Periglacial landforms You should be able to describe and explain the formation of various periglacial landforms including Tors Blockfields Pingos Ice.

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Periglacial landforms

You should be able to describe and explain the formation of various periglacial landforms including

• Tors• Blockfields• Pingos• Ice wedges• Patterned ground• Talus• Solifluction lobes

Patterned ground

• Ice Wedges

Describe and explain the formation of open and closed system Pingos

Periglacial landformsPatterned ground

Open system pingos

Closed system pingos

Solifluction sheets and lobes

Tors Ice wedge polygons

Nivation hollows

Talus (scree)

Blockfields

Key features (size, shape, appearance)

Processes involved

Explanation of how created

Located Example

http://www.arctic.uoguelph.ca/cpe/environments/land/land_frame.htm

Open system pingos

Large domes up to 50m high and 300m across. Circular in shape with a core of ice and surface of soil.

Freeze Thaw, Capillary actionFormation of Ice lenses

Open system pingos occur in valley bottoms where water moves to the base of the valley during the thaw season when the active layer has thawed. When temperature drops ice lenses can form in this location. Water migrates to these lenses by capillary action. On contact with the ice lenses the water freezes, swelling the size of the lense.Over time this will swell the size of the land surface to create round hills called pingos. When the pingo becomes too large cracks appear on the surface. This exposes the ice to the sun and melting occurs. The pingo collapses leaving a lake (ognip) surrounded by a ridge or rampart.

East Greenland

Locate your case studies of landforms on the map below

Name the features on the diagram

Attempt question 5 and 7 on page 139 of WaughResearch question 8