Landforms And Volcanos

Question 1

What are the landforms at constructive margins?

Answer 1

Sea floor spreading
Rift valley

Question 2

How does Sea Floor Spreading occur?

Answer 2

• 2 plates move away from each other

• molten magma rises, creating new crust

• submarine volcanoes can form

• eg Mid-Atlantic Ridge

Question 3

How is a Rift Valley formed?

Answer 3

• 2 plates move away from each other

• molten magma rises, creating new crust

• eg Great African Rift Valley

Question 4

What are the landforms at a destructive margin?

Answer 4

Deep Sea Trench
Island Arcs

Question 5

How are Deep Sea Trenches formed?

Answer 5

• Continental and oceanic plates meet

• oceanic plate is subducted underneath

• eg Mariana Trench

Question 6

How are Island Arcs formed?

Answer 6

• Magma pushes up from the trenches creating a volcano

• the magma solidifies creating an island

• eg The Caribbean

Question 7

What is the landform at a collision margin?

Answer 7

Young Fold Mountains

Question 8

How are Young Fold Mountains formed?

Answer 8

• Continental plates meet

• Both plates push upwards

• eg Himalayas

Question 9

What are the landforms at conservative margins?

Answer 9

Fault lines

Question 10

How are fault lines formed?

Answer 10

• Two plates move parallel to each other

• crust is neither created or destroyed

• eg San Andreas Fault, California

Question 11

What is magma?

Answer 11

Molten rock below the surface

Question 12

What is lava?

Answer 12

Molten rock above the surface

Question 13

What is meant by extrusive?

Answer 13

When lava and other materials reach the surface

(Extrusive rocks formed on the surface of the Earth from lava)

Question 14

What is meant by intrusive?

Answer 14

Materials that are injected into the crust

(Intrusive rocks formed from magma that cools and solidifies within the crust of the planet)

Question 15

What is igneous rock?

Answer 15

Rocks that form from cooled magma

Question 16

What is pyroclastic material?

Answer 16

Material ejected from the volcano in fragmented form

Question 17

Where do fissure eruptions occur?

Answer 17

Constructive margins

Question 18

Describe a fissure eruption

Question 19

Where does a fissure eruption occur?

Answer 19

Constructive margin

Question 20

Describe a fissure eruption

Answer 20

• Occur when 2 plates move apart

• lava is ejected through fissures

• normally comprised of basalt

• the slow cooling of the lava produces columnar jointing

• lava fills up the hollow rather than creating a dome shape

• eg Giant’s Causeway, N. Ireland

Question 21

Where is a shield volcano found?

Answer 21

Constructive margins

Question 22

Describe the formation of a shield volcano

Answer 22

• Lava flows from a central vent

• lava spreads over a large area before solidifying

• results in a cone with long gentle sides

• volcano is made up of many layers

• eg Mauna Loa, Hawaii

Question 23

Where is a dome volcano formed?

Answer 23

Destructive margins

Question 24

Describe the formation of a dome volcano

Answer 24

• Lava flows from a central vent

• acid lava quickly solidifies

• steep sided, convex cone

• volcano is made up of many layers

• eg Mt St Helens, USA

Question 25

Where is an ash and cinder cone formed?

Answer 25

Destructive margin

Question 26

Describe the formation of an ash and cinder cone

Answer 26

• Fine ash and cinder is ejected from a central vent

• Layers of ash and cinder build up

• Shallow sided, concave sides

• volcano is made up of many layers

• eg Mt Etna, Italy

Question 27

Where is a caldera volcano formed?

Answer 27

Destructive margin

Question 28

Describe the formation of a caldera volcano

Answer 28

• Gas builds up in the magma chamber causing an explosion

• the sides of the subside

• craters can be flooded by the sea, creating lagoons

• eg Mt Mazama, USA