The answer is Earth's Mantle
Lithosphere is a part of the earth's layer which includes the Crust and the uppermost mantle.
Lithosphere is further divided into Tectonic Plates and the movement of these tectonic plates is what causes earthquakes.
The movement of Lithosphere leads to the movement of the continents as we see them and is directly influence by the Earth's mantle which is about 2,900 km thick and makes up 84% of Earth's volume.
