Glaciation Geography

Question 1

Scree

Answer 1

Happens on steep gradient areas due to frost shattering. Due to gravity, scree gathers at the bottom of a hill.

Question 2

Nunatak

Answer 2

Exposed summit of a ridge that is not covered by snow
They are located within an ice field or a glacier eg Suliven In Scotish Highlands
They undergo heavy frost shattering due to proximity to the ice

Question 3

Felsenmeer/blockfield

Answer 3

Exposed surfaces that have been quickly broken up by frost action so that much of a rock is buried inder a cover of angular sharp boulders.
Freeze Thaw weathering breaks up the top layer of the rock.
only form on slopes lower than 25°
Eg Rockies in Colorado

Question 4

Solifluction

Answer 4

1. Caused by the active layer thawing in the summer
2. excessive water reduces friction between soil particles
3. parts of the active layer moving down the slope
4. lobate shaped masses form debris
5. these are rounded, tongue-like features that form terraces

Question 5

Ice wedges

Answer 5

The refreezing of the active layer causes the soil to contract
cracks open during the summer
meltwater enters the cracks
the cycle repeats every year deepening and widening the cracks
can be 1m wide and 2-3m deep

Question 6

Frost Heave

Answer 6

As the active layer starts to refreeze, ice crystals begin to develop which increase the volume of the soil, causing an upward expansion in the soil surface.
Within the soil, there are stones which because they have a low specific heat capacity, heat up and cool down faster than the surrounding soil.
The soil underneath the stone is likely to freeze before the other material, pushing the stone upwards until it reaches the surface.
This can form patterned ground as the larger stones move outwards rolling down hill.

Question 7

Closed system Pingos

Answer 7

A frozen lake with sediment on the floor insulates the ground beneath, allowing talik to exist.
Permafrost advances during the winter allowing unfrozen water to turn to ice.
Pressure increases and sediment is pushed up creating a mound.

Question 8

Corrie

Answer 8

a bowl-shaped hollow in a mountainside that is formed by glacial erosion.

Snow accumulates in a hollow on a mountainside. The snow is compressed by the weight of the snow that falls on top of it, squeezing out air and turning the snow into ice. Over time eroding the rock.

Question 9

Permafrost definiton

Answer 9

Permanently frozen ground where soil temperatures have been below 0° for at least 2 years.

Question 10

Internal Deformation

Answer 10

1. Ice crystals are jumbled.
2. Under pressure (greatest at the base) parallel lines form as the ice crystals align.
3. The ice crystals can now slide over one another due to the reduction of friction.
4. this forms crevasses.

Question 11

Basal Sliding(only in warm based glaciers)

Answer 11

Pressure between ice and an obstacle
this pressure causes ice to melt
water can flow around and refreeze

Question 12

Rate of movement of a glacier

Answer 12

Gravity (gradient)
Permeability of rock (impermeable=moves faster)
meltwater (more=moves more rapidly)
ice temperature
ice mass (more precipitation to add to mass it will advance faster)

Question 13

U shaped Valley

Answer 13

Corrie glaciers leaves source region and descends down old river valley
scouring occurs as glacier moves
a deep wide U shaped Valley is left

Question 14

Ribbon Lake

Answer 14

glacier moves over alternate bands of hard and soft rock
sharp edged boulders carried at base erode softer rock via abrasion
a rock basin is formed
harder rock around the edges is eroded less
rock bars form acting as a dam
rainwater fills up the rock basin
a ribbon lake forms

Question 15

Pyramidal Peak

Answer 15

-3 or more corries and aretes meet
-glaciers carve away at top of mountain
-an angular sharply pointed summit remains

Question 16

Arete

Answer 16

-corries erode backwards through plucking and abrasion
-back walls become steeper
-a sharp knife edge ridge is left

Question 17

Truncated Spurs

Answer 17

interlocking spurs are left behind from a river
abrasion and plucking erode tips of spurs
steep cliff like outcrops are left

Question 18

Misfit stream

Answer 18

a stream that can’t possibly have eroded the valley in which it flows

Question 19

Fjord

Answer 19

found in locations where the glacial erosion happened below sea level when the glacier retreats, sea water fills up the valley floor eg loch broom

Question 20

Hanging Valley

Answer 20

-form where two glacial valleys meet
-tributary valley glacier is smaller with less mass
-valley erode less
-main valley glacier is larger with greater mass
-valley is eroded more
-tributary valley is left hanging above main valley
-waterfall flows over the edge