Glaciers

Question 1

Ablation

Answer 1

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

Question 2

Ablation Zone

Answer 2

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

Question 3

Accumulation

Answer 3

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

Question 4

Accumulation Zone

Answer 4

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

Question 5

Advance (of a glacier)

Answer 5

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

Question 6

Calving

Answer 6

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

Question 7

Crevasses

Answer 7

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

Question 8

Equilibrium Line

Answer 8

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

Question 9

Glacier Ice

Answer 9

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

Question 10

Glacier Terminus

Answer 10

The downward end of the glacier

Question 11

Mass Balance

Answer 11

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

Question 12

Moraine

Answer 12

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

Question 13

Retreat (of a glacier)

Answer 13

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

Question 14

Snout

Answer 14

The lower part of a valley glacier’s ablation zone

Question 15

Striations

Answer 15

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

Question 16

Crescentic Gouges

Answer 16

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

Question 17

Chatter Marks

Answer 17

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

Question 18

Arête

Answer 18

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

Question 19

Pyramidal Peak

Answer 19

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