GCSE · Geography · AQA · Spec 8035

Coastal deposition

Huge storm waves or a quiet little bay: which one ends up with the sediment? Most people guess wrong.

Follow the waves

Where does the sea drop its sediment?

The coast is shaped by a number of physical processes, and deposition is one of them. Walk this imaginary coast from the open sea into a sheltered bay. Tap each zone and see what the waves are doing with their sediment.

Zone 1 of 3

Open coast

Strong, powerful waves pound this stretch. They are still carrying their sediment, and nothing gets dropped. Deposition does not happen with waves like these.

Strong, powerful waves
Sediment still carried
No deposition

Strong waves on the open coast, low-energy waves in the bay, and the sediment is dropped in the bay. It's the quiet water, not the wild water, where deposition happens.

Watch out: This is a schematic, not a map. The line shows how much energy the waves have, not the shape of the land, and the zones are not to scale.

The because-chain

Reason it through

Why is sediment deposited in bays and sheltered areas?

Link 1 of 3

First link · your turn

Waves carrying sediment arrive in a bay or a sheltered area. What happens to their energy?

Locked — reveal the link above first

What do you think?

Big waves, big deposits?

Picture two places on the same coast. In one, huge, powerful waves are smashing in. In the other, a sheltered bay, small low-energy waves are rolling in.

Be honest: where do you think the sea drops its sediment?

Where the waves are strongest. Big waves bring the most with them, so they must drop the most.Anywhere the sea meets the land. Every wave leaves a bit of sediment behind.Where the waves lose energy, like in the sheltered bay.

How sure are you?

I'm sureI think soI'm guessing

Where the waves are strongest. Big waves bring the most with them, so they must drop the most.

This is a common misconception

It feels right, but it's backwards. Strong, powerful waves keep their sediment. Deposition does not happen with strong, powerful waves; it happens where waves are low-energy.

Anywhere the sea meets the land. Every wave leaves a bit of sediment behind.

This is a common misconception

Not every stretch of coast. Deposition happens in particular places: areas with low-energy waves, such as bays or sheltered areas. Where strong, powerful waves break, it doesn't happen.

Where the waves lose energy, like in the sheltered bay.

This matches the evidence

Spot on. Bays and sheltered areas have low-energy waves, and that's where deposition happens. The quiet bay wins, not the stormy stretch.

Strong, powerful waves hold on to their sediment. Low-energy waves, in bays and sheltered areas, drop it.

Your turn

Write the explanation yourself

Explain why sediment is deposited in coastal areas. [4 marks]

Your answer

0 words · your answer stays on this page and is not sent anywhere.

The mark scheme

Deposition happens where the waves are low-energy. (1 mark)
It happens in areas such as bays or sheltered areas. (1 mark)
The waves lose energy. (1 mark)
So they can no longer carry their load of sediment, and it is deposited (dropped). (1 mark)

Model answer

Sediment is deposited in areas where the waves are low-energy, such as bays or sheltered areas. When waves reach these areas they lose energy. This means they can no longer carry their load of sediment, so the sediment is dropped.

Say where, then say why, and join your reasons with 'so'.

UK note

AQA GCSE Geography: this is 3.1.3.2 Coastal landscapes in the UK, assessed in Paper 1 (Living with the physical environment).

WHAT YOU'VE LEARNED

A quick recap of today's lesson.

Where the sea drops its sediment, and why it happens there.

What you need to know

Deposition is one of a number of physical processes that shape the coast.
Coastal deposition happens in areas with low-energy waves, not with strong, powerful waves.
Bays and sheltered areas are the kinds of places where deposition happens.
Sediment is deposited where waves lose energy and can no longer carry their load.

The big picture

The coast is shaped by a number of physical processes, and deposition is one of them. Deposition is when waves drop the sediment they have been carrying. It happens in areas with low-energy waves, such as bays or sheltered areas, and it does not happen with strong, powerful waves. The reason is that the waves there lose energy and can no longer carry their load of sediment, so it is deposited.

Key points

1Deposition means waves dropping the sediment they were carrying.

2Low-energy waves drop sediment; strong, powerful waves don't.

3Look for bays and sheltered areas.

4Lose energy → can't carry the load → sediment deposited.

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Worked example

Problem

A made-up stretch of coast has three spots. Spot 1 is open coast where strong, powerful waves break. Spot 2 is a sheltered area where the waves are low-energy. Spot 3 is inside a bay, where the waves are also low-energy. At which spots would you expect deposition, and why?

⚠ Watch out

Saying deposition happens where the waves are biggest and most powerful. It's the other way round: strong, powerful waves keep their sediment, and deposition happens where waves are low-energy.

🧠

Memory hook

Think of carrying heavy shopping home. While you've got the energy, the bags come with you. Run out of energy and you put them down. Waves do the same with sediment: lose the energy, drop the load.

✓

Check yourself

Cover the page and answer in two short sentences: where on a coast does deposition happen, and why does it happen there?

Flashcards

(6)

What is coastal deposition?

Waves dropping (depositing) the sediment they have been carrying.

Is deposition the only process that shapes the coast?

No. The coast is shaped by a number of physical processes, and deposition is one of them.

Big stormy waves or gentle low-energy waves: which ones drop their sediment?

The gentle, low-energy ones. Deposition doesn't happen with big, powerful waves.

Name two kinds of place where coastal deposition happens.

Bays and sheltered areas.

In 'the waves can no longer carry their load', what is the load?

The sediment the waves are carrying.

What has to happen to waves before they drop their load?

They lose energy, so they can no longer carry it.

Tap any card to flip it, or use Study as deck to go through them one at a time. In the full lesson these run as a spaced-repetition deck — you rate each card Hard, Good or Easy and the tricky ones keep coming back until they stick.

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Where does the sea drop its sediment?

Big waves, big deposits?

Write the explanation yourself

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