Plate Tectonics

Question 1

What is a plate?

Answer 1

Section of the Earth’s crust that floats on thhe mantle

Question 2

What are the two types of plates?

Answer 2

Continental and Oceanic

Question 3

What are the four types of plate boundaries?

Answer 3

Destructive, Collision, Constructive, Conservative

Question 4

2 marks

What happens at a destructive plate boundary?

Subduction

Answer 4

An oceanic plate and a continental plate move towards each other and the oceanic plate sinks below

Question 5

What land forms occur at a destructive plate boundary?

Answer 5

Trenches, Fold mountains, Island arcs and sometimes volcanoes

Also earthquakes

Question 6

2 marks

Whate happens at collison boundaries ?

Answer 6

Two continental plates move towards each other

Question 7

what landforms occur at collision boundaries?

Answer 7

Fold mountains

also earthquakes

Question 8

2 marks

What happens at a Constructive plate boundary?

Answer 8

Two oceanic plates move away from eachother leading to gap similar to a valley

Question 9

What landforms occur at a constructive boundary?

Answer 9

Open trenches, Sea floor spreading. Possibly vocanoes

Question 10

2 marks

What happens at conseravative plate boundary?

Answer 10

Two plates move past eachother leading to very violent earthquakes

eg. San Andreas Fault

Question 11

Case Study - 7 marks

Effect of a volcano

Mt Merapi, Indonesia, 1994

Answer 11

Negative
Deaths/injuries; (60 deaths)
Destruction of homes;
Destruction of workplaces;
Destruction of specific buildings (e.g., schools, hospitals);
Damage to/blockage of roads;
Disruption to flights;
Damage to forests;
Loss of crops/farmland;
Permanent scarring due to thick smoke and ash of those in fields
Mud flows called lahars

Positive
Creation of fertile soil;
Minerals created or e.g.;
Tourism;

Responses
* Trained task force for emergency -treament, evacuation organisation of relocation
* Monitoring methods - seisemometer, monthy site visists
* 70 dams built to protect villages
* Prohibited resetlement around the volcano - relocationto concrete houses farther away or to Sumatra , less grouded island
* Surrounding land is only used for farming

Question 12

Effects of and Earthquake

Answer 12

• Along the conservative margin between the North American Plate and the Carribean plate boundary south of Port-au-Prince. The major earthquake was followed by several aftershocks up to a magnitude of 5.0 on the Richter scale.
• Loss of life 230,000
• Destruction of homes and schools 185,000
• Services were distroyed or disrupted
• healthcare was over worked
• Cholera as an effect of polluted drinking water

Haiti suffered so much because of the widespread poverty that left more than 80% of the population in poorly constructed, high density concrete buildings. Lack of stable goverment and medical infrastructure limited search and rescue efforts. Furthermore, the earthquake had a shallow focus, resulting in severe ground shaking, and the epicentre was located close to the densely populated capital.

Short-term responses to the earthquake included search and rescue efforts, as well as the the import of food, water and shelter from the USA and Dominican Republic. Longterm responses included reparation of three-quaters of the damaged buildings. Besides, migration was common as people moved away to stay with their families. Also, people received cash or food in exchange for public reconstruction work and the World Bank pledged $US100m to support the reconstruction and recovery.