Secondary 4 Geography Physical Geography Quiz

Answer Key - Secondary 4 Geography Quiz (Physical Geography)

Section A

1. Climate: Long-term average of weather conditions (30+ years). Weather: Short-term atmospheric conditions (daily/weekly). [3]
2. Features: Flat rocky area at base of cliff, notches. Formation: Wave-cut notch eroded at base $\rightarrow$ cliff becomes unstable $\rightarrow$ collapses $\rightarrow$ cliff retreats, leaving platform. [5]
3. Type: Destructive waves. Effect: Removes sediment (beach erosion), resulting in a gentler/flatter beach profile. [3]
4. Rotation: Earth rotates on axis $\rightarrow$ only one side faces sun at a time $\rightarrow$ day side receives solar radiation (warm), night side loses heat (cool). [4]
5. Type: Equatorial/Tropical Rainforest. Reason: High solar radiation $\rightarrow$ strong convection currents $\rightarrow$ rising air cools and condenses $\rightarrow$ heavy rainfall. [4]
6. Structure: Crust (thin, solid), Mantle (semi-molten/plastic), Outer Core (liquid iron/nickel), Inner Core (solid iron/nickel). [4]
7. Mechanism: Heat from core $\rightarrow$ magma in mantle heats up, becomes less dense $\rightarrow$ rises $\rightarrow$ cools near crust $\rightarrow$ sinks. This circular motion drags plates above. [5]
8. Evidence: (1) Jigsaw fit of continents (e.g., S. America and Africa); (2) Matching fossils/rock sequences across oceans. [4]
9. Primary: Immediate result (e.g., pyroclastic flow). Secondary: Result of primary (e.g., lahars/mudflows caused by rain on ash). [4]
10. Depth: Shallow focus $\rightarrow$ seismic waves travel shorter distance $\rightarrow$ less energy dissipated $\rightarrow$ higher intensity shaking. Deep focus $\rightarrow$ more energy lost $\rightarrow$ lower intensity. [4]

Section B

11. (a) Resistant rocks (granite) erode slowly; non-resistant rocks (limestone/clay) erode quickly due to lack of cohesion or solubility. [3] (b) Roots stabilize sediment; root systems dissipate wave energy and trap silt/sand. [3]
12. (a) Sediment transported by longshore drift/rivers $\rightarrow$ deposited where wave energy is low $\rightarrow$ accumulation forms beach. [3] (b) Shingle: Large particles, high permeability $\rightarrow$ backwash sinks into beach $\rightarrow$ more sediment stays $\rightarrow$ steeper slope. Sand: Fine particles, low permeability $\rightarrow$ strong backwash $\rightarrow$ gentler slope. [3]
13. (a) Sun heats ground $\rightarrow$ air warms and rises $\rightarrow$ cools adiabatically $\rightarrow$ condenses into clouds $\rightarrow$ heavy rain. [4] (b) Air is forced to rise over mountains (orographic lift) $\rightarrow$ cools and condenses $\rightarrow$ rain falls on windward side. [3]
14. (a) Mid-ocean ridges, rift valleys. [4] (b) Plates pull apart $\rightarrow$ magma rises to fill gap $\rightarrow$ creates volcanoes. Mid-plate volcanoes are rare (only at hotspots). [3]
15. (a) Capacity (education, infrastructure, wealth) $\rightarrow$ reduces vulnerability $\rightarrow$ lower risk even if hazard is high. [4] (b) Retrofitting buildings to be earthquake-resistant (seismic dampers). [3]

Section C

16. Framework:
    • Agree: Greenhouse gas emissions (CO2, CH4) from industry/deforestation $\rightarrow$ enhanced greenhouse effect $\rightarrow$ rapid warming.
    • Counter: Natural cycles (Milankovitch), volcanic aerosols, solar variations.
    • Conclusion: Anthropogenic factors are dominant in the recent (industrial) era. [8]
17. Framework:
    • Building Codes: Prevent collapse, save lives during event, long-term structural resilience.
    • Early Warning: Allows evacuation, short-term life-saving, doesn't prevent property damage.
    • Synthesis: Both needed; codes reduce vulnerability, warnings increase capacity. [8]
18. Framework:
    • Developed: High economic loss (infrastructure), but low death toll (better evacuation/healthcare).
    • Developing: High death toll (poor housing, lack of warnings), devastating economic blow (reliance on agriculture). [8]
19. Framework:
    • For: Unpredictability makes specific timing of response critical.
    • Against: Preparedness (drills, building codes) reduces the impact regardless of timing.
    • Conclusion: Preparedness is more logical as it lowers the baseline vulnerability. [8]
20. Framework:
    • Process: Thermal expansion of water + melting ice sheets/glaciers $\rightarrow$ higher sea levels.
    • Challenges: Saltwater intrusion into freshwater, coastal flooding, loss of habitable land/migration. [8]