Landforms

Question 1

What is a landform?

Answer 1

Feature of the surface of the earth

Question 2

Positive landforms:

Answer 2

mountains, hills

Question 3

Negative landforms:

Answer 3

canyons, valleys

Question 4

What is the difference between a mountain and a hill:

Answer 4

amount of relief/elevation

Question 5

What is the difference between a canyon and a valley?

Answer 5

canyon: super steep walls
valley: not steep

Question 6

Flat landforms:

Answer 6

plains, plateaus

Question 7

A collection of landforms in an area make up a given terrain

Answer 7

• Some are flat, or undulating/rolling or rugged
• The relief (change in elevation) across a terrain may be described as: high, moderate, or low
• The slopes in these terrains may be described as: steep, moderate, or shallow

Question 8

Terrain types + description

Answer 8

• Mountainous terrains have high, rugged relief and steep slopes
• Hilly terrains have moderate, rolling relief with gentle slopes
• Flat terrains may slope gently or undulate
• Some terrains are mixed

Question 9

The details of terrains (distribution of landforms) are shown on:

Answer 9

topographic maps

Question 10

How do landforms form?

Answer 10

• Geologic processes cause portions of the land surface to move up or down relative to adjacent areas
• Upward movement = uplift
• Downward movement = subsidence

Question 11

A major cause of uplift and subsidence is:

Answer 11

plate tectonics, which squeeze and stretch the lithosphere in different places around the world

Question 12

Ocean-continent and continent-continent convergence produce:

Answer 12

mountains through squeezing the crust, can also result in volcanism and volcanic uplift

Question 13

Volcanic uplift is the result of:

Answer 13

material being added to the surface, hot rocks (at and below the surface) take up more space

Question 14

Uplift can also happen at divergent boundaries:

Answer 14

• new material added to the surface, hot rocks take up more space, newly added material moves away from ridge then cools and contracts
• Cooling = decrease in elevation

Question 15

What is subsidence caused by?

Answer 15

Stretching the crust (rifting/divergence) or when a load (downward force) is added to the crust

Question 16

Subsidence steps for squeezing the crust

Answer 16

1. Initially hot, rising rocks cause uplift
2. Stretching pulls the lithosphere apart, causing it to thin and the centre to drop (subsidence), producing a rift valley
3. Oceanic crust is thinner than continental crust
4. Continued divergence may produce a new ocean

Question 17

What happens when a load is added onto the crust?

Answer 17

• Crust flexes downward in response to load = subsidence
• Can also occur when materials are removed from the crust i.e oil/natural gas extraction, mining, dissolution of limestone, groundwater related

Question 18

Uplift and subsidence produce:

Answer 18

relief (differences in elevation) across a terrain

Question 19

Wherever relief develops, rocks are subjected to

Answer 19

weathering and erosion, weathered and eroded materials eventually get deposited

Question 20

The shape of landforms are modified by:

Answer 20

weathering, erosion, and deposition

Question 21

Erosion and deposition redistribute:

Answer 21

Sediment on Earth, stripping it from high spots and piling it up in low spots

Question 22

Even though weather, erosion, and deposition have operated on Earth for billions of years, Earth is not flat. Why?

Answer 22

Ongoing uplift and subsidence continue to move rocks up and down, changing the shape of the land

Question 23

Landforms produced through plate tectonics are called

Answer 23

tectonic landforms

Question 24

Landforms produced through volcanism are called

Answer 24

volcanic landforms

Question 25

Landforms produced through erosion are called

Answer 25

erosional landforms

Question 26

Landforms produced through sediment deposition are called

Answer 26

depositional landforms

Question 27

What are the six factors that control the formation of landforms?

Answer 27

1. Eroding agent 2. Relief 3. Climate factors 4. Substrate composition 5. Life activity 6. Time

Question 28

Eroding agent

Answer 28

- moving water, air, and ice produce landforms with different shapes because they carve into the land and carry the debris differently - i.e Glacial Valley = U-shaped, River Valley = V-shaped - Glacial deposits: poorly sorted, range of sizes. Wind deposits: well-sorted, small clasts

Question 29

Relief

Answer 29

the height and steepness of slopes determines whether rocks or soil will stay in place or tumble downslope, and how fast (controls velocity of water and ice).

Question 30

Climate factors (wind, rain, snow, temp, etc.)

Answer 30

- determine whether flowing ice, wind or water is the main agent of erosion and deposition. - affects the rate of weathering (warmer = faster weathering)

Question 31

Substrate composition

Answer 31

- Some earth materials are more resistant to erosion than others and can form steep cliffs. - Weak materials collapse and form gentle slopes.

Question 32

Life activity

Answer 32

- Some organisms weaken earth materials by burrowing or digesting them; others help bind loose materials together (tree roots). - The landforms that form in an area may be influenced by biological activity. - Humans alter the landscape and influence landform development i.e dams

Question 33

Time

Answer 33

landscapes evolve over time in response to continued erosion or deposition