1. See ridge. 2. A ridge of ice, up to 35 m (100 ft) high and sometimes several kilometers long, in pressure ice.
Elongated uplift of the congealing crust of a lava flow believed to be caused by the pressure of the underlying, still flowing, lava.
A buckled area on the surface of a lava flow that forms because of pressure on the partly solid crust of a moving flow.