The Difference Between a Lithosphere & Asthenosphere

Depth

• One of the things that characterizes the difference between the lithosphere and the asthenosphere is the depths to which these layers reach within the Earth itself. The lithosphere begins at the surface of the planet. Although the distance is hard to pinpoint exactly and is slightly variable, the lithosphere comprises approximately the first 50 miles of the Earth, starting from the surface and going toward the core. The asthenosphere begins where the lithosphere ends, and it extends to as much as 155 miles beneath the surface.

Movement

• The lithosphere includes two different parts of the Earth's crust. The lithosphere includes the very top of the mantle and the crust itself. This means the movement of the lithosphere is the movement of the massive tectonic plates that form the crust of the earth. Lithosphere movement creates earthquakes at times. (See References 3) The movement in the liquid of the asthenosphere actually drives the movement in the lithosphere.

Solidity

• The upper layer of the lithosphere is solid, although it is broken into the chunks known as the tectonic plates. The lithosphere also includes the very uppermost part of the mantle, which is liquid and mobile, but very stiff. The asthenosphere is composed of the mostly liquid mantle. The part of the mantle that makes up the asthenosphere is more fluid than the layer in the lithosphere, but it is less so than the inner mantle. (See References 4)

Mineral Composition

• The dominant substances that make up the lithosphere and the asthenosphere are different. There are more than 80 elements that appear in a huge variety of combinations within the lithosphere. (See References 5) The crust, the uppermost part of the lithosphere, is made up mostly of granite and basalt. (See References 6) The asthenosphere on the other hand, is composed primarily of ferro-magnesium silicates. (See Resources 1)