Frost heaving/hillslope processes

Bedrock Heave:Pressure between TTOP and the downward advance of the active layer causes excess water pressure (saturated soils), and when there is no where for the water to go bedrock heave occurs. This heave is favored in jointed hard bedrock and chunks are shifted.Needle Ice:Ice crystals grow near the surface diurnally shifting sediment upwards, common in wet/silty/frost susceptible soil, potentially explains micro patterned ground.Cryoturbation & Frost Heave: Cryoturbation can mean the any movement due solely to frost action, OR irregular subsurface soil structures. Cryoturbation must involve water-ice state change, so frost sorting is included in the definition. Frost heaving is an annual phenomenon and can move the ground by several centimeters or more. Upfreezing is the movement of rock/sediment/material up through the active layer by either frost-pull or frost-push mechanisms. Frost-pull is understood to mean a coarser or larger particle is gripped by the advancing ice plane and lifted along with overall heave. Frost-push refers to the process of preferential freezing of soil around a pebble pushing the pebble upwards through the advancing freeze. Frost Sorting: Sorting by frost heave. Preferential fine material migration ahead of freezing plane. Mechanical sorting via gravity.

Hillslope processes and slope evolution:

French

French - 7b ch. 9