ThinkRankOur Changing Earth
Earth’s surface changes through internal forces such as earthquakes and volcanoes and external processes such as weathering, erosion, and deposition. These processes create landforms and hazards. Risk is shaped not only by nature but also by where and how people build and prepare.
Learning Objectives
- •Distinguish internal and external processes
- •Explain weathering, erosion, and deposition
- •Describe common earthquake and volcanic effects
- •Suggest ways to reduce disaster risk
Key Concepts
Landforms are dynamic
Rivers, glaciers, waves, wind, and gravity continuously wear down and build up land.
Hazard is not the same as disaster
A natural event becomes more damaging when people, buildings, and systems are exposed and vulnerable.
Preparedness reduces risk
Building codes, early warning, land-use planning, drills, and community knowledge save lives.
Terminology
Historical Insight
River valleys
Erosion cuts channels while deposition creates floodplains, deltas, and other features.
Coastal change
Waves erode cliffs and move sediment, affecting beaches, ports, and settlements.
Quick Check
What is deposition?
How can a community reduce earthquake risk?
How do rivers shape landforms?
How to use this lesson
Read the overview first, then explain the main idea in your own words before checking the key concepts. Use the quick-check questions without looking at the answer. For examination preparation, verify dates, definitions, and syllabus requirements against your official textbook and school or examination-board guidance.