4.1.1 The characteristics of the layers of the Earth & the names of the tectonic plates.

structure of the earth & plate names - igcse worksheet

Objective: To discover how our planet it structured and how tectonic plates move and their resultant features. 


You will be completing the work booklet above (orange tab).  Each of the tasks corresponds with a task below. 
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Task 1 - It is a good skill to be able to complete sketch maps in IGCSE Geography.

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Click here to play a game! 


Task 2 - Label each of the plates on the map in your booklet and add the direction arrows and identify and label 'The Pacific Ring of Fire'. 


Task 3 - There are two types of 'earth's crust':
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i. Oceanic Crust
ii. Continental Crust

Using this link, explain the main differences between them both.  You may want to use Chat GPT to simplify the 'formation' part by instructing it carefully that you are an IGCSE Geography student and need a more basic definition. 


On the Move - Continental Drift 

Task 4 - Watch the video to the right hand side and then have a play with this fantastic tool. Stop the video when you recognise any landmass e.g. North America. What period was that? 


Task 5 - Take a screenshot of now and 100 million years from now on the YouTube video. Annotate the major differences between now and in the future. Try to find at least five differences. How has the location of your home country changed? 

The layers of the Earth - mix and match activity 


"This is the thickest section of the earth with a diameter of about 2900km. It is often described as being semi-molten, but in reality the top is hard rock and as you near the outer core it is beginning to melt (magma). Convection currents are found in this layer".


"This layer is believed to be liquid and largely made of iron and nickel. It is extremely hot with temperatures up to 5,500 degrees centigrade".

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"It is solid and is the layer we live on. It is usually between 10km and 60km thick. Its thickness is often referred to as the relative thickness of an apple skin (when compared to the size of an apple)".


"This layer is believed to be solid, because of the immense pressure placed upon it. It contains the centre of the earth which is about 6,378km from the surface. It is also extremely hot at about 5,500 degrees centigrade."
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4.1.2 How tectonic plates move...

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The theory of plate tectonics states that the Earth’s outer layer is divided into large plates that move slowly over the semi-molten mantle, causing earthquakes, volcanoes, and mountain building. In science, a theory is a well-tested explanation supported by evidence, and is not just a guess. Although there is strong evidence for plate movement, we cannot directly observe what happens deep inside the Earth, so it is impossible to prove it with complete certainty.
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​Theory 1 - Convection Currents - For many years, scientists believed that convection currents in the Earth’s mantle were the main force moving the tectonic plates. According to this theory, heat from the Earth’s core causes molten rock in the mantle to rise, spread out beneath the crust, cool, and then sink back down, creating circular currents. These slow-moving convection cells were thought to drag the plates sitting above them, causing them to move.

​Theory 2 - Ridge Push, Slab Pull - However, more recent research suggests that convection currents alone cannot fully explain how plates move. Instead, two other forces are now considered more important: ridge push and slab pull.

Ridge push happens at mid-ocean ridges, where new crust forms as magma rises and solidifies. The newly formed rock is warm and less dense, so it pushes the older, cooler, denser rock away from the ridge, helping to move the plates apart.

Slab pull occurs at subduction zones, where a dense oceanic plate is pulled down into the mantle beneath a lighter continental or oceanic plate. As the sinking plate moves downward, it pulls the rest of the plate behind it, acting like a powerful conveyor belt.

Check out the diagram below that the rather wonderful Geography teacher Mr Hamill (in Northern Ireland) produced recently to illustrate this process. 

Task 6 - Complete the worksheet below to improve your understanding of both theories above.  For the final task (question 5), you will need to refer to the text below. 

task 6 worksheet - theories of plate tectonics

Scientists originally thought that tectonic plates were mainly moved by convection currents in the mantle, which were believed to drag the plates from below as hot material rose and cooler material sank. At the time, this idea was based on limited evidence because scientists had no direct way to observe the structure or temperature of the deep Earth. As technology developed, global seismic networks began recording thousands of earthquake waves, allowing the creation of seismic tomography models.

Seismic tomography compares the arrival times of seismic waves at stations around the world: waves travel faster through cold, dense rock and slower through hotter, less dense rock. By analysing these differences, scientists can map temperature variations inside the mantle and identify features such as cold, sinking slabs beneath subduction zones or hotter regions beneath mid-ocean ridges.

​Further evidence from GPS measurements now shows precise plate speeds and directions, revealing patterns that match the influence of slab pull and ridge push. Together, these modern techniques provide a much more detailed understanding of plate motion than was possible when the convection current theory was first proposed.

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4.1.3 Types of plate boundary & the location of earthquakes and volcanoes.

How the Plates Move

The Earth’s outer layer, called the lithosphere, is broken into large sections known as tectonic plates. These plates float on the semi-molten asthenosphere below and are moved by forces such as slab pull, ridge push, and mantle convection. Their movement is very slow, only a few centimetres per year, but it shapes the surface of our planet and causes many natural hazards, such as earthquakes and volcanoes.

There are four main types of plate movement studied at IGCSE level:

Divergent (constructive) boundaries – where plates move away from each other, forming new crust at mid-ocean ridges or rift valleys.

Convergent (destructive) boundaries – where plates move towards each other, causing subduction, earthquakes, and volcanic activity.

Conservative (transform) boundaries – where plates slide past each other, leading to friction and powerful earthquakes but no new or destroyed crust.

Collision boundaries – where two continental plates move together, crumpling and folding to form large mountain ranges, such as the Himalayas.

Watch the short video below that explains this. 

Part 1 - Volcanoes

Task 7 - Where are the large volcanoes globally? -

Find the locations of the following volcanoes:

a. Mount St Helens
b. Cotopaxi
c. Mont Pelée
d. Eyjafjallajokull
e. Mount Vesuvius
f.  Krakatoa
g. Mount Pinatubo
h. Unzen
i. Mount Etna
j. Nevado del Ruiz

​Plot and annotate the locations of these volcanoes onto the worksheet above.
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Task 8 - What plate boundaries are associated with volcanoes?

Now using the video above right and the GIF, complete a diagram on the second page of your Task 7 & 8 worksheet with accompanying notes on how destructive plate boundaries can result in the formation of volcanoes. 

Need help? You might want to use this basic diagram to help you, but you will need to add annotations. 

task 7 & 8 - volcano location & plate action

Part 2 - Earthquakes

Starter: Spend 5 minutes watching the National Geographic video to the right. 


Task 9 - Where do powerful earthquakes happen? 


Click here to access the Wikipedia information on earthquakes and in particular the most powerful quakes of all time.


Plot the top 10 earthquake (by magnitude) locations onto the same worksheet that you plotted the volcanoes on (from last lesson). Use a the symbol included in the key to show the approximate locations of earthquake events. 
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Task 10 - Finding out more about the causes of earthquakes


Please complete all tasks set out on the worksheet below. 


For the final spider diagram task, use the last video to the right to make a note of the key factors impacting the severity of an earthquake event. 
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Task 10 - earthquakes and tectonic plates

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