Earthquakes KS2

What is an earthquake?

An earthquake is a shaking of the earth's surface. Earthquakes can be mild and barely felt, or intense and destructive.

What causes earthquakes?

The Earth is made up of several different layers. The crust is the outermost layer of the Earth. It is made up of plates of rock that fit together like a jigsaw. These are called tectonic plates.

The tectonic plates are constantly moving. They move a few centimetres every year. This might not sound like much, but when they meet, they sometimes get jammed together. The forces pushing the rock together then build up until the rocks distort. They judder past each other then fall back to their original shapes. This releases stored energy in seismic waves. It is these waves that cause earthquakes.  

Where do earthquakes occur?

Earthquakes can be felt anywhere in the world, but most earthquakes happen along faults where tectonic plates meet.

World map showing where earthquakes are most likely to occur

Which country has the most earthquakes?

Japan experiences the most earthquakes. This is because the country is sat upon four tectonic plates that are constantly moving against one another. Approximately 1,500 earthquakes occur there every year, but the majority are very mild and barely felt.  

How do we measure earthquakes?

Seismographs are instruments used to detect and record the seismic waves during an earthquake. The strength, or magnitude, of an earthquake is measured by a system called the Richter scale.

Across the world, there are several million earthquakes every year. However, only around 500,000 of these are detected, 100,000 can be felt and 100 cause damage. 

The effects of different magnitudes of earthquakes according to the Richter scale.