Tectonic Landscapes

Question 1

What are the economic reasons for why people might live in hazard areas?

Answer 1

☼ Volcanic soils are especially fertile. e.g. the world’s best coffee is grown on volcanic soil in Columbia.

☼ Minerals such as tin, silver, gold, copper and diamonds can be found in volcanic rocks → more money made

☼ In Iceland, volcanoes provide very cheap geothermal energy → so inexpensive that in winter, pavements are heated.

☼ Some areas are popular tourist areas and provide jobs for the locals.

Question 2

What are the social reasons for why people might live in hazard areas?

Answer 2

☺ A lot of poor people, particularly in low income countries, don’t move because they cannot afford to. Some do not want to leave their family and friends, or heritage.

☺ Many people who live close to mount Merapi in Indonesia worship spirits and believe that the spirits watch over the peak and will warn them about an eruption.

☺ People believe that the chance of the volcano erupting is very low, so they think living there is worth the risk as it has been dormant for hundreds of years.

☺ Some people feel safe because new technology has meant buildings are earthquake-proof.

Question 3

What are the environmental reasons for why people might live in hazard areas?

Answer 3

♥ Some volcanoes are popular tourist areas. e.g. Mount Etna in Sicily attracts 1000s of tourists, and this gives locals more jobs.

♥ People buy houses in areas for their beauty, and believe it is worth the risk of earthquakes for the setting and views they have.

Question 4

What happens at convergent plate boundary?

Answer 4

Two continental plates:

• Collision plate boundary
• Made from similar, low density rock so neither is pushed under. Instead, they push together and are forced upwards, along with any soil material on the ground.
• Violent earthquakes form, but no volcanoes
• fold mountains are created
• e.g. Himalayas.

Oceanic and continental plates:

• When they move towards one another and meet, the denser oceanic plate is forced under the lighter continental plate. This is called subduction.
• When subduction occurs, an ocean trench forms (deep underwater valley where plates are pushing into each other)
• Oceanic plate melts into mantle layer, and additional magma forces its way up under immense pressure and a volcano forms → violent eruptions and strong earthquakes.
• Fold mountains also found here as continental crust rises as oceanic pushes into it.
• e.g. South American plate meets Nazca Plate.

Question 5

Explain how earthquakes occur.

Answer 5

Tectonic plates move because of convection currents beneath them and the lava rises and cools.

Plates slide past each other and they get stuck, but they keep moving because of the convection currents.

Under immense pressure, the plates snap, creating tremors.

Question 6

What are the characteristics of earthquakes?

Answer 6

• Violent shaking of the earth’s crust
• Caused by sudden release of enourmous stresses, leading to the crust snapping
• The point at which snapping occurs is called the focus
• The point on the ground surface immediately above the focus is called the epicentre - where greatest damage occurs.

Question 7

How can you reduce the effects of earthquakes through design and education?

Answer 7

The three P’s:

• Prediction: The use science/technology to monitor tectonic activity. e.g. GPS uses satellites and radio waves to predict tectonic activity. Seisometers predict activity by measuring ground vibrations
• Preparation: Creating emergency plans to implement once the disaster has struck
• Planning: Earthquake proofing buildings in urban areas to reduce damage, injury and death. See image.