The foundation of the earth is composed of many layers, which include the core, mantle, and crust. The earths core is the central part of the system and is composed of two parts; the inner core and the outer core. The inner core is made up of solid iron and nickel and is a solid sphere. This layer is surrounded by the outer core which is composed of liquid iron and nickel. Together, they form a thick layer of iron, nickel, and other elements that reach temperatures up to 7000 degrees Celsius (McKie, 2009).
The mantle is the layer below the crust and is composed of dense rocks such as basalt. It is approximately 2,900 kilometers thick and is the source of most of the earths internal heat. The mantle contains the convecting structures that allow the circulation of magma, which is the molten rock material that exists beneath the surface of the earth. The mantle is divided into the upper mantle, containing the lithosphere, and the lower mantle, which is made up of hot semi-solid rock.
The earths crust is composed of a thin layer of rock that is less than five percent of the earths entire mass. This layer is primarily composed of oxygen, silicon and other elements. There are two types of crust; the continental and the oceanic. The continental crust is thicker and is composed of a lighter material. The oceanic crust is thinner, denser and is composed of a heavier material.
Plate tectonics is what drives the formation of the layers of the earth. The movement of the tectonic plates causes heat and pressure due to the friction of one tectonic plate moving past another. The movement of the plates also causes earthquakes as they move, which can cause major shifts in the layer of the crust. The formation of mountains and valleys is also caused by the movement of the plates.
The layer of the earths foundation has been continuously changing over time, due to the forces at work within the Earths mantle. It is estimated that the Earths core is billions of years old, while the mantle and crust are continually being created and destroyed due to the movement of the plates. It is also believed that the Earths atmosphere and oceans are constantly changing due to weather patterns and ocean currents.
Although the earth is constantly changing, it has an incredible foundation that provides it with the stability and support it needs. The Earth is composed of many layers and each of them contribute to the foundation of the planet, enabling it to sustain life as we know it. The earths foundation helps keep the temperature, pressure and chemical composition of the atmosphere and oceans within tolerable limits. Without such a complex foundation, life as we know it could not have evolved on Earth.
