The extension and thinning of a glacier, often marked by an ice fall. Extending flow occurs near the equilibrium line, and where the velocity of the glacier increases, for example, down a rock step. Extending flow can transmit material from the surface of a glacier to its base, thus increasing its powers of abrasion. It is also responsible for crevasses and is typical of the zone of accumulation of ice. King (1970) Geografiska A 52, 3–4 notes that, in zones of extending flow, ice reaches the bed tangentially, diminishing the ice’s erosive capacity, and thus diminishing erosion.