How do cracks and crevasses contribute to iceberg calving?

Cracks and crevasses are fundamental to the process of iceberg calving, as they create inherent planes of weakness within ice shelves and glaciers that eventually lead to fracturing.12

These features contribute to calving in several ways:

• Structural Weakness: Because ice shelves and glaciers naturally possess these fissures due to stress from movement, they provide the structural points where the ice will eventually break to yield freely floating icebergs.12
• Frost Wedging: In some cases, surface meltwater fills nearby crevasses. As this liquid water refreezes, it expands, producing fractures at the base of the crevasses. This process, known as frost wedging, can cause an ice shelf to splinter and disintegrate.1
• Bending Stress: Crevasses can be exacerbated by external forces, such as long-range ocean swells or tidal action, which cause the ice to oscillate and bend. This bending stress is particularly significant in glacier tongues, where it can lead to fracturing.1

Ultimately, these cracks transform a continuous, flowing mass of ice into discrete, floating structures.1