Our class in Environmental Engineering, our professor told us the land portion of the earth. 30% of the earth is composed of land, and the remaining 70% is water. Our earth is composed of three main layers, the core or the inner layer, the mantle and the crust which includes the continent and the ocean floor. Lithosphere is the rigid outermost shell of a rocky planet. On earth, it comprises the crust and the portion of the upper mantle that behaves elastically on time scales of thousand of years or greater.
In our earth, lithosphere includes the crust and the upper most mantle, which represent the hard and rigid layer of the earth. Asthenosphere, the hotter and deeper part of the upper mantle. The boundary between the lithosphere and asthenosphere is defined by a difference in response to stress; the lithosphere remains very rigid for very long periods of geologic time; while asthenosphere deforms viscous and accommodates strain through plastic deformation. The Lithosphere is broken into tectonic plates.
