Glacial crevasses are not just ice cracks; they are dynamic, dangerous, and planetary phenomena

Nature · Published 3 October 2026 Swipe more like this →

In short: A crevasse is more than a simple fissure in the ice. These deep, often hidden fractures act as vital plumbing systems for glaciers, funneling meltwater to the bedrock and accelerating ice flow. From the lethal depths of Mount Everest to the crater floors of the Moon, they shape our world.

At their core, crevasses are the result of stress. When a glacier moves over a substrate, different sections of ice travel at varying speeds. This differential movement creates shear stress, causing the semi-rigid ice to fracture. Depending on the local topography, these cracks take distinct forms. Transverse crevasses, the most common variety, emerge where a valley steepens, while longitudinal crevasses appear when a glacier widens. Splaying crevasses, meanwhile, develop along the margins due to a complex interplay of shear and compressive forces.

The presence of liquid water fundamentally alters a crevasse's behavior. When water enters these cracks, it can significantly increase their penetration, sometimes reaching the very bottom of an ice sheet. This creates a direct hydrologic connection between the surface and the bed, where the water acts as a lubricant, speeding up the glacier's movement. Similar drainage occurs through moulins, vertical shafts that also channel surface meltwater deep into the glacier's interior. This process is a critical factor in understanding the mechanics of ice sheet stability.

For humans, these formations represent a significant, often lethal, hazard. Crevasses can reach depths of 45 to 50 metres, and they are frequently obscured by snow bridges—accumulated snow that hides the void beneath. These bridges can sag, but they are notoriously unreliable, making navigation across glaciers a high-stakes endeavor that requires specialized techniques like roping teams. Beyond Earth, the phenomenon is not unique to our planet; the Lunar Reconnaissance Orbiter has identified crevasse systems on the floors of lunar craters, proving that these structural fractures are a feature of planetary landscapes across the solar system.

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