O Level Geography Physical Geography Quiz

O-Level Geography Quiz - Physical Geography (Answer Key)

Total Marks: 50

Section A: Plate Tectonics

1. (a) Asthenosphere / Upper Mantle [1] (b) Radioactive decay (of elements in the core/mantle) / Residual heat from Earth's formation [1]

2. A plate boundary is the zone where two tectonic plates meet/interact. [1] It is a region of geological activity such as earthquakes and volcanoes. [1]

3. At constructive boundaries, plates move apart/diverge. [1] This creates a gap allowing magma from the mantle to rise to the surface. [1] As pressure decreases, the magma erupts as lava, forming volcanoes/new crust. [1]

4. Earthquakes are concentrated along plate boundaries. [1] Specifically, they form a ring around the Pacific Ocean (Ring of Fire) and a belt across Eurasia (Alpine-Himalayan). [1] (Accept: They are not evenly distributed; they are linear in pattern).

5. Example: 2011 Tohoku Earthquake, Japan. Loss of life/injury due to building collapse or tsunami. [1] Displacement of people/homelessness. [1] Damage to infrastructure (roads/hospitals) disrupts emergency services and daily life. [1] (Award marks for any valid named example and linked social impact).

6. Agree: Higher magnitude releases more energy, causing stronger ground shaking and wider area of damage. [1] Disagree/Other Factors: Depth of focus (shallow quakes cause more damage). [1] Level of development/preparedness (building codes in MEDCs reduce damage). [1] Population density (remote areas have less damage despite high magnitude). [1] (Award up to 4 marks for balanced argument with examples).

7. Primary effects: Immediate results of the eruption (e.g., lava flows, ash fall, pyroclastic flows). [1] Secondary effects: Consequences that happen later or as a result of primary effects (e.g., mudflows/lahars, disease, famine, economic loss). [1]

Section B: Weather and Climate

8. Barometer (or Aneroid Barometer) [1]

9. Weather is the short-term state of the atmosphere (hours/days) including temperature, rain, wind. [1] Climate is the average weather conditions over a long period (usually 30+ years) in a specific area. [1]

10. (a) High temperatures year-round / Little annual range / Average approx 27°C. [1] (b) Equatorial / Tropical Rainforest Climate. [1]

11. Places near the equator (low latitude) receive direct/vertical sunlight, concentrating heat over a smaller area. [1] Places at high latitudes receive slanted/oblique sunlight, spreading heat over a larger area. [1] Sunlight at high latitudes travels through more atmosphere, losing more heat via scattering/absorption. [1]

12. Moist air is forced to rise over a mountain barrier. [1] As it rises, it expands and cools. [1] When it reaches dew point, water vapour condenses into clouds. [1] Heavy rainfall occurs on the windward side; dry air descends on the leeward side. [1]

13.

1. Concrete/asphalt absorbs and stores more heat than vegetation/soil. [1]
2. Lack of vegetation reduces cooling from evapotranspiration. [1] (Accept: Waste heat from vehicles/industry; Canyon effect trapping heat).

14. (a) Range = Highest (25) - Lowest (12) = 13 km/h. [1] (b) Increased solar heating causes convection currents/air pressure differences. [1] (Accept: Sea breeze development if coastal context implied).

Section C: Climate Change and Action

15. The process where greenhouse gases (like CO2 and Methane) trap outgoing longwave radiation (heat) in the atmosphere. [1] Human activities have increased the concentration of these gases, enhancing the natural effect and raising global temperatures. [1]

16.

1. Burning of fossil fuels (coal, oil, gas) for energy/transport. [1]
2. Deforestation (burning trees releases stored carbon; fewer trees to absorb CO2). [1] (Accept: Agriculture/livestock farming for methane).

17. Melting of ice sheets/glaciers. [1] This leads to rising sea levels. [1] Which causes loss of habitat for polar bears/penguins and coastal flooding elsewhere. [1] (Accept: Ocean acidification affecting marine life).

18. Mitigation: Actions to reduce the causes of climate change (e.g., reducing emissions). [1] Adaptation: Actions to adjust to the impacts of climate change (e.g., building sea walls). [1]

19. Agree: Climate change is global; emissions in one country affect others. [1] Agreements like the Paris Accord set shared targets. [1] Disagree/Limitations: Countries have different economic priorities (LEDCs need growth). [1] Enforcement is difficult; some countries withdraw or ignore targets. [1] (Award up to 4 marks for evaluation).

20. Effective: Trees absorb CO2 during photosynthesis, acting as carbon sinks. [1] They also provide other benefits like preventing soil erosion. [1] Limitations: Takes decades to grow; land availability is limited; trees can burn/release carbon if forests catch fire. [1] (Award up to 3 marks for evaluation).