Every card in Rivers and coasts, Year 8: more practice
The whole deck, in order — so you can read it through before your child ever sees it.
- What is it called when seawater is forced into cracks in a cliff, compressing the air and widening the cracks?
Hydraulic action
HintThe sheer force of the water itself does the work.
WhyEach wave pushes air in the crack under pressure, and as the water drains back the air expands. Repeated again and again, this breaks rock apart.
- Why does a headland of hard rock stick out into the sea while a bay of soft rock lies beside it?
The soft rock erodes faster, leaving the hard rock behind
HintCompare how quickly different rocks wear away.
WhyWaves cut back soft rock such as clay more quickly than hard rock such as chalk or granite. This is called differential erosion.
- A waterfall forms where a river flows over hard rock lying on top of soft rock. Which rock is worn away faster?
The soft rock
HintThe one that is easier to erode.
WhyThe soft rock below is undercut, leaving the hard rock as an overhang. Eventually the overhang collapses and the waterfall steps back upstream.
- A waterfall keeps retreating upstream over thousands of years. What steep-sided valley does it leave behind?
A gorge
HintThink of a narrow, deep valley with rocky walls.
WhyEach time the overhang collapses the waterfall moves back, and the channel it abandons becomes a gorge.
- On the inside of a meander, the water is slow. What does the river do there?
It deposits sediment, building a slip-off slope
HintSlow water cannot carry as much load.
WhyThe sediment piles up into a gently sloping bank of sand and gravel, while the fast outside bend erodes a steep river cliff.
- A meander loop is cut off from the river when the narrow neck between two bends is eroded through. What is the cut-off loop called?
An oxbow lake
HintIt is named after a curved part of an old farm yoke.
WhyDeposition seals the ends of the abandoned loop, leaving a curved lake. Over time it can dry out into marshy ground.
- Waves attack a crack in a headland. After the crack widens into a cave, what landform forms if the cave is cut right through?
An arch
HintThink of a rock doorway into the sea.
WhyWaves keep eroding the back of the cave until it breaks through the other side of the headland, leaving an arch.
- When the sea wears down a stack, what small rocky remnant is left, often only visible at low tide?
A stump
HintThink of what is left when a tree is cut down.
WhyThe sequence is crack, cave, arch, stack, stump. Waves keep eroding the stack until only a low remnant remains.
- Which type of rock lets very little water soak in, so rainwater runs off into the river and makes a flood more likely?
Impermeable rock
HintThink about the land the rain falls on.
WhyOn impermeable rock, water cannot sink in, so it runs over the surface to the river and the river fills faster.
- Cutting down forests on a hillside raises flood risk downstream. Why?
Fewer trees intercept rain and take up water, so more runs quickly to the river
HintThink about what leaves and roots do with rainwater.
WhyTrees catch rain on their leaves and draw water up through their roots. Without them, water reaches the river faster and the peak flow is higher.
1★ KS3-GEOG-RIV-0036
2★ KS3-GEOG-RIV-0037
3★ KS3-GEOG-RIV-0038
4★ KS3-GEOG-RIV-0039
5★ KS3-GEOG-RIV-0040
6★ KS3-GEOG-RIV-0041
7★ KS3-GEOG-RIV-0042
8★ KS3-GEOG-RIV-0043
9★ KS3-GEOG-RIV-0044
10★ KS3-GEOG-RIV-0045
Keep what you learn
Here, nothing is saved. In your child’s own sky every card is scheduled — it comes back just before they’d forget it — and the professor who wrote it is one tap away.