Reading the Signs: Avalanche Risk and Decision-Making with Ian McCammon
The Avalanche Hour Podcast
Closing Reflections on Avalanche Awareness and Learning
In this chapter, the host summarizes the important insights shared during the discussion, stressing the need for a fresh perspective on avalanche slopes. The chapter also acknowledges the guest's impactful teachings and encourages audience interaction with the show's creative resources.
Ian McCammon, often considered the godfather of human factors in avalanche education, has a unique background with a foot in scientific research and another in backcountry exploration. With formal training in physics, materials science, and engineering, Ian started in R&D before becoming deeply involved in avalanche education in the 1990s. Following the loss of his friend Steve Carruthers in an avalanche, he was driven to study how experienced individuals make fatal decisions despite knowing better. His work has since shaped modern avalanche education and risk management strategies.
Ian developed the FACETS acronym:
Familiarity: We feel safer in places we've been before, even when conditions change.
Acceptance: The desire to fit in can push individuals to take unnecessary risks.
Commitment/Consistency: The drive to follow through on a plan despite new information.
Expert Halo: Over-reliance on an individual perceived as an expert.
Tracks/Scarcity: The fear of missing out on first tracks can cloud judgment.
Social Proof: Seeing others on a slope can create a false sense of security.
His research suggests that merely teaching these factors isn’t enough to change behavior—awareness must be coupled with tools for self-evaluation.
PDFs help individuals identify their personal biases and recurring decision-making flaws. By reflecting on past experiences and recognizing patterns in our own choices, we can slow down and make more objective decisions in the field.
Ian also created ALPTRUTh, an easy-to-remember checklist that has been proven effective in evaluating avalanche risk. More than 90% of avalanche accidents occur when three or more of these factors are present:
A: Avalanches in the past 48 hours.
L: Recent loading from snow, wind, or rain.
P: Obvious avalanche path present.
T: Terrain trap below.
R: Avalanche danger rating of "considerable" or higher.
U: Signs of unstable snow (cracking, collapsing, whoomping).
TH: Thawing or rapid warming conditions.
McCammon introduced the Stability Wheel, a simplified model explaining the three conditions necessary for an avalanche:
Strength: The ability of the snowpack to resist force.
Structure: Weak layers and slab formations.
Energy Release: The capacity for a fracture to propagate.
Ian explains how propagation propensity, friction, and fracture toughness are now being studied in more depth to improve predictive tools like the Extended Column Test (ECT) and Propagation Saw Test (PST).
One of Ian’s strongest messages in the episode is the importance of margins—the space we create between ourselves and dangerous terrain to account for uncertainty. He emphasizes that uncertainty is often underestimated and that decision-makers must continually assess whether they are acting on knowledge or assumptions.
Ian discusses a study that found significant human and device error in slope angle measurements, with a margin of error between 3-6 degrees. This has implications for decision-making, especially when relying on digital elevation models and inclinometer apps.
Ian highlights the need for new research in decision-making tools, material-based snowpack models, and practical field applications of computational advancements. He also discusses the role of technology in avalanche education, including digital versions of his Snow & Avalanche Fieldbook and new methods for risk communication.
“Every time you get on a slope, you have to look at it as if you're seeing it for the first time.” – Ian McCammon
• Host: Jake Hutchinson
• Guest: Ian McCammon
• Producer: Cameron Griffin
• Wyssen:www.wyssen.com
• OpenSnow:www.opensnow.com
• Gordini:www.gordini.com
• Arva:https://us.arva-equipment.com/
Music by Ketsa• Campfire
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