The lithosphere is located in Earth's mantle. It is the first mantle layer out of three. It is made of two parts: the crust and the upper part of the mantle. The rocks in the lithosphere are cooler and stronger than rocks in the asthenosphere; it is a difference in temperature and pressure. The lithosphere can be about 15 to 300 km wide and is said to be divided into two parts called tectonic plates; seismic velocity in the lithosphere is very weak.