The asthenosphere is the upper zone of the Earths mantle, located below the lithosphere, approximately between 30 and 130 kilometers deep. It is composed of solid and semi-fused materials that allow the continental drift development and the isostasys. The asthenosphere is responsible for promoting the renewal and expansion of the ocean floor. The characteristics of the asthenosphere are:

• Composition: The asthenosphere is composed of semi-fused and solid materials at the same time. It is formed by iron and magnesium silicates, which is almost identical to the lower layer of the earth or mesosphere.

• Viscosity: The asthenosphere is a region of partially molten rock, which allows this layer to flow very slowly. Its properties, characterized by partial melting and a degree of ductility, enable the movement of tectonic plates, playing a vital role in the process of plate tectonics.

• Movement: The asthenosphere can flow by deforming like a plastic and carries tectonic plates. Due to the temperature and pressure conditions in the asthenosphere, rock becomes ductile, moving at rates of deformation measured in cm/yr over lineal distances eventually measuring thousands of kilometers. In this way, it flows like a convection current, radiating heat outward from the Earths interior.

In summary, the asthenosphere is a semi-fluid layer located in the upper part of the Earths mantle, situated beneath the lithosphere. It is composed of solid and semi-fused materials that allow the continental drift development and the isostasys. Its properties, characterized by partial melting and a degree of ductility, enable the movement of tectonic plates, playing a vital role in the process of plate tectonics.