Periglacial Landforms Flashcards
Patterned grounds
Frost heave and ice lenses pull rocks up to the surface, this then forms 2 landforms, stone polygons if it is on a slope less than 6° or stone stripes if it is more than 6°
Ice wedges
Forms due to a gap in the permafrost, creating water in the soil which can freeze and widen the gap due to freeze thaw
Pingos
Freezing water in the upper layers of discontinuous permafrost causes sediment to rise and create a dome shape. This is an open pingo
In low lying areas of permafrost a closed pingo forms. If a small lake is present, ground water can be trapped by the permafrost below and in the lake above. the ground water freezes and expands
Blockfields
Freeze thaw weathering creating large angular rocks
Solifluction
Downslope movement of rocks and soil due to gravity acting on the active layer in summer, this melts in spring and slumps.