Periglacial Landforms Flashcards
patterned ground
description: surface material distributed in a pattern
how: frost heave, on slope it creates stripes, on level it created circles
ice wedges
description: vertical masses of ice
how: meltwater in cracks in ground & freeze thaw makes the cracks bigger seasonally
open pingo
how: found in areas of discontinuous permafrost,
surface is frozen and water is trapped beneath,
water under pressure and moves towards surface
this creates an ice core
as ice melts, pingo collapses
closed pingo
how: found in areas of continuous permafrost,
unfrozen ground beneath absorbs water
permafrost advances creating an ice mound whish continues to grow
block fields
caused by freeze thaw,
angular rocks left strewn across level ground
teracettes
small ridges in ground underneath vegetation,
formed when active layer thaws and gravity allows material to slump underneath vegetation
solifluction lobes
when saturated active layer of soil is thawed,
material flows downhill
(process) frost heave
ground freezes & pushes material upward creating indentations on ground
unfrozen ground deep beneath containing water is drawn upward
ice lenses in permafrost are pushed upward
(process) frost creep
the slow downslope movement of soil & sediment
because of frost heave & thawing
(process) rockfalls
frost shattering loosens material on steep rock faces and it falls under the force of gravity
(process) solifluction
fine grain soil moves down an incline due to gravity
(process) gelifluction
process of constant freeze thaw of active layer
