Unit 5 - Erosion, Weathering, and Landforms

Question 1

What is weathering?

Answer 1

The process in which materials on or near Earth’s surface break down and change.

Weathering includes both mechanical and chemical processes.

Question 2

What is erosion?

Answer 2

The removal of weathered rock and soil from its original location.

Erosion transports materials via agents like water, wind, and ice.

Question 3

What are the two main types of weathering?

Answer 3

Mechanical weathering and Chemical weathering

Question 4

What is mechanical weathering?

Answer 4

A type of weathering in which rocks and minerals break down into smaller pieces.

Examples include ice wedging, exfoliation, pressure, tree roots, and uplift.

Question 5

What is chemical weathering?

Answer 5

The process by which rocks and minerals undergo changes to their composition.

Examples include water dissolution, oxidation, and reactions with acids.

Question 6

In what kind of environment would you expect to see more chemical weathering?

Answer 6

In climates with warm temperatures, abundant rainfall, and lush vegetation.

Question 7

What factors influence rates of weathering?

Answer 7

Rock Type and Composition; Surface Area; Topography

Question 8

How does rock type affect weathering?

Answer 8

Different kinds of rock have different levels of resistance to weathering.

Question 9

What role does surface area play in mechanical weathering?

Answer 9

As rocks break into smaller pieces, the surface area available to be weathered increases, thus accelerating the rate of weathering.

Question 10

What is topography’s effect on weathering?

Answer 10

Level ground is more resistant to weathering than slopes.

Question 11

What are the agents of erosion?

Answer 11

Gravity; Water; Glaciers; Wind; Living Things

Question 12

What is the role of gravity in erosion?

Answer 12

Gravity pulls weathered materials down slopes, causing mass movements.

Question 13

What is mass movement?

Answer 13

The downslope movement of soil and weathered rock resulting from the force of gravity.

Question 14

What are the types of mass movement?

Answer 14

Creep; Flow; Slide; Slump; Avalanche; Rockfalls

Question 15

What is creep in terms of mass movement?

Answer 15

Slow, steady downhill flow of loose, weathered Earth materials such as soil.

Question 16

What is flow in terms of mass movement?

Answer 16

When weathered Earth materials flow as if they were a thick liquid, such as a mudflow.

Question 17

What is slide in terms of mass movement?

Answer 17

A rapid, downslope movement of Earth materials that occurs when a relatively thick block of soil, rock, and debris separates from the underlying bedrock.

Question 18

What is slump in terms of mass movement?

Answer 18

When the mass of materials in a landslide moves along a curved surface.

Question 19

What is an avalanche?

Answer 19

Landslides that occur in mountainous areas with thick accumulations of snow.

Question 20

What are rockfalls?

Answer 20

On high cliffs, rocks are loosened by mechanical weathering processes such as freezing, thawing, and plant growth.

Question 21

How does water erode Earth materials?

Answer 21

Rill erosion; Gully erosion; Rivers and streams; Wave action

Question 22

What is rill erosion?

Answer 22

When running water cuts small channels into the side of a slope.

Question 23

What is gully erosion?

Answer 23

When a channel becomes deep and wide as a result of further erosion.

Question 24

How do glaciers erode Earth materials?

Answer 24

Glaciers scrape and gouge out large sections of Earth’s landscape, moving as dense, enormous rivers of slowly flowing ice.

Question 25

What are the characteristic landforms created by glaciers?

Answer 25

U-shaped valleys; Lakes

Question 26

How is wind a force of erosion?

Answer 26

Wind is particularly powerful in coastal and arid regions, moving dry particles, sometimes with such force it can move things uphill.

Question 27

How do living things contribute to erosion?

Answer 27

Plant roots move and loosen soil; Animals can burrow tunnels into the soil; Humans excavate during construction

Question 28

What is the process called that results in the lowering of the land surface due to wind?

Answer 28

Deflation ## Footnote Deflation is the removal of surface particles by wind.

Question 29

What is abrasion in the context of wind erosion?

Answer 29

Abrasion is when particles rub against the surface of rocks or other materials. ## Footnote Rocks shaped by windblown sediments are called ventifacts.

Question 30

What happens during deposition?

Answer 30

Suspended particles drop when wind velocity decreases. ## Footnote This occurs because the particles can no longer remain aloft.

Question 31

What are dunes formed by?

Answer 31

Dunes are formed when an object blocks the forward movement of windblown particles. ## Footnote Objects can include rocks, landforms, or vegetation.

Question 32

What are the two main types of glaciers?

Answer 32

Valley glaciers and Continental glaciers ## Footnote Valley glaciers form in mountainous areas, while continental glaciers cover broad areas.

Question 33

What is the zone of accumulation on a glacier?

Answer 33

An area where more snow falls than melts, evaporates, or sublimates. ## Footnote This zone is crucial for glacier growth.

Question 34

What is a cirque?

Answer 34

A bowl-shaped depression hollowed out by glacial snow accumulation. ## Footnote Cirques are often found at the heads of glacial valleys.

Question 35

What is an arete?

Answer 35

A sharp ridge formed by two cirques on opposite sides. ## Footnote Aretes are typically found in mountainous regions.

Question 36

Define a horn in glacial geography.

Answer 36

A pyramidal peak formed when glaciers are present on three or more sides of a mountaintop. ## Footnote Horns are iconic features of glaciated landscapes.

Question 37

What are moraines?

Answer 37

Unsorted till deposited by a glacier. ## Footnote Moraines can indicate the former extent of a glacier.

Question 38

What is runoff?

Answer 38

Water flowing downslope along Earth’s surface. ## Footnote Runoff occurs when water does not infiltrate into the soil.

Question 39

What are the four main factors that impact whether water will infiltrate or runoff?

Answer 39

Soil composition; Rate of precipitation; Vegetation; Slope ## Footnote These factors interact to determine water absorption and movement.

Question 40

How does soil composition affect water infiltration?

Answer 40

It determines the soil's water-holding capacity. ## Footnote Soil is made of humus and minerals, with varying particle sizes.

Question 41

What type of precipitation is more beneficial for water infiltration?

Answer 41

Light, gentle precipitation ## Footnote It causes less erosion by runoff compared to heavy downpours.

Question 42

How does vegetation influence water infiltration?

Answer 42

Vegetation slows water flow and allows more time for soil absorption. ## Footnote Areas without vegetation can lead to soil compaction and reduced infiltration.

Question 43

How does slope impact water runoff?

Answer 43

Steeper slopes allow for more runoff and erosion. ## Footnote Flat grades facilitate greater water infiltration.

Question 44

What is groundwater?

Answer 44

Water present beneath the earth's surface and stored in aquifers. ## Footnote Groundwater is a crucial resource for drinking water and irrigation.

Question 45

Define aquifer.

Answer 45

Permeable zones where groundwater is filtered and stored. ## Footnote Aquifers can vary in size and depth.

Question 46

What are large bodies of water runoff called?

Answer 46

Streams ## Footnote Streams are formed when surface runoff collects in small channels.

Question 47

What are tributaries?

Answer 47

Rivers and streams that join with a larger body. ## Footnote Tributaries contribute to the flow of larger rivers.

Question 48

What is a watershed?

Answer 48

All of the land area whose water drains into a stream system. ## Footnote The Mississippi River watershed is the largest in the US.

Question 49

What is a divide?

Answer 49

An elevated land area that separates one watershed from another. ## Footnote Divides help determine the flow direction of water.

Question 50

What is stream load?

Answer 50

Material that the stream carries. ## Footnote Stream load includes sediment and dissolved materials.

Question 51

What are the three types of materials in stream load?

Answer 51

Materials in suspension; Bed load; Materials in solution. ## Footnote Each type is transported differently based on particle size and water turbulence.

Question 52

What is stream carrying capacity?

Answer 52

The ability of the stream to transport material. ## Footnote It depends on the stream's velocity and the amount of water.

Question 53

What factors affect stream velocity?

Answer 53

Slope; Depth; Width; Level of friction ## Footnote These factors influence how quickly water flows through a stream.

Question 54

What is discharge in relation to a stream?

Answer 54

The volume of stream water that flows past a particular location within a given period of time. ## Footnote Discharge is calculated using the formula WXDXV.

Question 55

What happens to carrying capacity as discharge increases?

Answer 55

Carrying capacity increases with discharge. ## Footnote More water allows streams to transport larger amounts of sediment.

Question 56

What happens as stream channels develop into broader valleys?

Answer 56

The volume of water and sediment they can carry increases ## Footnote Energy for downward erosion decreases in this zone.

Question 57

What is a flood?

Answer 57

When more water pours into a stream than the banks can hold ## Footnote Floods cause water to spill over onto adjacent land.

Question 58

What is a floodplain?

Answer 58

The area of land extending out from a stream bank that becomes covered in excess water ## Footnote Floodplains are important for agriculture due to rich sediment deposits.