In Earthquakes. it affects the earths crust because that's where earthquakes occur or start The earth is a hot liquid in the middle and the gases have to ex scape to the outside.So to do tha … t it pushes through rock and dirt making mountains and cracks are made along stress lines making the earth shake.6 people found this useful.t affects the earths crust because that's where earthquakes occur or start The earth is a hot liquid in the middle and the gases have to ex scape to the outside.So to do tha … t it pushes through rock and dirt making mountains and cracks are made along stress lines making the earth shake. 6 people found this useful.