Earthquake Notes

Earthquakes

Richter Scale

• Each level is 10 times stronger than the previous level.

What is an Earthquake?

• Sudden, violent shaking of the ground causing cracks and building collapse.
• Measured by the Richter scale.
• Earthquakes between 6 and 9 cause significant damage.

Causes of Earthquakes

• Volcanic eruptions.
• Movements of tectonic plates.
• Faults: Breaks in the Earth’s crust where plates meet.
• The Ring of Fire: Earthquake zone around the Pacific Ocean (90% of world’s earthquakes).

How Earthquakes Happen

• Plates collide or edges get stuck.
• Stress builds up along fault lines.
• Rocks fracture, releasing energy as seismic waves.
• Hypocentre: Point within the Earth where the earthquake starts.
• Epicentre: Point on the surface above the hypocentre.

Effects of Earthquakes

• Injuries and death.
• Diseases due to destroyed water supplies.
• Displacement: Loss of homes.
• Damage to infrastructure: Roads, railways, pipelines, etc.
• Flooding from broken dams and pipes.
• Fires from broken wires and gas leaks.
• Tsunamis: Major damage to settlements and environment.
• Economic impact: Damage to the economy and trade.
• Medical: Pressure on hospitals and rescue services.

Risk Factors

• Building standards.
• Population density.
• Services and support.
• Level of preparedness.

Preparing for Earthquakes

• Early warning systems.
• Disaster management plans and drills.
• Building standards.
• Family plans.

Responding to Earthquakes

• If in a building:
  • Drop, cover, and hold on.
  • Wait until shaking stops.
  • Check for fires.
  • Use stairs, not the lift.
• If outside:
  • Move away from buildings, trees, poles, and powerlines.
  • Crouch down and cover your head.
• If in a vehicle:
  • Stop safely and stay in the vehicle.
  • Drive carefully after the earthquake.