glacier cave

Glacier caves are tunnels formed within glaciers by melting ice. Meltwater from a glacier's surface drains through crevasses, enlarging them into shafts that reach the glacier's base. This water, slightly above the melting point of ice, gradually melts the ice as it flows along the glacier's bottom.1

These caves can extend for several kilometers and often feature tubular conduits with intricately sculpted walls, sometimes forming branching patterns. The floors are typically composed of rock. Glacier caves are usually only safe to explore when the glacier's surface is frozen, as they can be filled with water at other times.1

While distinct from underground caves with permanent ice deposits, glacier caves are a type of ice cave formed by meltwater carving through ice.2