Glaciation Geography Processes and Landforms

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
meltwater reduces subglacial friction allows for basal sliding

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

Question 21

Erratic

Answer 21

Large Boulder that has been deposited when the glacier loses carrying capacity
its geology is different than the area it is found in
eg Norber Erratics, N Yorkshire

Question 22

Drumlin

Answer 22

formed by till
the stoss end is steeper and the lee end is more shallow
they are commonly found in groups called a swarm
there are 2 theories on how they are made

Question 23

Morraine

Answer 23

medial
lateral
terminal
recessional
push

Question 24

Outwash Plain

Answer 24

located at the snout of the glacier
the meltwater streams deposit gravel, sand and clay throughout summer.
hydrostatic pressure is lost outside the glacier, causing material to be deposited
larger material is deposited close to the glacier as the water loses cc
eg Red glacier, Alaska

Question 25

Braided Stream (always found witj outwash plain)

Answer 25

seasonal melt variants fluctuation in sediment load
excess sediment during low discharge disrupts the flow
rhe channel braids as it looks for a more efficent way to move

Question 26

Esker eg American Canada border

Answer 26

formed by subglacial flow
it is a long ridge of sediment running in the direction of flow
made of sorted sand and gravel

Question 27

Kame

Answer 27

a hill composed of stratified sand and gravel
laid down by glacial meltwater
deposited along the front of a slowly melting or stationary glacier
will collapse when the ice retreats
commonly found in cold based glaciers as there is lower hydrostatic pressure

Question 28

kame terrace

Answer 28

sorted sand and gravel forming along the sides of a glacier
deposited by meltwater streams following along the sides of the ice
warm rock melts the ice close to it forming a long depression along which a meltwater stream can flow

Question 29

Proglacial lake

Answer 29

cant have without terminal morraine
a lake developed immediately in front of a glacier, damned by terminal moraine

Question 30

Kettle Hole

Answer 30

dead ice is left on outwash plain by a retreating glacier
meltwater streams bury blocks of ice under sediment deposits
the ice melts and leaves a depression in the outwash plain

Question 31

Varve

Answer 31

lakes on the fringes of the ice are fillied with layers of deposits
a varve is a layer of silt lying on top of a layer of sand, deposited over a year.
can be used to show past climates and warmer cooler conditions as finer silts (winter) and thicker in summer