Eduqas A-Level Geography A110QS
Coastal LandscapesLandscape
Glaciated LandscapesLandscape
Changing Places
Water and Carbon Cycles
Global Migration
Global Governance of the Oceans
Tectonic Hazards
EcosystemsContemporary theme
Economic Growth and Challenge: IndiaContemporary theme
Economic Growth and Challenge: ChinaContemporary theme
Development in an African ContextContemporary theme
Energy Challenges and DilemmasContemporary theme
Weather and ClimateContemporary theme
Geographical Skills
Tectonic Hazards
Ground shaking, liquefaction and landslides
- 2 things to know
- Component 3 Section A
Overview
How ground shaking damages buildings, peak ground acceleration and why soft sediment increases earthquake damage.
What you need to know
Answer each one before you reveal it.
What is peak ground acceleration?
Questions from this subtopic
Each one with the model answer underneath.
- 1
Explain how ground shaking damages buildings.
Model answer
Repeated horizontal acceleration puts shear stress on walls and joints designed only for vertical loads. Failure of a lower storey brings the floors above down on top of it.
- 2
What is peak ground acceleration?
Model answer
Peak ground acceleration is the greatest acceleration of the ground during shaking, usually given as a fraction of gravity. Values above 0.3 g typically cause serious damage to ordinary buildings.
- 3
What is resonance, and why does it matter in an earthquake?
Model answer
Resonance occurs when the shaking frequency matches a building's natural frequency, so the swaying grows. Buildings of one particular height can be destroyed while their neighbours survive.
- 4
Explain why soft sediment increases earthquake damage.
Model answer
Loose sediment amplifies the amplitude of seismic waves compared with solid bedrock. Mexico City's lake-bed clays amplified the 1985 earthquake, whose epicentre lay around 350 km away.
- 5
Define liquefaction.
Model answer
Liquefaction occurs when shaking causes saturated, loosely packed sand to behave as a fluid. Pore water pressure rises and the grains lose contact with one another.
- 6
What are the consequences of liquefaction?
Model answer
Buildings tilt or sink because the ground loses its bearing strength. Buried pipes and tanks float upwards, and silt is ejected at the surface as sand volcanoes.
Other ways to work this
The same content, four other ways.
What is inside Levo
Six ways to work the same material.
Every question in Tectonic Hazards, on a schedule.
Attempt a question from memory, write the correct version, then attempt it again. Levo records the jump between your first attempt and your last, and brings each question back on the day you are due to forget it.
Or £46 a year, about £3.83 a month. Cancel anytime.