Glaciation - AS

?
  • Created by: aminaamri
  • Created on: 12-05-17 21:34
What is a system?
A system is a set of interrelated elements comprising components (stores) and processes (links) that are connected together to form a working unit,
1 of 63
What are inputs into a glacial system?
Precipitation, Meltwater, Debris and heat
2 of 63
What are the throughputs of a glacial system?
Snow, ice, debris and meltwater
3 of 63
What are the outputs of a glacial system?
Water Vapour, Debris, Heat and lakes, rivers & streams
4 of 63
What are the 3 forms of energy in glaciated landscapes?
Kinetic, Thermal and Potential
5 of 63
What is glacial mass balance?
The difference between the amount of snow and ice accumulation & the amount of ablation occurring in a glacier over a 1 year time period.
6 of 63
What is ablation?
Includes all losses of ice from a glacier, including meltwater, evaporation, sublimation & iceberg carving
7 of 63
What is accumulation?
Snow, ice from direct precipitation, avalanches and windblown snow
8 of 63
What physical factors affect glaciers?
Latitude, Alittude, Aspect, Climate, Geology, Glacial movement, deposition, meltwater, relief and erosion.
9 of 63
What is a niche?
Small glaciers on upland slopes
10 of 63
What is a Corrie?
Ice masses on mountain sides in an armchair shaped hollow
11 of 63
What is a Valley Glacier?
a glacier that flows odwn a valley's being fed by corries or ice fields
12 of 63
What is a piedmont glacier?
Glaciers spreading out when they are leaving their valley.
13 of 63
What is an ice cap?
Large plateaus of ice on high land
14 of 63
What is an icesheet?
Large expanses of ice- larger than an icecap
15 of 63
What is a cold-based glacier?
Found in polar regions the glacier is ice through to the bedrock. Found in high latitude locations. Areas with low relief. Have a slow rate of movement.
16 of 63
What is a warm based glacier?
The glacier has meltwater at the bottom acting as lubricant for ice movement. Found in high altitude locations with steep relief, Have a fast rate of movement.
17 of 63
What is basal sliding?
The glacier sliding over the bedrock due to meltwater under the ice acting as a lubricant.
18 of 63
What does basal sliding depend on?
Gradient, temperature, bed roughness, amount of meltwater and glacier size.
19 of 63
What is Internal deformation?
Ice deforms under its own weight due to gravity & the movement of tiny crystals inside the ice.
20 of 63
What are the 2 main types of internal deformation?
Creep and Faulting
21 of 63
What is creep & faulting?
Creep- forms fold structures. Faulting- When ice cannot creep at a fast enough rate & forms superficial tensional fractures.
22 of 63
What are the glacial & geomorphic processes?
weathering, mass movement, erosion, and Nivation
23 of 63
Examples of Physical weathering.
Freeze thaw, frost shattering & pressure release
24 of 63
Examples of chemical weathering.
Weak acid in rain, CO2 dissolved in water- can react with CaCO3- (carbonation) becoming soluble
25 of 63
Examples of biological weathering.
Plants and animals (not much)
26 of 63
What are the 2 types of mass movement?
Rockfalls, Slides
27 of 63
What is a rock fall?
Rock detached by weathering, falls down slope creating angled scree slope
28 of 63
What are slides?
Due to steeping or undercutting valley. Slides can be rotational.
29 of 63
What are the 2 types of erosion?
Plucking, Abrasion.
30 of 63
What is Plucking?
When meltwater seeps into the joints in the rock of valley sides/ floor. This freezes and joins to the glacier. As the glacier advances it pulls pieces out with it.
31 of 63
What is Abrasion?
As the glacier moves across the rock, debris embedded in the rock scours it. Prodcures 'Rock flour' as debris is abraded. Rock flour creates the milky white appearance of meltwater.
32 of 63
What is Nivation?
Nivation is the combination of freeze thaw action and solifluction.
33 of 63
What is Solifluction?
The gradual movement of wet soil & other material down a slope, especially where frozen subsoil acts as a barrier to the percolation of water.
34 of 63
How is a corrie formed?
Temperatures under 0 degrees, snow compacts into firn. The weight of the firn adds pressure and meltwater causes rotational slip to occur. Plucking then occurs on the back wall.
35 of 63
What is an Arete?
Thin knife edge ridge causes by 2 corries back to back
36 of 63
What is a pyramidal peak?
3 or more corries creating a pyramid at the top
37 of 63
What are striations caused by?
Caused by abrasion from debris found in glacial ice. That scraps across the rock as the glacier moves over the rock.
38 of 63
How is a trough formed?
Glacier flows down v-shaped valley due to gravity. Mass of ice forms it into a U-shape. Steep sides. Scree accumulates at the base of the valley sides and lessen the slope angle.
39 of 63
How is a Roche Mountonee formed?
Smoothed by ice. Affected by plucking. Resistant rock that is more difficult to erode becomes smoothed. Abrasion leaves striations on the rock.
40 of 63
What are the Erosional Landforms?
Corries, Aretes, Pyramidal peak, Striations, Trough, Roche Moutonee and Truncated spurs.
41 of 63
What are the depositional landforms?
Erratic, Drumlin, Till sheet, Terminal morraine, Recessional morraine and lateral morraine
42 of 63
How is an Erratic formed?
Plucking occurs on a rock side of a glacier, the removed rock then got transported by the glacier/meltwater. The rock is then deposited and left in a new environment. The rock has a different lithology to the surrounding rock.
43 of 63
How is Drumlin formed?
Formed when ice is melting nad overloaded in a lowland area. Reshaping of previously deposited material. Formation not fully understood.
44 of 63
How is a till sheet formed ?
When a large mass of unstratified drift is deposited at the end of a period of ice sheets which smooths the underlying surface. It is made from unsorted rock, clay and sand.
45 of 63
What is terminal morraine?
Marks the maximum advance of the glacier. Ridge of material stretching across the glacier. Sometimes creates a dam.
46 of 63
What is recessional morraine?
Right angle to ice flow. The glacier has more than 1 recession. Smaller than a terminal morraine but made in the same way just further back.
47 of 63
What is lateral morraine?
Different types of rock that have been deposited along the edge of the glacier.
48 of 63
What is a fluvial landform?
Formed by meltwater from a retreating glacier.
49 of 63
What are the glacial- fluvial landforms?
Outwash plains, Varves, Kames and Eskers
50 of 63
What is an outwash plain?
Usually flat and consists of layers of sand and other fine sediments. Deposited by meltwater & streams from ice during the summer or deglacial period
51 of 63
What is a Varve?
Distinct layers of slit lying on top of a lyaer of sand, deposited annually, found near glacial margins.
52 of 63
What can you tell from the layers in a varve?
The coarser lighter coloured sand is deposited during the late spring when meltwater streams are at their peak load. As discharge decreases towards autumn when temp. drops. The silt is darker & finer
53 of 63
What is an Esker?
Very long, narrow sinous ridges of sorted coarse sand & gravel. They are the fossilized courses of subglacial meltwater streams.
54 of 63
How are Eskers formed?
Within Ice-walled tunnels that had streams that flowed in & under glaciers. Streams deposits remained as long winding ridges.
55 of 63
What is a Kame?
Mounds of sediment that consist of sand & gravel that has built up into a mound. As the glacier melts, more sediment is deposited on top of the old debris. Unsupported kames tend to collapse & leave a mound.
56 of 63
What is a perigacial landscape?
Somewhere that experiences temp. variations allowing permafrost to occur. Free thaw systems dominate the land. Ice melting and refreezing.
57 of 63
What is Frost Heave?
Sub-surface process that leads to a vertical sorting of material in the active layer. As the temp falls- water beneath the stones freezes, expands, causing the stones to be pushed out.
58 of 63
What the periglacail landforms?
Patterned ground and Pingos.
59 of 63
What is patterned ground?
Result of frost heave. The stones that are pushed out form a network of stone polygons
60 of 63
What is a pingo?
Round ice covered hills. Can be open system or closed system.
61 of 63
What is an open system pingo?
Formed in a valley bottom, the water from the surrounding slopes collects under gravity. This water freezes and expands. The overlying surface material is forced into a dome.
62 of 63
What is a closed- system pingo?
Developed beneath a lake. The water supply is the immediate local area. Causes a build up of talik under the lake. Once this freezes it causes the lake bed to rise.
63 of 63

Other cards in this set

Card 2

Front

Precipitation, Meltwater, Debris and heat

Back

What are inputs into a glacial system?

Card 3

Front

Snow, ice, debris and meltwater

Back

Preview of the back of card 3

Card 4

Front

Water Vapour, Debris, Heat and lakes, rivers & streams

Back

Preview of the back of card 4

Card 5

Front

Kinetic, Thermal and Potential

Back

Preview of the back of card 5
View more cards

Comments

BigDickPav

Report

Oh my god this specimen has a mental capacity worse than ya boi Joe Smith KYS

roshnijaya

Report

thank you so much for this!!!!! Such a great help 2 bad u can't even spell DOWN  xxxxxxxxxxxxx

Similar Geography resources:

See all Geography resources »See all glaciation resources »