GCSE Geography Study Guide – Natural Hazards

GCSE Geography Natural Hazards Study Guide by AI

What are Natural Hazards?

A natural hazard is defined as “a natural process which could cause death, injury or disruption to humans, or destroy property and possessions”  These hazards can be classified into two main categories:

1. Geological Hazards: Caused by land and tectonic processes, such as volcanoes and earthquakes.
2. Meteorological Hazards: Caused by weather and climate, including storms, heatwaves, and cold spells.

The Impact of Natural Hazards

The impact of a hazard, or “hazard risk”, depends on:

• Vulnerability: Populations in areas exposed to hazards, particularly dense urban areas, are more vulnerable. For example, “a city at the base of a volcano (like Naples, Italy) is very vulnerable to volcanic eruptions” .
• Capacity to Cope: Wealthier populations can generally cope better with hazard events, having resources for mitigation and recovery. This includes infrastructure such as “flood defences” and the financial capacity to “evacuate people” .

Tectonic Hazards: Earthquakes and Volcanoes

The Earth’s surface is made of tectonic plates, constantly shifting and interacting . This movement generates:

• Volcanoes: These form at destructive and constructive plate margins. At destructive margins, denser oceanic plates sink, creating magma that rises and erupts. “Sometimes the magma rises through cracks in the crust called vents… forming a volcano” .

• Earthquakes: Occur at all three types of plate margins due to the tension and pressure built up by plate movement. “These vibrations are the earthquake. The waves are spread out from the focus – the point where the earthquake starts” .

Living with Tectonic Hazards

Many populations live in tectonically active areas, often drawn by:

• Economic opportunities: “The minerals from volcanic ash make soil around volcano very fertile, attracting farmers”. Volcanoes also attract tourism .
• Lack of alternatives: Some people cannot afford to move or are unaware of the risks.

Managing Tectonic Hazards

Strategies for reducing the impact of tectonic hazards include:

• Monitoring: Using seismometers and gas monitors to detect warning signs of eruptions or earthquakes.
• Prediction: While exact prediction remains challenging, scientists can forecast potential hazard zones by monitoring tectonic movements.
• Protection: Constructing earthquake-resistant buildings and implementing safety measures like automatic shut-off switches.
• Planning: Developing evacuation plans, reinforcing infrastructure, and educating the public on preparedness measures 

Immediate and Long-Term Responses

In the aftermath of a natural disaster, immediate responses focus on:

• Evacuating people, treating injuries, and securing basic necessities like food and shelter .

Long-term responses involve:

• Rebuilding homes and infrastructure, improving communication and forecasting systems, and boosting economic recovery through initiatives like tourism .

Key Takeaway

Understanding the dynamics of natural hazards, their potential impact, and available mitigation strategies is crucial for safeguarding human lives and property. Continuous efforts in monitoring, prediction, protection, and planning are essential to minimise the devastating effects of these events.

Glossary of Key Terms

• Natural Hazard: A natural process or event that poses a threat to human life or property.
• Geological Hazard: A hazard caused by land processes, such as earthquakes, volcanic eruptions, and landslides.
• Meteorological Hazard: A hazard caused by weather and climate, such as hurricanes, tornadoes, and floods.
• Vulnerability: The susceptibility of a population to the impacts of a hazard.
• Capacity to Cope: The ability of a population to withstand and recover from the impacts of a hazard.
• Primary Effects: The immediate impacts of a hazard event.
• Secondary Effects: The consequences of a hazard that occur later, often as a result of the primary effects.
• Tectonic Plates: Large, moving slabs of the Earth’s lithosphere that interact with each other.
• Plate Margin: The boundary between two tectonic plates.
• Destructive Plate Margin: A boundary where two plates move towards each other.
• Constructive Plate Margin: A boundary where two plates move apart.
• Conservative Plate Margin: A boundary where two plates slide past each other.
• Volcano: A rupture in the Earth’s crust that allows molten rock, ash, and gases to escape.
• Earthquake: A sudden shaking of the ground caused by the release of energy in the Earth’s crust.
• Focus: The point beneath the Earth’s surface where an earthquake originates.
• Epicentre: The point on the Earth’s surface directly above the focus of an earthquake.
• Magnitude: A measure of the energy released by an earthquake.
• Monitoring: Regularly observing and recording data about a potential hazard to detect changes and predict events.
• Prediction: Using scientific data and models to forecast the occurrence of a hazard event.
• Protection: Measures taken to safeguard people and property from the impacts of a hazard.

Quiz

Instructions: Answer the following questions in 2-3 sentences each.

1. What are the two main types of natural hazards? Provide an example for each type.
2. Explain the difference between primary and secondary effects of natural hazards. Give an example of each.
3. Describe the three types of plate margins. What geological activities are associated with each?
4. How are volcanoes formed at destructive plate margins?
5. Why do earthquakes occur at all three types of plate margins?
6. What is the difference between the focus and epicentre of an earthquake?
7. Explain two reasons why people choose to live in areas at risk from tectonic hazards.
8. Describe two methods used for monitoring volcanic eruptions.
9. Outline three ways buildings can be protected from earthquake damage.
10. What are two steps governments can take to plan for earthquakes and volcanic eruptions?

Quiz Answer Key

1. The two main types of natural hazards are geological hazards, caused by land processes like earthquakes (e.g., the 2015 Nepal earthquake), and meteorological hazards, caused by weather and climate, like hurricanes (e.g., Hurricane Katrina).
2. Primary effects are the immediate impacts caused by the hazard itself, such as buildings collapsing due to an earthquake. Secondary effects happen later on, often as a result of the primary effects, like the spread of disease due to contaminated water supplies after an earthquake.
3. The three types of plate margins are: destructive (where plates move towards each other, leading to volcanoes and earthquakes), constructive (where plates move apart, forming volcanoes and earthquakes), and conservative (where plates slide past each other, causing earthquakes).
4. At destructive plate margins, the denser oceanic plate subducts beneath the continental plate. The oceanic plate melts, forming magma, which rises through cracks in the crust and erupts to form volcanoes.
5. Earthquakes occur at all three types of plate margins because of the movement and interaction of tectonic plates. These movements create stress and pressure, which are eventually released as seismic waves, causing earthquakes.
6. The focus of an earthquake is the point beneath the Earth’s surface where the earthquake originates. The epicentre is the point on the Earth’s surface directly above the focus.
7. People choose to live in areas at risk from tectonic hazards because of: economic reasons, such as fertile volcanic soil attracting farmers or tourism related to volcanic activity, and lack of alternatives, as some people cannot afford to move or are unaware of the risks.
8. Two methods for monitoring volcanic eruptions are: using seismometers to detect small tremors and vibrations that precede eruptions, and analysing gases and changes in the shape of a volcano, which can indicate rising magma.
9. Buildings can be protected from earthquake damage by: using reinforced concrete, which can absorb earthquake energy, installing automatic shut-off switches for gas and electricity to prevent fires, and securing objects to prevent them from falling and causing injury.
10. Governments can plan for earthquakes and volcanic eruptions by: developing evacuation plans to guide people to safety and creating hazard maps to identify high-risk areas and guide development away from those zones.