past paper questions

Question 1

‘Risk from large scale atmospheric disturbances can be completely removed by effective preparation of people and property.’
How far do you agree with this view?

Answer 1

Large scale atmospheric disturbances are tropical cyclones, hurricanes and typhoons. The hazards associated with them are storm surges, coastal
flooding, intense rainfall and high winds. The risks are associated with these hazards but will also be conditioned by the local topography, geology for mass movement caused by the intense rainfall, and flooding if there are major rivers. These risks need assessing with respect to preparation of people and property. This will include any coastal defences, building design for high winds and river defences for flooding. Prediction and monitoring are also relevant. The most probable assessment is that the risks cannot be completely removed but that they can be reduced.

Question 2

Assess the extent to which prediction, hazard mapping and preparedness can reduce the impacts of mass movements on lives and property.

Answer 2

There needs to be specific reference to a variety of mass movements. Prediction of mass movement is difficult but an understanding of the nature of the mass movements chosen for discussion and the nature of the most susceptible rocks and soils will enable some prediction to be made. Thus mudflows, which require an input of water and specific earthquake materials, might be related to intense rainfall. This also forms the basis of much hazard mapping. Preparedness could be related to planning controls in association with the hazard mapping and preventative techniques.

Effectiveness of these techniques should focus on reduction of impacts on lives and property. Impacts on lives and property include residential, commercial, public buildings, and infrastructure such as transportation, water, energy, and communication systems which may be damaged or destroyed.

Question 3

Describe the global distribution of volcanoes

Answer 3

Candidates may identify that globally:
* Volcanoes are mainly linear in their distribution
* Uneven global distribution
* Widespread global distribution
More specific points:
* Pacific Ring of Fire
* Many are along the edges of continental landmasses, e.g. western edge of South America
* Others are mid-oceanic, e.g. mid-Atlantic
* A few are in continental interiors, e.g. central Asia
* A few are more clustered, e.g. Iceland
* East Africa (Rift Valley) – linear
* Continental interiors where volcanoes do not occur, e.g. Australia,
South America

Question 4

Explain why volcanoes are not found at all types of tectonic plate boundary

Answer 4

• Volcanoes are formed by rising magma
• This may be due to the rising limbs of convection currents (divergent boundaries)
• Or the melting of subducted plate edge material (convergent boundaries)
• Neither of these situations arise at collision boundaries
• Or conservative (transform) boundaries

Question 5

Assess the relative significance of the hazards resulting from small-scale atmospheric disturbances
(tornadoes).

Answer 5

• Significance may be assessed in terms of frequency,
  magnitude, causal role, impact, vulnerability
  Hazards include:
• Intense precipitation – rain and hail
• High winds
• Pressure imbalances

Question 6

‘Earthquake hazards cannot be prepared for successfully.’
How far do you agree?

Answer 6

• evaluation of the various preparation strategies, which might include both those that have been attempted and other possible alternatives
• determined by the primary (ground shaking) and secondary hazards (building collapse, landslides, liquefaction, tsunami)
• Earthquake-resistant building design
• Monitoring – for radon gas emissions, ground changes, precursive seismic activity, changes in magnetism
• Hazard mapping
• Risk assessment
• Evacuation drills
• Emergency service provision
  Evaluation may consider:
• Effectiveness in saving lives and protecting property
• Sustainability
• Cost-benefit analysis