An earthquake is caused by the layers of earth colliding. It causes “stress” on the earth and therefore creates an earthquake! This is also known as the geosphere!
If I am correct (it has been a while since I've learned about this) an earthquake is caused by two tectonic plates rubbing against each other which causes the land to shake violently until they stop moving. The pressure of magma under the plates causes them to shift and collide. The evidence it provides is magma from mantle builds pressure causing the tectonic plates that are part of the crust (the part we live on) to shift.
I hope I explained this well. I'm sorry if it's wrong, it's been about 4 years since I learned about this. However I'm sure this is correct.
First off, let's look into how an earthquake happens:
As the plate move apart or collide given the convection current of magma, stress is built up with continuous plate movements. The pressure is then greater than the elastic strength of the rock. Rock breaks, the pressure of energy is released in the form of seismic waves. Ground vibrates, resulting in earthquake.
How it provide evidence about the layers of Earth, is that the lower the layer, the hotter it is, which then cause the convection current of magma to happen,hence affecting the lithosphere.
