Option D • Section 2
Geophysical Hazard Risks
Distribution, magnitude, frequency, recurrence and the geographic factors turning hazards into disasters.
The spatial distribution and impacts of geophysical hazards
Distribution of geophysical hazards
Earthquakes and volcanoes cluster around tectonic margins; mass movements reflect slope, triggers and exposure.
Enquiry 1 — From pattern to process
Map earthquakes, volcanoes and major mass movements. Describe clusters and anomalies, then explain them using tectonic setting, topography, climate and human modification.
Magnitude, frequency and recurrence
Large events are rarer; recurrence intervals describe probability, not a timetable.
Earthquake magnitude is logarithmic, while intensity records observed effects. Event databases are shaped by changing detection, reporting, exposure and definitions, so trends require careful interpretation.
Enquiry 2 — Has the world become safer?
Compare event counts, mortality and exposure through time. Identify data limitations, then judge whether falling death rates indicate lower risk or improved preparedness.
Human risk factors
Disaster risk emerges from hazard, exposure, vulnerability and coping capacity.
Income alone does not determine vulnerability. Age, health, gender, housing, land tenure, governance, education, risk perception, social networks and access to warnings all shape outcomes within and between places.
Enquiry 3 — Vulnerability ranking
Rank six hypothetical communities using exposure, sensitivity and coping capacity. Defend the ranking and identify the single intervention that would reduce risk most.
Factors affecting event impacts
Location, depth, geology, relief, accessibility, population density and time of day modify impacts.
Enquiry 4 — Same hazard, different place
Apply one identical hazard profile to an urban core, informal settlement, isolated rural district and wealthy suburb. Predict contrasting primary and secondary impacts, response speed and recovery.