Theories
Who proposed the theory of continental drift?
Alfred Wegener (1912)
What is the point inside the Earth where an earthquake starts called?
Focus (hypocentre)
What is a volcano?
An opening in the Earth’s crust where magma, gas, and ash escape to the surface.
What is the main difference between earthquakes and volcanoes?
Earthquakes = sudden ground shaking; Volcanoes = magma and gases erupting from the crust.
What is the first stage of managing hazards?
Prediction & monitoring – use sensors, GPS, and seismometers to detect activity.
Name the three main types of plate boundaries.
Convergent (destructive), Divergent (constructive), and Transform (conservative).
What is the point on the surface directly above the focus?
Epicentre
What type of plate boundary usually forms volcanoes?
Destructive (subduction) and constructive (divergent) boundaries.
Give one social and one economic impact of a tectonic hazard.
Social: loss of lives/homes. Economic: costly rebuilding, loss of tourism or industry.
Name one way buildings can be made earthquake-resistant.
Cross-bracing, shock absorbers, base isolators, and flexible frames reduce shaking damage.
Give one piece of evidence for continental drift.
Coastlines of Africa and South America fit together like puzzle pieces; similar fossils and rock types found on both sides of the Atlantic.
Which instrument measures earthquakes?
Seismograph – records ground vibrations on a seismogram.
Name and describe two main types of volcanoes.
Shield: wide, gentle slopes, runny lava (e.g. Hawaii). Composite: steep-sided, layers of ash + lava, explosive (e.g. Mount Fuji)
Why are LICs often more affected by tectonic hazards?
Weaker infrastructure, poor emergency response, lack of prediction or insurance.
How can education reduce hazard impacts?
Drills, awareness campaigns, and evacuation training help people respond quickly and safely.
What causes plates to move?
Convection currents in the mantle created by heat from the Earth’s core move the plates above them.
How are earthquakes measured?
Magnitude: Richter scale (energy released). Intensity: Mercalli scale (damage caused).
What is a pyroclastic flow?
A fast-moving, extremely hot cloud of gas, ash, and rock that rushes down a volcano’s slope
How can tectonic hazards trigger secondary hazards?
Earthquakes → tsunamis & landslides; volcanoes → lahars and mudflows
Give one example of short-term and one long-term response to a tectonic disaster.
Short-term: rescue, food, shelter. Long-term: rebuilding homes, improving infrastructure and planning.
How did seafloor spreading support Wegener’s idea?
New crust forms at mid-ocean ridges as magma rises; older crust moves outward — proved by symmetrical magnetic patterns on the ocean floor.
Describe two short-term and two long-term effects of earthquakes.
Short-term: collapsed buildings, injuries. Long-term: homelessness, economic loss, infrastructure damage.
Explain why volcanic eruptions differ in explosiveness.
Depends on magma composition – silica-rich magma is thick and traps gas → explosive; basaltic magma is runny → gentle eruptions.
“Tectonic hazards are natural events, but disasters are human.” Explain.
Hazards only become disasters when they affect vulnerable people — preparation, population density, and poverty increase risk.
Evaluate why prediction and preparedness are more effective than response.
Prevention saves more lives and costs less; responses often come too late and depend on resources – preparedness builds resilience before hazards strike