---
title: "Coasts on the Move"
description: "Waves take material from one part of a coast and put it down further along, so beaches, spits and bars are all sediment in transit. A coastline is a balance sheet that never quite settles."
canonical: https://lightmysky.com/learn/geography/coasts-on-the-move-mt_IVnXDRpfqE
source: https://lightmysky.com/learn/geography/coasts-on-the-move-mt_IVnXDRpfqE.md
retrieved: 2026-09-12
---

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# Coasts on the Move

Waves take material from one part of a coast and put it down further along, so beaches, spits and bars are all sediment in transit. A coastline is a balance sheet that never quite settles.

Subject: Geography · Area: Physical Geography · Ages 11 to 13
Page: https://lightmysky.com/learn/geography/coasts-on-the-move-mt_IVnXDRpfqE

## Ready when they can

- Explain how waves arriving at an angle move sediment along a beach
- Say how a headland and a bay form on a coast made of alternating hard and soft rock
- Name one coastal landform made by erosion and one made by deposition

## Lesson: Coasts That Never Sit Still

Waves that hit at an angle push sand sideways along the shore. That zigzag trip has a name: longshore drift.

Soft rock wears back fast into curved bays, while tough rock juts out as headlands. Erosion builds cliffs, caves, arches and stacks, while dropping builds beaches, spits and bars.

**Example.** Sand piles at one end of a beach because drift feeds it there. Block the drift with a wall and the beach further along starves.

**Tip.** People defend shores with hard walls that block wave force, or soft plant buffers that trap sand and drink up wave force.

**Recap.** Waves move sand along, carve the soft rock first, and drop new land where they slow.

## Practice

8 questions on this page, each with its working shown.

## Needs first

- [Erosion and weathering](https://lightmysky.com/learn/science/erosion-and-weathering-mt_vAP_A986IQ)
- [From Source to Sea](https://lightmysky.com/learn/geography/from-source-to-sea-mt_VuUB9PiYan)

## Opens up

- [Choosing How to Defend a Coast](https://lightmysky.com/learn/geography/choosing-how-to-defend-a-coast-mt_3Px4N4va3o)
- [What the Ice Left Behind](https://lightmysky.com/learn/geography/what-the-ice-left-behind-mt_D-aB1k0K73)
- [Reading a Landscape Off a Map](https://lightmysky.com/learn/geography/reading-a-landscape-off-a-map-mt_MWlY_e59Rg)