Explain how the actions around a fault can result in an earthquake?

Answer 1

Earthquakes are tremors or vibrations in the Earth's crust that are caused by the build up or accumulation of pressure (more correctly termed stress). This can commonly occur where the rock masses on two sides of a fault become locked in position.

This accumulation of stress causes the rocks that make up the crust on either side of the fault zone to deform elastically. This is very similar to what happens when you squash or stretch a spring and causes a form of energy to be stored in the rocks of the crust - technically described as elastic potential energy.

When this stress gets to large, it exceeds the strength of the rocks in the crust and causes a brittle failure. Brittle failures are failures where fractures form through the material.

This sudden brittle failure allows the fault zone to move again and causes all of the elastic potential energy to be released at one time in the form of seismic waves, just as if a spring or elastic band that was being stretched suddenly snapped.

These seismic waves cause the tremors that people feel on the surface and which can cause damage to buildings and other structures.