Earthquakes and tsunamis

• Earthquakes are caused by the release of built-up pressure at plate boundaries.
• Earthquakes are the sudden violent shaking of the ground, which happens because the Earth's plates are constantly moving.
• Sometimes, because of friction, plates try to move but become stuck.
• Pressure builds up because the plates are still trying to move.
• When the pressure is released, it sends out huge amounts of energy causing the Earth's surface to shake violently.
• The point inside the Earth's crust where the earthquake originates from is known as the focus.
• The earthquake's energy is released in seismic waves, which spread out from the focus.
• The seismic waves are most powerful at the epicentre, which is the point on the Earth's surface directly above the focus of an earthquake.
• Earthquakes are found at all three plate boundaries: divergent, convergent and conservative plate boundaries.