As the asthenosphere is a highly viscous layer of the earth and is a mechanically weaker and ductile region and is upper part of the earth and its depth range for 50 to 200 meters that is below the mid-oceanic ridges and its thickness depends on the temperature.
In some regions, the depth can be of 700 km, as the temperature increases at greater depths the rocks get deformed and thus rigid lithosphere begins to float on this layer and causes the movement of a tectonic plate.
