2.3 - Earthquakes - notes

The occurrence of earthquakes at plate margins

:::summary[Earthquakes at plate margins]{intro="How the movement of tectonic plates at destructive and conservative margins causes earthquakes."}

Earthquakes are natural phenomena that happen primarily at specific boundaries between tectonic plates, known as plate margins. These events are caused by the movement and interaction of these massive sections of the Earth's crust.

Causes of earthquakes at plate boundaries

• Destructive margins - At these boundaries, two plates move towards each other, and one is forced beneath the other into the mantle. If the descending plate becomes stuck, it builds up immense pressure in the surrounding rock layers.
• Conservative margins - Here, two plates slide past each other horizontally. When they get stuck due to friction, tension accumulates in the rocks.
• Release of tension - When the built-up stress in the rocks is finally released, it generates powerful vibrations known as seismic waves, resulting in an earthquake.

Key features of earthquakes

Measuring earthquakes with the Richter Scale

Effects of earthquakes by Richter magnitude

:::summary[Effects by magnitude]{intro="The typical impacts of earthquakes at different points on the Richter Scale."}

The impact of an earthquake largely depends on its magnitude as measured by the Richter Scale. Higher magnitudes correlate with more severe destruction and noticeable ground movement.

Impact of earthquakes by magnitude