Personal Response 5 : Earthquakes part 1

Why do Earthquakes happen?

Although the ground we walk on seems solid, the earth is actually made up of huge pieces of flat rock called tectonic plates.
These move very slowly, and where they meet is called a fault.
When the plates rub together, the movement forces waves of energy to come to the earth's surface. This causes tremors and shakes - and this is what causes earthquakes.

Are they dangerous?

Earthquakes can be very dangerous, if you are in the wrong place. They can make buildings fall down and set off landslides, as well as having many other deadly effects.
An earthquake which occurs on the seafloor can push water upwards and create massive waves called tsunamis.
These waves can reach speeds of up to 500 kilometres per hour and cause massive devastation to anything in their path.
Earthquakes are measured on the Richter Scale.
The higher the number on the scale, the more powerful the quake. The more powerful a quake is, the more damage it can cause.
Earthquakes have killed hundreds of thousands of people even though scientists are able to make buildings much safer than in the past.
Unfortunately many quakes happen in parts of the world where people can't afford to spend lots of money on safety measures.