Natural Hazards (OCR GCSE Geography A (Geographical Themes)): Revision Notes

1.1.1 Natural Hazards

What is a Natural Hazard?

1. A natural hazard is a natural process which could cause death, injury, or disruption to humans, or destroy property and possessions.
2. A natural disaster is an event that has actually happened.

What are the Main Types of Hazards?

• Geological Hazards:
  • Caused by land and tectonic processes.
  • Examples: volcanoes, earthquakes, landslides.
• Meteorological Hazards:
  • Caused by weather and climate.

What Affects a Country's Ability to Cope?

• Vulnerability:
  1. The more people in areas exposed to natural hazards, the greater the probability they will be affected.
  2. Example: People living at the base of a volcano in Naples, Italy are vulnerable to eruptions.
• Capacity to Cope: 3. Natural hazards have to affect human activities to count as a hazard. The better a population can cope with an extreme event, the lower the threat. 4. Example: High-Income Countries (HICs) are better able to cope with earthquakes as they can build earthquake-proof buildings and repair damage afterwards.

Hazard Risk

Techtonic Hazards

• The probability that a natural hazard occurs.
• Three main factors affecting risk: 5. Type: The hazard risk from some hazards is greater than others (e.g., tropical storms can be predicted but earthquakes can't). 6. Frequency: Some natural disasters occur more often than others (e.g., flooding). 7. Magnitude: More severe natural hazards cause greater effects than less severe events (e.g., a magnitude 5 earthquake compared to a magnitude 8).

Tectonic Plates

1. Structure:

• The inner core is solid and outer liquid.
• Around the core is the mantle - semi-molten rock moving slowly.
• The outer layer is the crust, divided into slabs called tectonic plates.

2. Types of Plates:

• Plates can be continental or oceanic.
• The meeting point is called a plate boundary/margin.

3. Movement:

• Plates move due to convection currents in the mantle.