Section A: The Challenge Of Natural Hazards
Overview
On 27 February 2010 an earthquake of magnitude 8.8 struck off the coast of Chile. On 25 April 2015 an earthquake of magnitude 7.8 struck Nepal. The Chilean earthquake released far more energy, yet it killed about 525 people; the Nepalese one killed close to 9,000. Nothing about the rocks explains that difference. Everything about the two countries does. That gap between the size of an event and the size of the disaster is the single most important idea in this whole section.
In this lesson you will build the physical machinery first: why plates move, what happens at each kind of margin, why the world's tropical storms sit in the same narrow bands year after year, and why the atmosphere circulates in cells at all. Then you will use that machinery to answer the questions the examiner actually asks. Why do people stay in places they know will shake? Which responses matter most, the ones in the first week or the ones in the following decade? And how much of the changing climate is us?
Objectives
- Natural hazards pose major risks to people and property.
- Earthquakes and volcanic eruptions are the result of physical processes.
- The effects of, and responses to, earthquakes and volcanoes vary between areas of contrasting levels of wealth.
- Management can reduce the effects of a tectonic hazard.
- Weather hazards Global atmospheric circulation helps to determine patterns of weather and climate. Tropical storms (hurricanes, cyclones, typhoons) develop as a result of particular physical conditions.
- Tropical storms have significant effects on people and the environment.
- Climate change Climate change is the result of natural and human factors, and has a range of effects.
- Managing climate change involves both mitigation (reducing causes) and adaptation (responding to change).
- Definition of a natural hazard; types of natural hazard; factors affecting hazard risk.
- Plate tectonics theory.
- Global distribution of earthquakes and volcanic eruptions and their relationship to plate margins. Physical processes taking place at different types of plate margin (constructive, destructive and conservative) that lead to earthquakes and volcanic activity. Primary and secondary effects of earthquakes and volcanoes.
- Immediate and long-term responses to hazards resulting from earthquakes and volcanoes. Use named examples to show how the effects and responses to tectonic hazards vary between two areas of contrasting levels of wealth. Reasons why people continue to live in areas at risk from earthquakes and volcanoes. How monitoring, prediction, protection and planning can reduce the risks from earthquakes and volcanoes.
- General atmospheric circulation model: pressure belts and surface winds.
- Global distribution of tropical storms (hurricanes, cyclones, typhoons).
- An understanding of the relationship between tropical storms and general atmospheric circulation. Causes of tropical storms and the sequence of their formation and development. The structure and features of a tropical storm; how climate change might affect the distribution, frequency and intensity of tropical storms. Primary and secondary effects of tropical storms.
- Immediate and long-term responses to tropical storms. Use a named example of a tropical storm to show its effects and responses. How monitoring, prediction, protection and planning can reduce the effects of tropical storms.
- Evidence for climate change from the beginning of the Quaternary period to the present day.
- Possible causes of climate change:
- natural factors - orbital changes, volcanic activity and solar output
- human factors - use of fossil fuels, agriculture and deforestation. Overview of the effects of climate change on people and the environment. Managing climate change:
- mitigation - alternative energy production, carbon capture, planting trees, international agreements
- adaptation - change in agricultural systems, managing water supply, reducing risk from rising sea levels.
Mind map
This topic is mapped out so you can see how the ideas connect.
Open the mind map in the app
Lesson Note
Complete Note Available on the Green Bridge App
Get the Green Bridge CBT app on your phone or computer for the complete IGCSE library: past papers, mark schemes, mind maps, flashcards and audio lessons.
Lesson Evaluation
Congratulations on completing the lesson on Section A: The Challenge Of Natural Hazards. Now that youve explored the key concepts and ideas, its time to put your knowledge to the test. This section offers a variety of practice questions designed to reinforce your understanding and help you gauge your grasp of the material.
You will encounter a mix of question types, including multiple-choice questions, short answer questions, and essay questions. Each question is thoughtfully crafted to assess different aspects of your knowledge and critical thinking skills.
Use this evaluation section as an opportunity to reinforce your understanding of the topic and to identify any areas where you may need additional study. Don't be discouraged by any challenges you encounter; instead, view them as opportunities for growth and improvement.
- At which type of plate margin is crust neither created nor destroyed? A. Constructive B. Destructive C. Conservative D. Collision Answer: C
- Which of the following is a secondary effect of an earthquake? A. A bridge collapses as the ground shakes B. A fire spreads after a gas main fractures C. A road surface cracks open D. A wall falls on a parked car Answer: B
- What is the minimum sea surface temperature normally needed for a tropical storm to form? A. About 17 degrees Celsius B. About 22 degrees Celsius C. About 27 degrees Celsius D. About 32 degrees Celsius Answer: C
- Which of these is an example of mitigation rather than adaptation? A. Building a sea wall B. Breeding a drought tolerant crop C. Installing carbon capture at a power station D. Raising houses on stilts Answer: C
- Where in a tropical storm are the strongest winds found? A. In the eye B. In the eyewall C. In the outermost rainband D. Evenly throughout the storm Answer: B
Work through these questions in the app
Work through these questions in the app
Recommended Books
Practice Mock Questions
Want to practice mock questions on Section A: The Challenge Of Natural Hazards? Download the Green Bridge CBT app to access mock questions and full practice assessments for this topic.
Download The App On Google Playstore
Everything you need to excel in your exams
