Crevasse Rescue and
Advanced Glacier Safety
The three rescue scenarios and their protocols — self-rescue prussik climbing, two-person Z-pulley haul, three-person team rescue with dedicated anchor management. Snow and ice anchor building, practice drills, terrain awareness, and what happens when conditions are complicated.
A crevasse fall is a survivable event on a properly roped team that knows what to do — and a fatal one on a team that does not. The difference between those two outcomes is almost entirely determined by what happens in the 60 seconds immediately following the fall: whether the unaffected team members arrest and anchor, whether the victim can signal their status, and whether the rescue system can be rigged and executed before the victim becomes incapacitated by cold or injury.
The rescue systems described in this guide require muscle memory under stress conditions. Reading the Z-pulley sequence does not prepare you to build it at a crevasse lip in gloves, in wind, with a partner calling from below. Take a glacier travel and crevasse rescue course (AAI, The Mountaineers, AIARE) and practise the full system with your actual rope team partners, using your actual gear, within 12 months of any objective that crosses glaciated terrain. Repeat the practice before each new objective season. This guide is a reference and framework — not a substitute for hands-on training.
Crevasse zones: quick terrain reference
Crevasses form wherever a glacier flows over a convex break in the underlying terrain — a steepening, a bend, or the transition from steep to flat ice. Understanding which zones carry the highest crevasse density allows proactive route planning that reduces exposure rather than reactive rescue after a fall.
Icefall zones
Where glacier drops steeply over a cliff or step. Ice shatters into seracs and jumbled blocks with crevasses in all orientations. Route-finding is complex and objective hazard from collapsing seracs cannot be eliminated — only timed around. Khumbu Icefall, Rainier’s upper icefalls, and Denali’s bergschrund approaches are examples.
Glacier bends and convex rolls
Tension crevasses form across the glacier perpendicular to flow direction wherever the ice bends over an obstacle. On a map, look for where the glacier changes direction or gradient significantly. On terrain, a convex roll in the glacier surface is a reliable crevasse indicator — snow bridges form over tension crevasses during winter snowfall and may be invisible in summer.
Glacier margins and edges
The sides of a glacier move more slowly than the centre, creating marginal crevasses that run roughly parallel to flow direction. These are often less predictable than cross-glacier crevasses and harder to read from the surface. Approaches that traverse across a glacier are higher-risk than those that follow the glacier centreline longitudinally.
Flat, slow-moving glacier tongues
Lower-gradient, straight glacier sections tend to have fewer crevasses but are not crevasse-free. In late season when snow bridges have melted, open crevasses are often visible from a distance and can be routed around. In early season or after new snowfall, bridges hide crevasses on even apparently flat terrain. “Lower risk” means probe aggressively and stay roped.
Bergschrund — summit headwall junction
The bergschrund is the crevasse where the moving glacier separates from the stationary ice cap or headwall. It appears as a horizontal gap at the top of a glacier, often the crux of approaches to high peaks. Crossing a bergschrund requires either bridging the gap with a snow or ice bridge or technical ice climbing to gain the headwall directly.
Snow-covered flat glacier
In winter and spring, flat glacier sections appear smooth and featureless — crevasses are completely hidden under snow. By late summer, enough snow has melted to reveal the previous year’s crevasse pattern. Always probe suspect snow (areas of slight depression, slightly different surface texture) before committing weight regardless of season.
The three rescue scenarios and their protocols
Crevasse rescue protocols are organised by team size — the number of rescuers available determines the system used. All three scenarios begin with the same first action: arrest the fall, anchor the rope, and communicate with the victim. The specific haul system then depends on how many hands are available to build and operate it.
Self-rescue is the fastest scenario when the victim is uninjured, the rope has arrested their fall within a manageable depth, and the crevasse walls are accessible for climbing. It is the preferred outcome because it requires the least from the rope team above and allows exit before cold shock sets in. The victim must initiate self-rescue within the first 5–10 minutes — after that, cold-induced grip failure and cognitive impairment from cold shock make the technique increasingly difficult.
The two-person scenario is the most common and most technically demanding rescue configuration — one person must simultaneously hold the victim’s weight, build an anchor, rig the haul system, and operate the haul. This is why it must be practised in advance. Under time pressure and with the adrenaline of a real event, the sequence must be close to automatic.
With two rescuers, roles can be split — one manages the anchor and progress-capture prussik, one hauls. This is significantly more efficient than the two-person scenario because the haul and anchor functions don’t have to be managed simultaneously by one person. A three-person rope team can execute a full Z-pulley rescue faster and with a lower error rate than a two-person team under stress.
Building anchors in snow and ice for crevasse rescue
The anchor is the load-bearing foundation of the entire rescue system. An anchor failure during a haul means both the victim and the rescuers fall into or toward the crevasse. Three anchor types are used in crevasse rescue, each appropriate for different snow conditions.
A 50–60cm aluminum picket driven at 45° away from the load direction (angled back, not vertical). In firm consolidated snow, a single well-placed picket holds crevasse rescue loads reliably. In soft snow, use two pickets in a V-configuration equalized with a sling. Drive the picket with the axe head and test by weighting with full body weight before clipping the rescue system.
A horizontal plate (aluminum deadman, Snowfluke) buried horizontally in a T-slot cut in the snow at 90° to the load direction. The plate is attached to a sling that runs through a vertical slot to the surface. Under load the plate wants to bury deeper — making it the strongest possible snow anchor. Build a T-slot by cutting a horizontal slot with the axe pick, then a vertical slot for the sling. Bury, tamp snow over, and allow 30 seconds to settle before full loading.
An ice axe buried horizontally in the snow — the same T-slot principle as the deadman plate, using an axe if no dedicated plate is available. Clip a sling to the axe shaft (not the head — the shaft is the load-bearing point in this configuration). The pick and spike end dig into the snow slot walls under load. In firm snow, a buried axe provides anchor strength comparable to a well-placed picket. In soft snow, it’s marginally weaker than a dedicated deadman plate.
How to practise before you need it: drills at the crevasse margin
Crevasse rescue skills are built in practice, not in reading. The specific drills below address each component of the rescue system separately before combining them — the same way you’d practice individual football plays before running the full game. Find a safe practice location: a gentle glacier margin, a snow slope with a self-arrest run-out, or a supervised course environment.
Special considerations: cold shock, injuries, and solo travel
The first 60 seconds in the crevasse
A crevasse fall plunges the victim into temperatures of -5 to -15°C with ice contact on all sides. Cold shock — the involuntary gasp reflex and cardiac stress of sudden cold exposure — peaks in the first 30–60 seconds. Self-rescue must begin as soon as the victim confirms they are uninjured, before cold-induced grip failure reduces prussik climbing effectiveness. If the victim cannot begin self-rescue within 3–5 minutes of the fall due to cold shock, haul rescue becomes necessary and the victim’s cooperation during lip exit will be reduced. Rescuers must factor in that a victim who was functional at the time of the fall may be significantly impaired 10 minutes later.
When the victim cannot assist
A victim with an arm injury cannot manage prussik cords. A victim with a leg injury cannot step into a foot prussik. An unconscious victim requires full haul rescue. For an unconscious or non-cooperative victim, a three-person haul is essential — two-person haul of an unresponsive victim is extremely difficult and slow. During the haul, the victim’s body must be managed at the lip — a limp victim is more likely to snag or become wedged than a conscious one. Pre-agree a signal system with the victim that they can use if they cannot call out — rope tugs remain viable even for an injured victim with one functional hand.
The honest assessment of solo glacier travel risk
Solo travel on glaciated terrain means a crevasse fall is very likely fatal. There is no self-rescue system that reliably extracts an uninjured solo climber from a crevasse without a surface attachment point above them — the prussik system requires a rope that is anchored above, which requires a rescuer or an anchor the solo climber installed before the fall. Recognised exceptions exist (ski traverses with self-arrest and detection equipment, roped solo systems) but they are complex and imperfect. For most expert objectives, the answer is simple: glacier travel requires a rope team. If the objective requires solo glacier travel, the risk assessment must explicitly acknowledge the near-impossibility of self-rescue from a full crevasse fall.
Reducing falls through route awareness
The best crevasse rescue is the one that doesn’t happen. Active route-finding on a glacier involves continuously reading snow texture, surface depressions, rope tension changes from the roped partner ahead, and the topographic context that predicts crevasse locations. When snow texture changes — harder crust to softer snow, slight dimpling on an otherwise flat surface, a subtle convex bulge — probe before stepping. The probe pole is the glacier traveller’s primary crevasse detection tool. A full team of three can leapfrog probe duties so the lead climber is never probing alone. Probing costs 10 seconds per step on suspect terrain — a crevasse fall costs significantly more.
Reading snow bridges: the hidden hazard
Snow bridges form when winter snowfall bridges across an open crevasse, creating a surface that looks identical to solid glacier snow. The bridge may be 2cm thick or 2m thick — you cannot tell from the surface. Snow bridges are strongest in cold temperatures (early morning, high altitude, early season) and weakest in warm conditions (afternoon in summer, late season, low-elevation glaciers). Understanding the visual indicators of snow bridge presence reduces — but does not eliminate — the risk.