Waves and Tides — Revision notes

Waves

The movement of energy across water driven by wind blowing across the surface of the sea or ocean

Tides

The regular, predictable rise and fall of the sea about every 12 hours, caused mainly by the gravitational pull of the Moon

Fetch

The distance a wave has travelled across open water before reaching the shore, which directly influences wave size

Swash

The movement of water rushing up a beach toward the land when a wave breaks

Backwash

The movement of water pulling back down a beach toward the sea under the force of gravity

Constructive waves

Waves with a strong swash and a weak backwash that deposit material and build beaches up over time

Destructive waves

Waves with a weak swash and a very strong backwash that drag material away and cause coastal erosion

What this lesson covers

How well do you know each one? Be honest: red means go back over it.

• Explain what causes waves and what causes tides, and why they are differentNot yetSort ofGot it
• Define fetch and explain how it affects the size and power of a waveNot yetSort ofGot it
• Describe swash and backwash and explain the part each playsNot yetSort ofGot it
• Explain the difference between constructive and destructive wavesNot yetSort ofGot it
• Describe how destructive waves change a coastline over timeNot yetSort ofGot it
• Use coastal vocabulary correctly when describing a beachNot yetSort ofGot it

Test yourself

Cover the answer, say it out loud, then check the full quiz on the lesson page.

• What causes tides?
• Which wind creates the largest waves?
• A beach is slowly getting wider — which wave type is responsible?

Topic quiz

11 questions on this topic only — not mixed with anything else, one at a time.

Spelling challenge

Read the definition, then type the correct spelling of the term. Uses the same terms as above.