# Exam-style Questions: Tectonics

1.

The diagram shows a cross section of a series of plate margins.

a) What are features A and B?

(2 Marks)

b) Explain why earthquakes occur at plate margins.

(4 Marks)

c) Using examples that you have studied explain why more deaths occur in LEDC's than MEDC's when earthquakes occur.

(6 Marks)

(Marks available: 12)

Answer outline and marking scheme for question: 1

a) A = Subduction zone.

B = Mid oceanic ridge.

(2 marks)

b) Give yourself marks if you mentioned the following points:

• The crust floats on the mantle.
• Convection currents in the mantle move the crust.
• The plates move together.
• The plates slide past each other.
• There is a build up of pressure.
• Finally there is a sudden release of this pressure as the plates jolt past each other.
• This sudden movement causes an earthquake.
• Earthquakes usually occur along conservative or destructive plate boundaries.

(4 marks)

c) Give yourself 1 - 2 marks if you mentioned the following points:

• Lack of money.
• Lack of emergency services.
• Buildings are not as strong.
• Lack of technology.
• Aid takes a long time to get there.

(You may not have given any case study detail at this stage).

Give yourself 3 - 4 marks if you have expanded these points and have used case studies:

• Earthquake in Turkey (1999) worse than in Japan (1995).
• Disease can spread very quickly in the unsanitary conditions left behind after the earthquake.
• Water can become contaminated.
• Insurance money rarely available for homeless so more difficult to rebuild lives.

Give yourself 5 - 6 marks if you can write in depth about the above points and relevant case studies:

• In the 1999 Turkey earthquake between 20,000 to 35,000 people were killed, in Japan (1995) in an earthquake of similar size only 5,500 died.
• Only 300 out of 1200 people rescued during the Turkey earthquake survived because of inadequate hospital facilities.
• After the earthquake there were outbreaks of cholera and typhoid, and there was no water, electricity or sewage systems.
• It took the government 48 hours to bring aid to the area.

(6 marks)

(Marks available: 12)

2. The diagram shows a cross section of a volcano.

a) What are features A and B?

(2 Marks)

b) What is an active volcano?

(1 Mark)

c) Explain why volcanoes are different shapes.

(4 marks)

d) What are the effects of a volcano?

(6 marks)

(Marks available: 13)

Answer outline and marking scheme for question: 2

a) A = Secondary vent.

B = Magma Chamber.

(2 marks)

b) A volcano that has erupted recently and is likely to erupt again.

(1 mark)

c) Give yourself 1 - 2 marks if you mentioned the following points:

• Different types of lava.
• Lava cools at different rates.
• Runny and thick lava.

Give yourself 3 - 4 marks if you expanded the points above:

• Acidic or viscous lava is thick and cools quickly therefore does not travel far.
• Thick lava creates an acid cone volcano, which has steep sides, for example, Mt Pelee.
• Basic lava is runny cools slowly and therefore runs a long way before cooling.
• Basic lava creates a gentle sided shield volcano, for example, Mt Loa in Hawaii.

(4 marks)

d) Give yourself 1 - 2 marks if you mentioned the following points, they may be in the form of a list:

• Homelessness/Death/Injury/Loss of possessions.
• Communications destroyed/Loss of wildlife (plants and animals).
• Landslides.

Give yourself 3 - 4 marks if you expanded the above points and included a case study:

• Mud flows as material from landslides mixes with water (sometimes this is melted snow).
• Lahars, which are speeding mudslides formed by ash and rain.
• 61 people were killed during the eruption of Mt St Helens.

Give yourself 5 - 6 marks if you can write in depth about the effects and show excellent knowledge of case studies:

• After the 1980 eruption of Mt St Helens no wildlife (trees or plants) survived within a 25Km blast zone.
• In 1991 Mt Pinatubo lahars covered entire villages with mud up to 10 feet deep.
• Lahars destroyed 200,000 homes and 50,000 Ha of farmland.
• Longer-term effects are the spread of diseases. In the Philippines malaria and cholera in refugee camps.

(6 marks)

(Marks available: 13)

3. a) Give an example of a fold mountain range.

(1 Mark)

b) Describe the human activities found in Fold Mountains.

(4 Marks)

c) Explain the problems of living in fold mountains.

(3 Marks)

d) What is the Richter scale?

(1 Mark)

e) State three primary effects of an earthquake.

(3 Marks)

(Marks available: 12)

Answer outline and marking scheme for question: 3

a) Himalayas/Andes/Rockies.

(1 Mark)

b) Give yourself 1-2 marks if you mention any of the following activities:

Forestry/Tourism/Farming.

Give yourself 3 - 4 marks if you can expand any of the above points:

• Farming is mainly sheep and cattle.
• In the Alps transhumance is the major form of farming where the animals are moved up to high slopes in the warm summer months but moved down to the valley floor during the winter.
• On the south facing Alpine slopes there is some farming of vines and fruit.
• Skiing, climbing and hill walking have led to the creation of new roads, restaurants and hotels.

(4 Marks)

c) Give yourself marks if you mentioned the following points:

• Steep slopes are difficult to build on.
• Roads tend to be windy and not large enough for an increasing population.
• Climate is cold and wet so farming is difficult.
• Avalanches are a constant threat.

(3 Marks)

d) A scale that measures the strength of earthquakes.

(1 Mark)

e) Give yourself marks if you mentioned the following points:

• Bridges collapsing/Communication lines destroyed.
• Houses collapse/death/injury.

(3 marks)

(Marks available: 12)

4. a) Where are most earthquakes and volcanoes found?

(2 Mark)

b) What can be done to reduce the impact of volcanoes?

(3 Mark)

c) What is a dormant volcano?

(1 Mark)

d) Why do people choose to live in volcanic areas?

(6 Marks)

(Marks available: 12)

Answer outline and marking scheme for question: 4

a) Give yourself marks if you mentioned the following points:

• Along plate boundaries.
• Pacific Ring of Fire.
• West coast of America.
• Along the mid Atlantic Ridge.

(2 marks)

b) Give yourself marks if you mentioned the following points:

• Evacuation/200,000 people evacuated from the area surrounding Mt Pinatubo.
• Spraying lava with water.
• Scientific prediction able to warn before disasters.

(3 marks)

c) A volcano that has not erupted for 2000 years.

(1 mark)

d) Give yourself 1 - 2 marks if you mentioned the following points:

• Fertile soil/Tourism/Minerals/Power/Communications.

Give yourself 3 - 4 marks if you expanded the above points:

• Ash and lava create fertile soil for farming.
• The heat in the rocks can be harness to provide cheep geothermal energy for residents.
• Volcanoes create a wealth of important minerals.

Give yourself 5 - 6 marks if you can write in depth about why people live near volcanoes and have included case studies:

• The slopes of Mt Pinatubo are fertile and provide well-cultivated paddy fields.
• Volcanic island like Iceland are often in the middle of large expanses of water like the Atlantic so are excellent stopping off points for long haul flights.

(6 marks)

(Marks available: 12)