In areas subject to numerous diurnal cycles of freeze – thaw, water repeatedly freezing in fractures and small cracks in rocks contributes significantly to rock breakage by freeze – thaw weathering, sometimes referred to as frost weathering, or ice wedging, When water freezes, it expands in volume up to 9%, and this can cause large pressures to be exerted on the walls and bottom of the crack, widening it and eventually leading to a piece of rock breaking off.