Eduqas GCSE (9-1) Geography A (C111) · Spec 3.1 and 3.2
Theme 3: tectonic landscapes and hazards
Read the notes, then try the questions. Each one is marked the moment you press Check, and shows the right answer and why.
Key ideas
- In Component 1 Section B you answer on Theme 3 or Theme 4, not both. This page is for Theme 3.
- Earthquakes and volcanoes lie mostly in narrow belts along plate margins, such as the Pacific Ring of Fire.
- At a destructive margin the denser oceanic plate is pulled down (subducts), forming an ocean trench. At a constructive margin on land the crust between two faults sinks to form a rift valley.
- A hotspot is a plume of magma under the middle of a plate. The plate moves over it, so a chain of volcanoes forms, as in Hawaii.
- Shield volcanoes are broad and gently sloping with runny lava. Stratovolcanoes are steep, with ash and lava in layers and explosive eruptions.
- Poorer places are often more vulnerable, but a rich country can still suffer: Japan's 2011 Tohoku earthquake and tsunami killed 15,901 people. Hazard maps show where risk is highest, but the time and size of an earthquake cannot be predicted.
Key terms
- Subduction
- One plate sinking beneath another at a destructive margin.
- Rift valley
- A valley formed when the block of crust between two faults sinks as plates pull apart.
- Hotspot
- A plume of magma beneath the middle of a plate.
- Caldera
- A large basin formed when a volcano's summit collapses into an emptied magma chamber.
- Pyroclastic flow
- A very fast, very hot flow of gas, ash and rock.
- Vulnerability
- How likely people and places are to be harmed by a hazard.
Common mistakes
- Saying a rift valley is the gap left when plates move apart. The middle block of crust sinks between faults.
- Saying a chain of volcanoes forms where magma keeps coming up in a line. The hotspot stays still while the plate moves over it.
- Saying rich countries are not vulnerable. Density, ageing and the size of the event still create vulnerability.
- Saying hazard maps are useless because they are not exact. They show where risk is highest so that land use and evacuation routes can be planned.
Exam tip
Explain questions need a chain, not a list. For a 6-mark Explain you can reach band 3 (5-6 marks) only with thorough, linked reasoning. Use a located example, such as an eruption or earthquake you have studied, with real facts.
Free practice questions
6 questions, 10 marks. Answer, then press Check. The marking guide explains how the marks are worked out. Nothing is saved.
- Question 1 · Multiple choice[1 mark]
Which statement best explains how a chain of volcanoes, such as the Hawaiian islands, forms?
- Question 2 · Multiple choice[1 mark]
Which statement correctly describes how a rift valley forms at a constructive margin on land?
- Question 3 · Multiple choice[1 mark]
Which statement explains why an ocean trench forms along a destructive margin?
- Question 4 · Fill the gaps[2 marks]
Complete the sentences using the word bank. Use each word once. One word is not needed. A hotspot is a plume of ___ beneath the middle of a plate. As the plate moves over it, a ___ of volcanoes forms.
Word bank: chain · magma · trench
- Question 5 · Matching[4 marks]
Match each volcanic landform to its description.
- Question 6 · Put in order[1 mark]
Put these stages in the formation of a rift valley at a constructive margin in the correct order.
Use the arrows to put these in the right order, first at the top.
- 1A steep-sided rift valley is left, with magma rising along its floor
- 2The crust stretches and cracks into parallel faults
- 3Mantle convection currents pull two plates apart
- 4The block of crust between the faults slips downwards