Periglacial Processes And Landforms Flashcards
Explain freeze thaw weathering
Water freezes into cracks of rocks, expanding the crack causing erosion through repeated freezing and thawing
Landforms produced by freeze thaw weathering
Accumulation of frost shattered rocks
Define solifiction
Downslope movement of the saturated active layer due to gravity
Landforms produced by solifuction
Tongue shaped gesture at foot of slope
Solifuction lobe
Define nivation
Combination of processes which weakens and erodes the ground beneath the snow patch
e.g freeze thaw, solifuction, meltwater erosion
Landforms produced by nivation
Causes hollows formed in upland areas
Define Frost heave
The freezing and expansion of soil causes the upward dislocation of material.
The freezing water pushed the stones upwards forming a dome
Landforms produced by frost heave
Large stones settling on slopes
Domes
Define ground water freezing
Water filters down into upper layers of ground then freezing.
Freezing caused the expansion of ice meaning overlying sediments heaved upwards into dome
Landforms produced by groundwater freezing
Ice core dome (pingo)
Define ground contraction
Dry areas of active layer te freeze causing contraction and cracks. Repeated thawing and freezing causes cracks to widen and deepen
Landforms produced by ground contraction
Polygonal patterns on surface
Ice wedge polygon
Define Aeolian action
Limited vegetation cover means material is easily picked up and transported fine sediment in surface
Landforms produced by aeolian action
Accumulation of deposits (loess)
Meltwater erosion
During summer thawing creates meltwater eroding streams.
Regressing in winter causes reduction in discharge and deposition