periglacial landforms

Question 1

formation of stone rings

Answer 1

patterned ground is formed through frost heave in the active layer
ice lenses exist within permafrost and grow by freezing and thawing.
capillary action causes it to grow more
when ice lenses expands,stones around ice are pushed upwards.
large stones roll down and fine sediment fill space

Question 2

formation of ice wedges

Answer 2

water falls into small cracks and expands by freezing > frost action. expanding the ground. the process repeats and leaves a big wedge

Question 3

what are the two types of pingos

Answer 3

open pingos = discontinuous permafrost
closed pingo= continuous permafrost

Question 4

formation of an open pingo

Answer 4

water moves through unfrozen ground between areas of permafrost
due to capillary action, water groups together
the water freezes to create an ice lens and then grows pushing the unfrozen ground upwards

Question 5

formation of closed pingo

Answer 5

under a lake, permafrost is insulated and melts. the lake will dry or freeze leaving unfrozen ground
ice lenses will develop through capillary action gathering it together
when temperatures drop, permafrost advances and frost heaves move the ground upwards to make a mound

Question 6

formation of terracettes

Answer 6

theoretically:
frost heave pushes particles of soil upwards, but vegetation blocks soil from falling so it stays in a step shape. creating terraces

Question 7

formation of solifluction lobes

Answer 7

when the active layer thaws and solifluction occurs, tongue shaped lobes of soil fall down a slope

Question 8

formation of blockfields

Answer 8

a rock strews landscape caused by extensive frost action of landscape

Question 9

formation of thermokarst

Answer 9

marshy boggy wetlands caused when permafrost melts.

Question 10

name all the periglacial landforms

Answer 10

patterned ground, ice wedges, pingos, terracettes, solifluction lobes, blockfields, thermokarst