Which layer of the Earth is the thin, solid outer one?

the crust. The plates are pieces of crust.

What moves the tectonic plates?

convection currents in the mantle. Hot rock rises, spreads, cools and sinks.

What happens at a divergent plate boundary?

the plates move apart. Magma rises into the gap.

one plate being forced down beneath another. It happens at convergent boundaries.

Which boundary has earthquakes but no volcanoes?

conservative. The plates slide past each other and no magma forms.

A volcano erupts in the middle of a plate, far from any boundary. What explains it?

a hotspot. Hot rock rises through the mantle and breaks through the crust.

The Earth's structure and plate boundaries · Cambridge IGCSE Environmental Management

In plain words

The ground feels solid and still. It is neither. The Earth's surface is a cracked shell, and its pieces drift a few centimetres a year, about as fast as fingernails grow. Almost every earthquake and volcano sits on one of the cracks.

8 things to know

The Earth has three main layers. The crust is the thin, solid outer layer. The mantle is the thick layer below it, made of hot rock that flows very slowly. The core is at the centre and is the hottest part.
There are seven continents: Africa, Antarctica, Asia, Europe, North America, Oceania and South America.
The crust is broken into large pieces called tectonic plates. Earthquakes and volcanoes are not spread evenly over the Earth. Most occur in narrow belts along the plate boundaries.
Heat from the core makes rock in the mantle rise, spread out, cool and sink again. These convection currents move the plates that float on top.
At a divergent, or constructive, plate boundary the plates move apart. Magma rises to fill the gap. This causes volcanic activity and earthquakes.
At a convergent, or destructive, plate boundary the plates move together. One plate is forced down beneath the other, which is called subduction. This causes earthquakes and a line of volcanoes.
At a conservative plate boundary the plates slide past each other. This causes earthquakes. There are no volcanoes, because no magma is made.
A hotspot is a place where very hot rock rises through the mantle and breaks through the crust, away from a plate boundary. It explains volcanoes in the middle of a plate, such as those of Hawaii.

Worked example

A map shows a line of volcanoes running along the edge of a continent, with frequent earthquakes. Identify the type of plate boundary and explain the volcanoes.

A line of volcanoes with earthquakes points to a convergent, or destructive, boundary.
One plate is being subducted beneath the other.
The plate that sinks melts, and the magma rises through the crust above to form the line of volcanoes.

Tips and tricks

Earthquakes happen at all three types of boundary. Volcanoes form at divergent and convergent boundaries, and not at conservative ones.
Each boundary has two names. Divergent is the same as constructive, and convergent is the same as destructive. Know both, because either may be used.

6 questions, about 2 minutes.

It lands in your notebook with its questions as flashcards.

The Earth's structure and plate boundaries: 6 questions and answers

These are the quiz’s questions. Do the quiz first, then come back here for the ones that got you.

Which layer of the Earth is the thin, solid outer one?
- the crust (the answer)
- the core
- the mantle
- the stratosphere
The plates are pieces of crust.
What moves the tectonic plates?
- the wind
- ocean tides
- the pull of the Moon
- convection currents in the mantle (the answer)
Hot rock rises, spreads, cools and sinks.
What happens at a divergent plate boundary?
- the plates move apart (the answer)
- one plate sinks beneath another
- the plates slide past each other
- the plates stop moving
Magma rises into the gap.
What is subduction?
- two plates sliding past each other
- one plate being forced down beneath another (the answer)
- magma cooling at the surface
- two plates moving apart
It happens at convergent boundaries.
Which boundary has earthquakes but no volcanoes?
- divergent
- convergent
- conservative (the answer)
- constructive
The plates slide past each other and no magma forms.
A volcano erupts in the middle of a plate, far from any boundary. What explains it?Stretch
- a conservative boundary
- subduction
- an earthquake
- a hotspot (the answer)
Hot rock rises through the mantle and breaks through the crust.

6 questions

Tap an answer and you’ll see straight away whether it’s right, and why.

Worksheet

3 questions, 8 marks. Write your answers on paper, then check them.

The Earth's structure and plate boundaries

Cambridge IGCSE Environmental Management 0680 · 8 marks · papermunch.org

Name ______________________________ Date ______________

Name the three main layers of the Earth, starting from the outside.[3]
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Crust, mantle, core.
I got this one
Explain how convection currents cause tectonic plates to move.[3]
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Heat from the core warms rock in the mantle, which rises. It spreads out beneath the crust, cools and sinks. This movement drags the plates above it.
I got this one
Describe what happens at a conservative plate boundary.[2]
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Two plates slide past each other. This causes earthquakes, but there are no volcanoes.
I got this one

Answers: The Earth's structure and plate boundaries

1. Crust, mantle, core.
2. Heat from the core warms rock in the mantle, which rises. It spreads out beneath the crust, cools and sinks. This movement drags the plates above it.
3. Two plates slide past each other. This causes earthquakes, but there are no volcanoes.