches and more about teaching avalanches than anyone else in the world. Most of the organization and pre- sentation of avalanche concepts in this book were pioneered and refined by Doug and Jill through hundreds of multiday avalanche courses. Special thanks for the hard work of the manuscript review committee: Dale Atkins colorado Avalanche information center roger Atkins canadian Mountain holidays helicopter ski guide Karl Birkeland Forest Service national Avalanche center Doug coombs pioneer of the valdez, Alaska, extreme skiing phenomenon Doug Fesler Alaska Mountain Safety center liam Fitzgerald Utah Department of Transportation avalanche forecaster Bruce Jamieson avalanche researcher, University of calgary, canada ron Johnson Gallatin national Forest Avalanche center Tom Kimbrough Forest Service Utah Avalanche center ed lachapelle America’s most venerable avalanche expert evelyn lees Forest Service Utah Avalanche center ian Mccammon engineering consultant and national Outdoor leadership School avalanche instructor Mark Moore northwest Weather and Avalanche center Mark newcomb helicopter ski guide and world-class mountaineer Peter Schaerer canada’s most venerable avalanche expert Juerg Schweizer Swiss Federal institute of Snow and Avalanche research Knox Williams colorado Avalanche information center 6 Property of Max Pankov, [email protected] AcKnOWleDGMenTS 7 Thanks also go out to the many people who have made significant contributions to this book but, for various reasons, were not able to review the manuscript. Those include (in alpha- betical order): ed Adams, Duain Bowles, Bob Brown, howard conway, rand Decker, Kelly elder, Jill Fredston, Andy Gleason, hans Gubler, clair isrealson, Janet Kellam, nick logan, Dave Mcclung, Art Mears, John Montagne, halstead Morris, ron Perla, Doug richmond, Don Sharaff, Grant Statham, and chris Stethem. The second edition was reviewed by Karl Birkeland, ian Mccammon, and ron Johnson, and thanks to erin Moore for her wonderful editing. Property of Max Pankov, [email protected] INTroduCTIoN It’s so wonderful finding out you were wrong, that you were ignorant, that you know nothing, not squat. You get to start over. —Rick Bass whAT hAppens when you geT cAughT in An AvAlAnche? it was november 1978. i was a cocky, ex-national-circuit ski racer, 24 years old, fresh out of college, and because i needed the money i was building chairlifts at Bridger Bowl Ski Area in Montana. in the ignorance and vigor of youth, i naturally enough considered myself to be an avalanche expert. i had grown up in the mountains of western Montana where my father had taught me about avalanches when i was 10 years old, and i had skied in the backcountry the past several years and had so far avoided any serious mishaps. in other words, i was a typical avalanche victim. i was skiing alone (first mistake) and not wearing a beacon (second mistake). After all, i wasn’t “skiing,” i was “working,” tightening the bolts at the base of each chairlift tower with a torque wrench. even in my stubborn ignorance, i could see that it was clearly very danger- ous. Over a foot of light snow had fallen the night before on top of fragile depth hoar and the wind was blowing hard, loading up the steep slopes beneath the upper section of the chairlift with thick slabs of wind-drifted snow. Starting from the top, i skied down, stopping at each tower to torque the bolts. When i was finished with the tower at the top of the avalanche paths, i took off my skis and started walking back up the slope so i could gain the ridge and circle around to the tower beneath the avalanche paths. But i quickly discovered my third mistake. Since i didn’t bring my backcountry skis or climbing skins, the easy ski down was now an exhausting pig wallow back up through chest-deep snow, and the nearby snow-free cliffs were too scary to climb in my slippery plastic boots. i couldn’t help but notice that only a 15-foot-wide couloir at the base of the cliffs separated me from the safe slopes on the other side. naturally enough, i thought a good skier like me should be able to get up speed and zip across it before anything too bad happened. (Ski cutting alone and without a beacon or partner—fourth mistake.) i did my ski cut according to the book. i built up speed and crossed the slope at about a 45-degree angle so that, in theory, my momentum would carry me off the moving slab, in case it did break on me. Since i had never been caught in an avalanche before, i had no idea how quickly the slab—after it shatters like a pane of glass—can pick up speed. i heard a deep, muffled thunk as it fractured. Then it was like someone pulled the rug out from under me and i instantly flopped down onto the snow, losing all the precious speed i had built up. like a startled cow, i sat there on my butt and watched soft slab shatter into little 8 Property of Max Pankov, [email protected] inTrODUcTiOn 9 blocks and the blanket of snow rocketed down the slope as if sucked downward by extra- heavy gravity. i jumped to my feet and tried to build up my speed again so i could jet off to the side, but it was far too late. The blocks of shattered slab were moving all around me, like a herd of tumbling cardboard boxes blowing in the wind. nothing seemed to work. even though only 2 or 3 seconds had elapsed, the avalanche, with me as its unintended passenger, was already moving a good 20 miles per hour (mph). looking downhill, i saw a line of small trees coming toward me at a frightening speed. They looked like periscopes slicing through the water in an old World War ii movie. i tried to maneuver to grab one of them. But the avalanche, as i discovered, pretty much has its way with you. choice is an option you think you might have before you’re caught in an avalanche, but never afterward. luckily it took me directly into the smallest tree and i slammed it hard and held on with all my strength. The snow pounded me like i was standing under a huge waterfall, and it felt like my neck would snap as each block of wind slab smashed into my head. The tree snapped off, and i rocketed down the slope again. Then the tumbling started, over and over like being stuck in a giant washing machine filled with snow. hat and mittens, instantly gone. Snow went everywhere, down my neck, up my sleeves, down my underwear—even under my eyelids, something i would have never imagined. With every breath, i sucked in a mixture of snow and air that instantly formed a Skiers triggering an avalanche (Columbia Mountains, British Columbia) © Brad White/Alpenstock Property of Max Pankov, [email protected]