Glacial Landforms

Question 1

abrasion

Answer 1

The process of rock material frozen to the underside of a glacier abrading the bedrock beneath as the glacier moves.

Question 2

arête

Answer 2

A sharp, steep, and narrow ridge that results from glaciers in two adjacent cirques or valleys. The glaciers wear back and steepen the slopes on either side.

Question 3

chatter marks

Answer 3

Crescent shaped marks and cracks on hard bedrock caused by rock debris underneath a glacier being dragged across it.

Question 4

cirque (also called ‘corrie’ and ‘cwm’)

Answer 4

Armchair or bowl-shaped hollows on the sides of mountains that either contain (or used to contain) glaciers.

Question 5

drumlins

Answer 5

Mounds of rock debris that originated beneath ice caps and ice sheets, and are therefore streamlined having a steeper, blunt ‘up-glacier’ side and a less steep, tapering ‘down-glacier’ side pointing in the direction that the glacier ice was flowing.

Question 6

erratic

Answer 6

A large rock or boulder that has been moved by a glacier far from its origin and dropped in an area of different rock type.

Question 7

fjord

Answer 7

A steep and narrow sea inlet which originated as a glaciated valley near the coast that became flooded by the sea as sea level rose.

Question 8

glacial trough (also called ‘U-shaped valley’)

Answer 8

Steep sided, relatively flat and broad bottomed valleys that either contain (or used to contain) valley glaciers.

Question 9

hanging valley

Answer 9

Formed from a smaller valley glacier joining a larger valley glacier. Once the glaciers have disappeared, the valley that was being worn down by the smaller glacier is not as deep, and where it meets the main valley there is a sudden drop - often containing a waterfall.

Question 10

horn (also called ‘pyramidal peak’)

Answer 10

A steep, isolated peak formed from glaciers wearing away a mountain summit from three or more sides.

Question 11

lateral moraine

Answer 11

Rock debris carried along the sides of a glacier. Once a glacier has retreated or disappeared, it is visible as ridges along the valley sides.

Question 12

plucking

Answer 12

The process of pulling out and removal of pieces of bedrock as they become frozen to the base of the glacier.

Question 13

push moraine

Answer 13

Rock debris pushed (bulldozed) by the front of an advancing glacier.

Question 14

roche moutonnée

Answer 14

A bedrock outcrop with a smoothed, abraded ‘up-glacier’ side and a steeper, ice plucked ‘down-glacier’ side.

Question 15

striae (or ‘striations’)

Answer 15

Scratches and grooves on hard bedrock caused by rock debris underneath a glacier aligned parallel with the direction the glacier was moving.

Question 16

terminal moraine

Answer 16

A ridge of rock debris marking the furthest position of a glacier’s advance. Once a glacier has retreated, this is visible as a ridge across the width of a valley.

Question 17

till

Answer 17

The specific term for rock debris directly deposited by glacier ice. It typically contains a mixture of particle sizes, ranging from tiny clay particles up to gravel and boulders.