Chapter 11 Vocab Glaciers And Glaciation Essentials Of Geology

Front 1

ablation

Back 1

A general term for the loss of ice and snow from a glacier

Front 2

abrasion

Back 2

The grinding and scraping of a rock surface by the friction and impact of rock particles carried by water, wind, or ice

Front 3

alpine glacier or valley glaciers

Back 3

A glacier confined to a mountain valley, which in most instances had previously been a stream valley

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arete

Back 4

A narrow, knifelike ridge separating two adjacent glaciated valleys.

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calving

Back 5

Wastage of a glacier that occurs when large pieces of ice break off into water.

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cirque

Back 6

An amphitheater-shaped basin at the head of a glaciated valley produced by frost wedging and plucking

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crevasse

Back 7

A deep crack in the brittle surface of a glacier.

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drumlin

Back 8

A streamlined asymmetrical hill composed of glacial till. The steep side of the hill faces the direction from which the ice evaporated.

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End Moraine

Back 9

A ridge of till marking a former position of the front of the glacier.

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esker

Back 10

Sinuous ridge composed largely of sand gravel deposited by a stream flowing in a tunnel beneath a glacier near its terminus.

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fiord

Back 11

A steep-sided inlet of the sea formed when a glacial trough was partially submerged.

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firn

Back 12

Granular recrystallized snow commonly make up old snowbanks near the end of winter.

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glacial budget

Back 13

The balance or lack of balance between accumulation at the upper end of a glacier, and loss at the other end.

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glacial drift

Back 14

An all-embracing term for sediments of glacial origin, no matter how, where, or in what shape they were deposited

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glacial erratic

Back 15

An ice-transported boulder that was not derived from the bedrock near its present site.

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glacial striations

Back 16

Scratches and grooves on bedrock caused by glacial abrasion

Front 17

glacial trough

Back 17

A mountain valley that has been widened, deepened, and straightened by a glacier

Front 18

glacier

Back 18

A thick mass of ice originating on land from teh compaction and recrystallization of snow. The ice shows evidence of past or present flow.

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ground moraine

Back 19

An undulating layer of till deposited as the ice front retreats.

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hanging valley

Back 20

A tributary valley that enters a glacial trough at a considerable height above the floor of the trough

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horn

Back 21

A pyramidlike peak formed by glacial action in three or more cirques surrounding a mountain summit

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ice cap

Back 22

A mass of glacial ice covering a high upland or plateau and spreading out radially

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ice sheet

Back 23

A very large thick mass of glacial ice flowing outward in all directions from one or more accumulation centers

Front 24

ice shelf

Back 24

large relatively flat masses of floating ice that extend seaward from the coast but remain attached to the land along one or more sides

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kame

Back 25

A steep-sided hill composed of sand and gravel originating when sediment collected in openings in stagnant glacial ice.

Front 26

kettle

Back 26

Depressions created when blocks of ice become lodged in glacial deposits and subsequently melt

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lateral moraine

Back 27

A ridge of till along the sides of a valley glacier composed primarily of debris that fell to the glacier from the valley walls.

Front 28

medial moraine

Back 28

A ridge of till formed when lateral moraines from two coalescing valley glaciers join.

Front 29

outlet glacier

Back 29

A tongue of ice normally flowing rapidly outward from an ice cap or ice sheet, usually through mountainous terrain to the sea.

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outwash plain

Back 30

A relatively flat, gently sloping plain consisting of materials deposited by meltwater streams in front of the margin of an ice sheet.

Front 31

pater noster lakes

Back 31

A chain of small lakes in a glacial trough that occupy basins created by glacial erosion

Front 32

piedmont glacier

Back 32

A glacier that forms when one or more valley glaciers emerge from the confining walls of mountain valleys and spread out to create a broad sheet in the lowlands at the base of the mountains

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pleistocene epoch

Back 33

An epoch of the Quaternary period beginning about 1.8 million years ago and ending about 10,000 years ago. Best known as a time of extensive continental ice sheets

Front 34

plucking

Back 34

The process by which pieces of bedrock are lifted out of place by a glacier

Front 35

pluvial lake

Back 35

A lake formed during a period of increased rainfall for example this occurred in many nonglaciated areas during periods of ice advance elsewhere

Front 36

roche moutonnee

Back 36

An asymmetrical knob of bedrock formed when glacial abrasion smoothes the gentle slope facing the advancing ice sheet and plucking steepens the opposite side as the ice overrides the knob.

Front 37

rock flour

Back 37

Ground-up rock produced by the grinding effect of a glacier.

Front 38

snowline

Back 38

Lower limit of perennial snow

Front 39

stratified drift

Back 39

Sediments deposited by glacial meltwater

Front 40

tarn

Back 40

A small lake in a Cirque

Front 41

till

Back 41

Unsorted sediment deposited directly by a glacier

Front 42

valley train

Back 42

A relatively narrow body of stratified drift deposited on a valley floor by meltwater streams that issue from the terminus of a valley glacier

Front 43

zone of accumulation

Back 43

The part of a glacier characterized by snow accumulation and ice formation. The outer limit of this zone is the snowline

Front 44

zone of wastage

Back 44

Below the snowline where there is a net loss to the glacier as all of the snow from the previous winter melts as well as glacial ice.

Front 45

till

Back 45

Unsorted sediment deposited directly by a glacier

Front 46

valley train

Back 46

A relatively narrow body of stratified drift deposited on a valley floor my meltwater streams that issue from the terminus of a valley glacier

Front 47

zone of accumulation

Back 47

The part of a glacier characterized by snow accumulation and ice formation. The outer limit of this zone is the snowline

Front 48

zone of wastage

Back 48

Below the snowline where there is a net loss to the glacier as all of the snow from the previous winter melts as well as glacial ice.

Front 49

abrasion

Back 49

The grinding and scraping of a rock surface by the friction and impact of rock particles carried by water, wind, or ice

Front 50

barchan dune

Back 50

A solitary sand dune shaped like a crescent with is tips pointed downwind

Front 51

barchanoid dune

Back 51

Dunes forming scalloped rows of sand oriented at right angles to the wind. This form is intermediate between isolated barchans and extensive waves of transverse dunes

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bed load

Back 52

Sediment rolled along the bottom of a stream by moving water, or particles rubbed along the ground surface by wind.

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blowout (deflation hollow)

Back 53

A depression excavated by wind in easily eroded materials

Front 54

cross beds

Back 54

Structure in which relatively thin layers are inclined at an angle to the main bedding. Formed by currents of wind or water

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deflation

Back 55

The lifting and removal of loose material by wind

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desert

Back 56

One of the two types of dry climate; the drier of the dry climates

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desert pavement

Back 57

A layer of coarse pebbles and gravel created when wind removes the finer material.

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dry climate

Back 58

A climate in which the yearly precipitation is less than the potential loss of water by evaporation

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dune

Back 59

A hill or ridge of wind-deposited sand

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ephemeral stream

Back 60

Only carry water in response to specific rainfalls. Occur in the deserts might only flow one day or a couple of hours or not at all

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interior damage

Back 61

A discontinuous pattern of intermittent streams that do no flow to the ocean

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loess

Back 62

Deposits of windblown silt, lacking visible layers, generally buff colored and capable of maintaining a nearly vertical cliff.

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longitudinal dune

Back 63

Long ridges of sand oriented parallel to the prevailing wind; these dunes form where sand supplies are limited

Front 64

parabolic dune

Back 64

A sand dune similar in shape toa barchan dune except that its tips point into the wind. these dunes often form along coasts that have strong onshore winds, abundant sand, and vegetation that partly covers the sand.

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playa lake

Back 65

A temporary lake in a playa

Front 66

rainshadow desert

Back 66

A dry area on the lee side of a mountain range. Many middle-latitude deserts are of this type

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saltation

Back 67

Transportation of sediment through a series of leaps or bounces

Front 68

slip face

Back 68

The steep, leeward surface of a sand dune that maintains a slope of about 34 degrees.

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star dune

Back 69

Isolated hill of sand that exhibits a complex form and develops where wind conditions are variable

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steppe

Back 70

One of the two types of dry climate. A marginal and more humid variant of the desert that separates the desert from bordering humid climates

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suspended load

Back 71

The fine sediment carried within the body of flowing water or air

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transverse dunde

Back 72

A series of long ridges oriented at right angles to the prevailing wind; these dunes form where vegetation is sparse and sand is plentiful

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ventifact

Back 73

A cobble or pebble polished and shaped by the sandblasting effect of wind

Front 74

yardang

Back 74

A streamlined, wind-sculpted ridge having the appearance of an inverted ship's hull that is oriented parallel to the prevailing wind