Gcse- Plate Tectonics

Question 1

How are earthquakes and volcanoes caused?

Answer 1

Caused by eruptions caused by movement within the earth

Question 2

What belts do earthquakes occur in?

Answer 2

Pacific Ocean
Mid-Atlantic ocean
Stretch across Southern Europe and Asian

Question 3

What does the earth consist of?

Answer 3

Middle- core
Outer middle- mantle
Surface layer- crust
Outer- plays boundary

Question 4

Where do earthquakes and volcanoes occur at?

Answer 4

They occur at narrow zones of activity

Question 5

What is crust broken into?

Answer 5

Crust is broken into segments known as plates which can float on mantle.

Question 6

What happens with heat within the earth?

Answer 6

Heat within the earth creates convection currents convection currents which cause plates to move.

Question 7

Where do most earthquakes and volcanic eruptions occur?

Answer 7

Where plates meet at a plate boundary.

Question 8

What do most plates consist of?

Answer 8

Continental crust and oceanic crust

Question 9

Characteristics of oceanic crust-

Answer 9

Young
Heavy
Can sink and is constantly getting destroyed.

Question 10

Characteristics of continental crust-

Answer 10

Old
Light
Cannot sink and is permanent

Question 11

What do crust differences account for?

Answer 11

Crust differences account for variation in processes and landforms, and level of activity at plate boundaries.

Question 12

Describe what happens at a constructive plate margin-

Answer 12

2 plates move away from eachother. Oceanic crust appears forming mid-oven ridge with volcano. Gentle volcanic and earthquake activity.

Question 13

Describe what happens at a destructive plate margin-

Answer 13

Oceanic crust moves towards continental crust, but because it’s heavier, it sinks and get destroyed forming an island arc. Violent volcanic and earthquake activity.

Question 14

Describe what happens at collision zones-

Answer 14

2 continental crusts collide, neither sinks so they are forced upwards to form fold mountains. Can be violent earthquake activity.

Question 15

Describe what happens at conservative margins-

Answer 15

2 plates move sideways past eachother, land isn’t formed or destroyed. Can be violent earthquake activity.

Question 16

What happens at constructive margin(more expansive)

Answer 16

2 plates move away from eachother, magma rises to fill gaps and form new oceanic crust. Process is called sea-floor spreading.

Question 17

What occurs at destructive plate margins?(expand)

Answer 17

Plates consisting of oceanic crust move towards plates of continental crust. In the South Pacific Ocean, nazca plate is forced downwards to form subduction zone and deep sea trench. Increase in pressure as plate is forced downwards can trigger earthquakes. As oceanic crust descends, it melts due to heat from friction caused by contact with South America plate.

Question 18

What occurs at collision margins? (Expand)

Answer 18

2 plates consisting of continental crust move together. Continental crust can’t be sunk or destroyed, rocks between are forced up to form fold mountains.

Question 19

What happens at conservative margins? (Expand)

Answer 19

2 plates slide past eachother. As crust is neither formed or destroyed, new landforms are not created and there is no volcanic activity. Earthquakes occur when plates stick. This is situation in San Andreas fault. When pressure builds one plate jerks forward sending shockwaves to surface cause earthquake.