how does the process of frost wedging contribute to the weathering of rock
Frost weathering The traditional explanation for frost weathering was volumetric expansion of freezing water. When water freezes to ice, its volume increases by nine percent. Under specific circumstances, this expansion is able to displace or fracture rock. At a temperature of -22 °C, ice growth is known to be able to generate pressures of up to 207MPa, more than enough to fracture any rock.[6][7] For frost weathering to occur by volumetric expansion, the rock must have almost no air that can be compressed to compensate for the expansion of ice, which means it has to be water-saturated and frozen quickly from all sides so that the water does not migrate away and the pressure is exerted on the rock.[6] These conditions are considered unusual,[6] restricting it to a process of importance within a few centimeters of a rock's surface and on larger existing water-filled joints in a process called ice wedging.
Chinook wind A strong föhn wind can make snow one foot (30 cm) deep almost vanish in one day[citation needed]. The snow partly melts and partly evaporates in the dry wind. Chinook winds have been observed to raise winter temperature, often from below −20 °C (−4 °F) to as high as 10–20 °C (50–68 °F) for a few hours or days, then temperatures plummet to their base levels. The greatest recorded temperature change in 24 hours was caused by Chinook winds on 15 January 1972, in Loma, Montana; the temperature rose from −48 to +9 °C (−54 to +49 °F).[3]