🌍 GCSE Geography

Tectonic Hazards

Plate Tectonics

• Earth's crust is divided into tectonic plates floating on the semi-molten mantle (asthenosphere)
• Convection currents in the mantle drive plate movement
• Convergent boundary: plates collide → subduction zone → volcanoes, fold mountains, earthquakes
• Divergent boundary: plates move apart → new crust formed (e.g. Mid-Atlantic Ridge)
• Conservative boundary: plates slide past each other → earthquakes (e.g. San Andreas Fault)

Earthquakes

• Focus: point underground where earthquake starts; Epicentre: point directly above on the surface
• Measured on the Richter scale (logarithmic) or Moment Magnitude Scale
• Primary effects: immediate — buildings collapse, people killed
• Secondary effects: longer-term — fires from broken gas pipes, disease, tsunami
• LICs face greater impacts due to poor construction, limited emergency services, and less preparedness

Volcanoes

• Shield volcanoes: gentle slopes, runny lava, less explosive (divergent boundaries)
• Composite volcanoes: steep sides, viscous lava, explosive (convergent boundaries)
• Primary hazards: lava, pyroclastic flows, tephra (ash/rock); Secondary: lahars (mudflows), acid rain

River Landscapes

River Processes

• Erosion types: hydraulic action, abrasion (corrasion), attrition, corrosion (solution)
• Transportation types: traction, saltation, suspension, solution
• Deposition: occurs when energy decreases (e.g. inside of bend, at river mouth)

Upper Course

• Steep gradient, fast flow, vertical erosion
• Features: V-shaped valleys, interlocking spurs, waterfalls, gorges

Middle Course

• More lateral erosion, meanders develop
• Features: meanders, river cliffs (outside bend), slip-off slopes (inside bend), floodplain

Lower Course

• Low gradient, slow velocity, mainly deposition
• Features: wide floodplain, oxbow lakes, deltas, levées

Flooding & Management

• Causes: heavy/prolonged rain, impermeable surfaces (urbanisation), deforestation, snowmelt
• Hard engineering: dams, embankments, channel straightening
• Soft engineering: floodplain zoning, afforestation, river restoration

Coastal Landscapes

Coastal Erosion

• Processes: hydraulic action, abrasion, attrition, corrosion
• Wave cut platform → wave cut notch → cliff retreat
• Features: headlands and bays, caves, arches, stacks, stumps

Coastal Deposition

• Longshore drift: waves approach at angle → swash moves sediment at angle → backwash pulls straight back
• Features: beaches, spits (curved at end due to wind direction change), bars, tombolos

Coastal Management

• Hard engineering: sea walls, rock armour (rip rap), groynes, revetments
• Soft engineering: beach nourishment, managed retreat, dune stabilisation
• Managed retreat: allow low-value land to flood; more sustainable long-term

Weather, Climate & Climate Change

UK Weather

• UK climate: cool, temperate, and wet — influenced by the Atlantic Ocean and prevailing south-westerly winds
• Depressions (low pressure): bring cloud, rain, and wind from the west
• Anticyclones (high pressure): bring dry, clear weather; cold in winter, hot in summer

Tropical Storms (Hurricanes/Typhoons)

• Form over warm ocean water (26°C+) between 5°–20° north/south of equator
• Structure: eye (calm), eye wall (strongest winds/rain), spiral rainbands
• Primary effects: strong winds destroy buildings; storm surge; flooding
• Secondary effects: disease, homelessness, economic damage

Climate Change

• Evidence: rising global temperatures, retreating glaciers, rising sea levels, more extreme weather
• Causes: enhanced greenhouse effect — CO₂, methane, nitrous oxide trap heat
• Natural causes: Milankovitch cycles, volcanic eruptions, solar output variation
• Mitigation: reduce emissions (renewable energy, electric vehicles, carbon capture)
• Adaptation: flood defences, drought-resistant crops, changes to farming practices

Urban Issues & Challenges

Urbanisation

• More than 50% of the world's population now lives in cities
• Urbanisation fastest in LICs/NEEs due to rural-urban migration (push: lack of jobs/services; pull: employment, better services)
• Megacities: cities with over 10 million population (e.g. Mumbai, Tokyo, New York)

Urban Issues in LICs (e.g. Rio de Janeiro)

• Squatter settlements (favelas): informal housing — poor sanitation, crime, unemployment
• Solutions: upgrading programmes, self-help schemes, site and service schemes

Urban Issues in HICs (e.g. London)

• Challenges: unequal distribution of wealth, housing shortage, traffic congestion, urban sprawl
• Regeneration: brownfield site development, improving deprived areas (e.g. Olympic Park, Stratford)
• Sustainable urban living: renewable energy, cycling infrastructure, green spaces

The Changing Economic World

Measuring Development

• GDP (Gross Domestic Product): total value of goods produced per year
• GNI per capita: average income per person
• HDI (Human Development Index): combines income, education, and life expectancy (0–1 scale)
• Limitations: averages hide inequalities within countries

Causes of Uneven Development

• Historical: colonialism left many countries without infrastructure or skills
• Physical: landlocked, natural disasters, poor soils, tropical disease
• Economic: debt repayments, unfair trade, dependency on primary products

Reducing the Development Gap

• Aid: short-term (emergency) and long-term (development aid)
• Fair Trade: farmers get a guaranteed fair price
• Debt relief: cancelling debts allows governments to invest in services
• Microfinance: small loans to individuals to start businesses
• Tourism: can bring income and jobs, but profits often leave the country (leakage)

Resource Management

• Resource security: having enough food, water, and energy to meet needs
• Water insecurity: physical scarcity (too little rain) or economic scarcity (lack of infrastructure)
• Increasing water supply: dams, desalination, water transfer schemes, groundwater extraction
• Food insecurity: affects majority of LIC populations; causes include poverty, conflict, climate change
• Energy mix: most countries use a combination of fossil fuels, nuclear, and renewables
• Energy security: UK increasingly dependent on imports; shifting to renewables reduces dependence

Fieldwork & Investigation

You will need to discuss your own fieldwork investigations in the exam. Be able to explain:

• The question or hypothesis you were investigating
• Your data collection methods and why you chose them
• Primary data (collected yourself) vs secondary data (from existing sources)
• Potential limitations and sources of error
• How you presented data (graphs, maps, photographs)
• Your conclusions and how they relate to the hypothesis

Map Skills

• Grid references: 4-figure (square) and 6-figure (point) — "along the corridor, up the stairs"
• Contour lines: close together = steep; far apart = gentle slope; concentric circles = hill/valley
• Scale: 1:25,000 means 1 cm = 250 m (OS Explorer maps); 1:50,000 means 1 cm = 500 m
• Aspect: direction a slope faces
• Cross-sections: draw a line on the map and record contour heights to create a profile
• Atlas skills: latitude/longitude, use of key and index