The San-Andreas fault line.
EARTHQUAKE
earthquake
The plates rub together causing the rocks to move and it causes the ground to shake forming an earthquake. The more the plates move, the bigger the earthquake number.
An earthquake is started when two plates (which lie under the Earths surface) rub together this creates movement which then sometimes pulls/pushes at the earths surface and creates giant cracks in the earths surface... and that is how an earthquake is started.
an earthquake...?
The Italian earth quake was most probably caused by the movement of the Eurasian and African tectonic plates. Convection currents in the earths mantle cause these plates to move which in turn causes stresses at the plate boundaries. When these stresses are released the movement is very sudden. This is the movement said to be an earthquake.
it happened because of the earths movement no offence but that wasnt a very good answer. it happened because the asthenosphere (not spelt correctly) in the mantle moved because the plates flowed over the top of the liquid magma. No! it was the earths plates sliding against eachother that cause the earthquake.
the movement of earths plates or crust
because it shifs the earths plates
the tectonic plates are shifting under the earths surface.
When the two different kinds of plates collide, a part of the world starts to shake exactly like an earthquake.
A mega earthquake is seismic activity below the earths crust that causes fluctuations in the earths tectonic plates. This forces the ground to shake and the earths crust to crack.