Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Geology 161 Final > ch12 flashcards > Flashcards

ch12 flashcards

(53 cards)

Start Studying
1
Q

basal slippage

A

The process by which a glacier slides over the underlying bedrock, aided by meltwater acting as a lubricant at its base

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

plastic flow

A

The internal deformation of glacial ice, occurring below the rigid zone, where ice under pressure flows like a viscous fluid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

rigid zone

A

The upper part of a glacier where ice is not under enough pressure to flow plastically, causing it to fracture and form crevasses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

zone of accumulation

A

The area of a glacier where snowfall and other forms of precipitation add more ice than is lost, causing the glacier to grow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

zone of ablation (wastage)

A

The area of a glacier where ice is lost through melting, sublimation, or calving, reducing the glacier’s overall mass

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

snowline

A

The elevation above which snow remains year-round, marking the boundary between the zone of accumulation and the zone of ablation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

erosion (by glaciers)

A

The removal and transport of rock and sediment by a moving glacier, primarily through abrasion and plucking

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

abrasion (glacial)

A

The grinding and scraping of underlying rock by the sediment-laden ice, producing rock flour and striations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

plucking

A

The process by which a glacier picks up and removes chunks of bedrock as water freezes in cracks and then moves with the glacier

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

horn

A

A sharp, pyramid-shaped peak formed by the intersection of three or more cirques eroding a single mountain mass

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

arete

A

A narrow, knife-like ridge formed between two adjacent glacial valleys or cirques

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

cirque

A

A bowl-shaped depression at the head of a glacial valley, formed by erosion beneath the zone of accumulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

col

A

A mountain pass or low point along an arete, formed when two cirques on opposite sides of a ridge meet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

tarn

A

A small mountain lake or pool that forms in the depression of a glacial cirque once the ice has melted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

U-shaped valley

A

A valley with a broad, rounded cross section carved by a glacier, distinguishing it from a V-shaped stream-cut valley

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

hanging valley

A

A smaller glacial valley perched above a main U-shaped valley, often with a waterfall at the junction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

fjord

A

A glacially carved U-shaped valley that has been submerged by rising sea level, creating a deep, steep-sided inlet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

outwash plain

A

A broad, flat area in front of a glacier formed by sediment-laden meltwater streams that deposit well-sorted sands and gravels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

valley train

A

A confined outwash deposit formed within the valley of an alpine glacier, consisting of sediment carried and deposited by meltwater

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

moraine lake

A

A lake formed when a moraine acts as a natural dam, trapping meltwater and forming a basin of standing water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

kettle

A

A depression formed in glacial deposits by the melting of a buried ice block; often fills with water to form a kettle lake

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

esker

Study These Flashcards
A

A long, winding ridge of stratified sand and gravel deposited by a meltwater stream flowing beneath or within a glacier

23
Q

moraine

Study These Flashcards
A

An accumulation of unsorted, unstratified glacial till deposited along the edges or terminus of a glacier

24
Q

terminal moraine

Study These Flashcards
A

A ridge of till marking the furthest advance of a glacier’s snout or terminus

25
lateral moraine
A ridge of till deposited along the sides of an alpine glacier where it meets the valley walls
26
recessional moraine
A ridge of till deposited during a temporary halt in a glacier’s retreat, set behind the terminal moraine
27
medial moraine
A ridge of till formed when two alpine glaciers merge, and their lateral moraines join in the center of the combined glacier
28
ground moraine
A thin, widespread layer of till left by a glacier as it retreats, covering the landscape like a blanket
29
ice age
A period of long-term reduction in Earth’s temperature leading to the expansion of continental and polar ice sheets
30
pluvial lake
A lake formed in arid regions during wetter climates, often associated with glacial periods when precipitation was higher
31
isostatic rebound
The rise of Earth’s crust after the removal of ice load from glaciers, as the crust returns to its equilibrium level
32
deranged stream
A drainage system disrupted by glacial activity, lacking an organized pattern and often containing swamps, lakes, and randomly flowing channels
33
sea level change (glacial influence)
The fluctuation of global sea levels during ice ages, as large amounts of water become stored in glaciers, lowering sea level, and released when glaciers melt, raising it
34
alpine (valley) glaciers
Glaciers confined to mountain valleys, flowing from higher to lower elevations, carving steep and rugged topography
35
continental ice sheets
Vast, continuous masses of glacial ice that cover large portions of continents, such as those in Antarctica and Greenland
36
advancing glacier
A glacier with a positive mass balance where accumulation exceeds ablation, causing it to move forward
37
alpine glaciation
Glacial activity confined to mountainous regions, creating distinctive landforms like horns, aretes, and cirques
38
continental glaciation
Glacial activity on a continental scale, with ice sheets covering large areas of land and reshaping entire landscapes
39
drumlin
An elongated hill formed by glacial deposition, shaped like an inverted spoon with the tapered end pointing in the direction of ice flow
40
end moraine
A type of terminal or recessional moraine marking the previous extent of a glacier
41
erratic
A large boulder transported and deposited by a glacier far from its original location, differing in composition from local bedrock
42
iceberg
A large mass of floating ice detached from a glacier or ice shelf into a body of open water
43
ice cap
A smaller ice sheet covering less than 50,000 square kilometers, typically over a highland area
44
ice sheet
A massive, continent-sized glacier covering extensive land areas, often thousands of meters thick
45
outwash
Stratified sediment deposited by meltwater streams beyond the terminus of a glacier, forming outwash plains or valley trains
46
receding glacier
A glacier experiencing a negative mass balance where ablation exceeds accumulation, causing the glacier to retreat upslope
47
rock-basin lake
A lake formed in a basin eroded by a glacier into bedrock, often found in glacially carved valleys
48
rock flour
Fine sediment (silt and clay) produced by glacial abrasion, often giving glacial meltwater a milky appearance
49
terminus
The downslope end of a glacier where ice melts, breaks off as icebergs, or otherwise ablates
50
theory of glacial ages
The scientific understanding that multiple ice ages have occurred throughout Earth’s history, influenced by changes in climate, continental positions, and atmospheric composition
51
till
Unsorted and unstratified glacial sediment deposited directly by ice, composed of a mix of particle sizes
52
tillite
Lithified till, a sedimentary rock formed when glacial till becomes cemented over geologic time
53
valley glacier (alpine glacier)
A glacier confined to a mountainous valley, flowing from higher to lower elevations and carving distinctive valley shapes

Geology 161 Final (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions