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Flashcards in Glaciers Deck (19):
1

Ablation

The loss off ice or snow from glaciers. This can occur by melting, by evaporation, and by icebergs breaking off of a glacier borders a sea or a lake

2

Ablation Zone

The lower area of a glacier where the rate of ablation is higher than the rate of accumulation

3

Accumulation

The gain of snow and ice in a glacier. This is usually from precipitation in the form of snow, but also includes snow blown onto the glacier from surrounding slopes

4

Accumulation Zone

The upper area of a glacier where the rate of accumulation is higher than the rate of ablation

5

Advance (of a glacier)

Occurs over a time period when accumulation averaged across the whole glacier exceeds ablation averaged across the whole glacier. The glacier becomes larger and extends further

6

Calving

Where glaciers reach the sea or a lake, it is the process by which pieces of the glacier break off and float away

7

Crevasses

Fractures (or breaks) that can be seen at the surface of the glacier cause by stretching (extending) of the ice

8

Equilibrium Line

The boundary between a glacier's accumulation zone and its ablation zone. Along this boundary, averaged over the year, accumulation is equal to the amount of ablation

9

Glacier Ice

Ice formed from snow which has been compacted by the weight of snow being added above it. The pressure forces the glacier ice to move downslope

10

Glacier Terminus

The downward end of the glacier

11

Mass Balance

The relation between accumulation and ablation for a glacier (also called 'glacier budget'). It is positive if over a year there is more accumulation than ablation. It is negative if there is more ablation than accumulation

12

Moraine

Accumulations of rock debris being transported or deposited by a glacier. This term also refers to the landforms made of the debris after it has been deposited by the glacier

13

Retreat (of a glacier)

Occurs over a time period when ablation averaged across the whole glacier exceeds accumulation averaged across the whole glacier. The glacier becomes smaller and the end of the glacier goes back

14

Snout

The lower part of a valley glacier's ablation zone

15

Striations

When the glacier smoothly moves over the floor and the plucking makes lines in the rock

16

Crescentic Gouges

When the glacier is a lot more bumpy and moves of the floor and the plucking makes more bumpy marks in the floor than Striations

17

Chatter Marks

Holes in a rock that have been created by the glacier when plucking on a rock. Originally crescentic gouges

18

Arête

A steep sided ridge formed where corrie glaciers back on 2 sides

19

Pyramidal Peak

Where 3 glaciers erode 3 sides of a mountain peak leaving a triangle shaped peak