A sea ice process defined by the WMO as: The pressure process by which sea ice is forced in ridges. A ridge is a line or wall of broken ice forced up by pressure. It may be fresh or weathered. The submerged volume of broken ice under a ridge, forced downwards by pressure, is termed in ice keel. Antarctic ridges a commonly point features, whereas they are more often long and linear in the Arctic. The official IHO definition for this in the context of undersea feature names has three meanings:

an elongated narrow elevation of varying complexity having steep sides;

an elongated narrow elevation, often separating ocean basins; and

the linked major mid–oceanic mountain systems of global extent; also called mid–oceanic ridge.