Contents
Key Stage 2
Meaning
An earthquake is when the ground shakes.
Key Stage 3
Meaning
An earthquake is when the ground shakes.
About Earthquakes
- Earthquakes are usually caused by tectonic plates rubbing against each other.
Key Stage 4
Meaning
An Earthquake is when the ground undergoes a violent shaking motion. This often results in damage to the local environment and severe loss of life.
About Earthquakes
Earthquakes occur along all three types of Tectonic Plate Margin when tension builds up as the plates move.
At Destructive Plate Margins as the two plates move down past each other into the mantle friction causes tension to build up and therefore the plates get stuck. As the plates are released and jerk away from each other they release shock waves that that spread from the focus deep in the mantle where the plates are coming together. The shock waves are then felt on the surface of the crust and they are most strongly felt at the Epicentre which is the point directly above the focus. This is an earthquake.
At Conservative Plate Margins as the plates grind past each other friction causes tension to build between the plates as they move and this means that they eventually become stuck. As the plates are released and jerk away from each other they release shock waves that that spread from the focus deep in the mantle. The shock waves are then felt on the surface of the crust in the form of an earthquake. The shock waves are most strongly felt at the Epicentre which is the point directly above the focus.
At Constructive Plate Margins the plates are moving away from each other and this causes cracks in the plates as they move. Tension then builds in these cracks and is eventually released in the form of shock waves that can be felt of the surface of the earth at the crust as an earthquake.
Earthquakes come in a variety of strengths therefore there is a scale that shows you how strong each earthquake is and how much damage it is likely to do. This is called the moment magnitude scale. This scale measures the amount of energy released by an earthquake and is measured logarithmically. This means that a magnitude 2 earthquake is ten times stronger than a magnitude 1 earthquake. Earthquakes below magnitude 6 only cause slight damage to buildings and earthquakes magnitude 7 and above can cause high levels of damage and large loss of life.