icechasms

Icechasms are deep, irregular fissures that develop within ice masses such as glaciers and ice shelves. They resemble crevasses but are distinguished by greater depth, variable width, and sometimes branching paths that can extend for hundreds of meters. Icechasms expose blue, compact ice walls and may reveal hollow voids or serac clusters within or beneath the surface. They occur in regions where ice is thick and experiences strong differential motion, including polar ice sheets and high-altitude glaciers.

They form when tensile stresses exceed ice strength, often at zones of fast flow, near outlet glaciers, or where basal melting induces weakening. Pre-existing crevasses widen; surface water can percolate and cause hydrofracturing, deepening channels. Temperature fluctuations, wind, and pressure from overlying ice contribute to crack propagation. When ice shelves calve, open fissures may extend into the shelf edge, creating icechasms that extend into the water or contact subglacial cavities.

Scientists study icechasms via satellite imagery, LiDAR, radar sounding, and in situ surveys. Their patterns help indicate glacier dynamics, thickness changes, and climate-related stress. They pose hazards to explorers and researchers, including falls, sudden collapses, and discharge of ice blocks. Safety protocols emphasize keeping a safe distance from the chasm edge and using tether lines and roped traverses in crevasse fields. Some icechasms may be temporarily bridged by overhanging ice or snow bridges, which are unstable.

In glaciology, the term icechasms is used to describe such features and is important for understanding fluid flow and mass balance in icy systems. See also crevasse, ice shelf, calving.