Physical geography · GCSE Geography
Natural hazards
Tectonic and weather hazards: why they happen, why death tolls differ, and how places prepare, respond and recover.
The same plate margin, two countries — wealth decides the death toll.
The important bits
What you need to know
- 1
A natural hazard is a natural event that threatens people. It becomes a disaster when lives, livelihoods or infrastructure are overwhelmed. Vulnerability (poverty, housing, governance) matters as much as magnitude.
- 2
Earthquakes and volcanoes cluster at plate margins. Constructive margins (Iceland) create volcanoes and rifts; destructive margins (Japan, Andes) create explosive volcanoes, fold mountains and deep earthquakes; conservative margins (San Andreas) create earthquakes without volcanism.
- 3
At destructive margins, denser oceanic plate subducts, melts, and magma rises; friction causes earthquakes. At conservative margins, plates stick then slip. Learn one diagram you can redraw under pressure.
- 4
Named tectonic examples must include contrast: e.g. Tohoku, Japan 2011 (HIC, magnitude 9.0, tsunami, Fukushima, strong building codes, still huge economic cost) versus Haiti 2010 (LIC, magnitude 7.0, catastrophic death toll, weak buildings, slow recovery). Magnitude alone does not explain impact.
- 5
Tropical storms form over warm oceans (about 27°C+) between roughly 5° and 20° latitude, where the Coriolis effect spins the system. They need moisture and low wind shear. Once over land they weaken. Distribution is not random.
- 6
Typhoon Haiyan (Philippines, 2013) is a standard NEE/LIC weather-hazard case: storm surge, thousands dead, aid bottlenecks, later rebuilding and mangrove discussion. Compare with a UK extreme-weather event (Beast from the East 2018, or a named flood) for HIC contrast.
- 7
Management is a cycle: monitoring, prediction, protection (sea walls, building codes, shelters) and planning (land use, drills, insurance). HICs do more of all four; LICs often rely on aid after the event.
- 8
Climate change is loading the dice for some weather hazards (more intense storms, heat, some flood patterns) while tectonic hazards remain independent of greenhouse gases. Keep those systems separate in your head.
Go deeper
Why Haiti 2010 killed so many more than Chile 2010
Both earthquakes struck in 2010. Chile’s Maule quake was larger (about magnitude 8.8) yet killed far fewer people than Haiti’s magnitude 7.0 disaster in Port-au-Prince. Chile sits on a well-known destructive margin, with building codes, a long history of drills and a functioning emergency state. Haiti’s capital had dense informal housing, limited enforcement, a shallow epicentre near the city, and a government already weak before the event. Secondary hazards — aftershocks, disease in camps, delayed aid — multiplied deaths. The geographical lesson is brutal and examinable: physical magnitude is not social impact. Always write a hazard answer as hazard + vulnerability + capacity to respond.
Go deeper
Plate margins without waffle
You need mechanisms, not labels. Constructive: plates diverge, magma fills the gap, gentle-shield volcanoes and earthquakes as crust cracks. Destructive: ocean plate subducts, sediments and water lower melting point, sticky magma, composite volcanoes, trenches, fold mountains, violent quakes. Conservative: plates scrape, no magma, elastic strain released as earthquakes. Hotspots (Hawaii) are the exception that proves the rule — volcanism away from a margin. In 4- and 6-mark process questions, a labelled sequence beats adjectives like “huge” and “dangerous”. Save named places for effects and management, not for decorating a margin you cannot explain.
Go deeper
Haiyan and the storm-surge problem
Typhoon Haiyan (Yolanda) crossed the central Philippines in November 2013 as one of the strongest landfalling storms recorded. Wind damage was severe; the killer in Tacloban was storm surge funnelled into a shallow bay, drowning people who had sheltered in low buildings. Poverty, coastal density and deforestation of mangroves increased exposure. The government issued warnings, but power, roads and airport damage slowed aid; international response then faced logistics chaos. Longer-term management includes stronger building, mangrove restoration and evacuation culture. Use Haiyan to show that prediction without protected places still fails, and that LICs can have excellent local knowledge yet lack the capital to build out of the surge zone.
See the idea in action
A 9-mark question asks why the effects of tectonic hazards vary. Thesis: physical factors (magnitude, depth, distance, secondary tsunami) set the energy; human factors decide deaths and recovery. Evidence: Japan 2011 versus Haiti 2010, or Nepal 2015 versus Chile. Develop: building standards, time of day, GDP, insurance, aid quality. Conclusion: two places can share a margin and not share a death toll because development geography sits on top of plate tectonics.
Exam technique
Turn knowledge into marks
Every hazard paragraph needs a named place and a number if you have one (magnitude, deaths, cost). “It was bad” is not geography.
Common mistakes
Do not give these marks away
- 01
Mixing up constructive and destructive margins, or putting volcanoes on the San Andreas Fault.
- 02
Explaining impacts with magnitude only and forgetting wealth, governance and building quality.
- 03
Writing a generic “they should build a sea wall” without saying whether the place is LIC or HIC, coastal or inland.
Why can a smaller earthquake kill more people than a larger one?
ABecause magnitude scales are random
BBecause vulnerability — building quality, poverty, time of day and governance — can outweigh magnitude
CBecause earthquakes only kill people in HICs
DBecause conservative margins always produce higher death tolls
Show the answer
Because vulnerability — building quality, poverty, time of day and governance — can outweigh magnitude. Haiti 2010 versus Chile 2010 is the textbook contrast. Energy released is only one variable. Where people live and how well the state prepares decides whether a quake is a disaster.
Quick questions
If this is the bit you searched
Do volcanoes occur at all plate margins?
No. Conservative margins generate earthquakes without volcanism because crust is neither created nor destroyed. Volcanoes are typical at constructive and destructive margins, plus some hotspots.
What is the difference between a hurricane, typhoon and cyclone?
They are the same type of tropical storm in different ocean basins: hurricane in the Atlantic and NE Pacific, typhoon in the NW Pacific, cyclone in the Indian Ocean and South Pacific.