Glaciated landscapes terminology Flashcards

Question

Rotational slip

Answer 1

- Ice flows in circular motion | - Erodes hollows and bowls in landscape

Answer 2

- Loose stones broken away from mountain sides by freeze-thaw - Slopes covered in angular loose stones

Answer 3

- Aka terminus or toe - End of a glacier - Always advancing or retreating

Answer 4

- Deep circular lake that forms within corries when ice has melted

Answer 5

- Ridge of rock debris deposited at the end of a glacier | - Mix of boulders, sand, gravel and clays

Answer 6

- Former river valley spur where ends are 'sliced' off by a valley glacier - Steep cliff-like edges

Answer 7

- Breakdown of material such as rock by physical (mechanical), chemical or biological processes

Answer 8

- Ice loss from a glacier or ice sheet - Melting, sublimation, evaporation, ice calving, avalanche etc. - Ablation zone where net loss occurs

Answer 9

- Build-up of glacial mass | - Accumulation zone where there is net accumulation

Answer 10

- Reflective capacity of material to return incoming solar radiation - White surfaces have high albedo effect - Feedback loop: if ice surfaces melt, more dark surfaces exposed, more rapid melting

Answer 11

- High enough temperatures produce meltwater at base | - Water reduces friction between ice and bedrock

Answer 12

- Deep crevasse along rear wall of a corrie | - Formed as ice moves away downhill

Answer 13

- Higher latitudes - Less seasonal variation in temperature, less meltwater - Moves by internal deformation

Answer 14

- When gradient is less steep, or ice moves over a major obstacle, it slows down - Crevasses close, fractures form in ice - Thicker ice increases mass and pressure, eroding more

Answer 15

- Moraine carried in glacial ice

Answer 16

- Long ridge of sediment deposited by meltwater from retreating ice

Answer 17

- When the gradient becomes steeper, the ice accelerates - Ice stretches, becomes thinner - Cracks and crevasses created at 90º to flow

Answer 18

- Term relating to erosion or deposition caused by flowing meltwater from glaciers or ice sheets

Answer 19

- Form of solifluction in periglacial environments - Downslope sliding movement of seasonally thawed and saturated soil - Assisted by permafrost

Answer 20

- Balance between inputs and outputs in glacial system | - Typically losses mass through evaporation and melting at snout

Answer 21

- Mostly in cold-based glaciers - Gravity and pressure in accumulation zone causes crystals to slide over each other, crumple and deform - Can form crevasses

Answer 22

- Aka kame terraces - Steep-sided flat-topped mound of gravel and sand - Deposited by meltwater from retreating ice - Terrace forms when sediment accumulates in ponds and lakes

Answer 23

- Rounded hollow filled by a lake, that forms due to a melting ice mass that is trapped within deposits

Answer 24

The net change in a glacier's mass over a year; this can be positive, if the glacier accumulates more mass than is lost through ablation, or negative, if there if more ablation that is accumulated

Answer 25

Weathered rock debris bands that run along the centre of a glacier, forming when lateral moraines from two glaciers merge together

Answer 26

Once all the ice has melted and a river returns to the deglaciated valley, it can look unexpectedly small in the scale of the wide glacial trough

Answer 27

A cylindrical vertical or near vertical shaft within a glacier, formed by surface meltwater percolating through a crack in the ice and scouring

Answer 28

Another form of ground ice, with slice of ice that penetrate down through the soil vertically - crucial to breaking up soil particles to loosen them for erosion and transportation

Answer 29

A group of processes such as freeze-thaw and mass wasting serve to carve out depressions and hollows in the ground, which can enlarge over time to form corries

Answer 30

An area adjacent to a glacier or ice sheet that is subjected to repeated freeze-thaw processes, a cold climate that commonly has permafrost, e.g. Canada, Greenland, Siberia

Answer 31

Hills that have an ice core, and are usually circular or dome-like in shape; the ice in the centre accumulates due to hydrostatic pressure or groundwater flow

Answer 32

The most recent epoch during which ice coverage was much greater than it is today, from approximately 2.5 million years ago until 11,800 years ago

Answer 33

Similar to terminal moraine, and are deposited wherever the snout remained static for long enough to accumulate debris

Answer 34

Layers of rock debris from the valley sides build up on the surface of the glaciers over time, and each successive winter it becomes embedded within the growing ice; bands of slowly rotating frozen rock then scrape over the bedrock to erode when ice moves downhill

Answer 35

A process of gradually moving wet soil or other material down slope, particularly when frozen subsoil acts as a barrier to prevent percolation of water; a form of slow mass movement

Answer 36

Grooves that are scratched into the bedrock below ice as the glacier moves and transports material down valley; these lines show in what direction the ice flowed

Answer 37

Irregular land surfaces found in periglacial landscapes that consist of alternating hills and hollows that are formed when permafrost thaws

Answer 38

When a large portion of ice becomes detached from the main glacier and melts, any suspended sediment within the ice will be deposited and form a large plain of unsorted till material

Answer 39

Also known as temperate glaciers, these are found at lower latitudes; temperatures around the glacier are warmer allowing ice to move more rapidly with increased liquid meltwater and basal sliding e.g. The Alps, The Rockies