The composition of Earth consists of three main divisions: Core, mantle, and crust. The crust is the outermost layer of the Earth. It makes up less than 1 percent of the Earth’s radius. The mantle is the middle layer which constitutes 68 percent of the Earth’s composition. The core is the innermost layer of the Earth’s structure. It makes up 31 percent of the Earth’s radius.
Layers of the Earth Surface
Crust
The outer surface of the Earth is known as the crust. The crust makes up less than 1 percent of Earth’s radius. The crust is of two types depending upon their physical and chemical properties. They are oceanic crust and continental crust. The oceanic crust is composed of magma that erupts on a seafloor. Igneous, metamorphic and sedimentary rocks made continental crust.
Oceanic crust
The magma that erupts from seafloor cools down to create intrusive igneous rocks. The sediments are thickest near the shore. The mud and shells of the tiny creatures coat the seafloors. Therefore, deposits are most abundant near the shore when it comes off the continents.
Continental crust
The igneous, metamorphic, and sedimentary rocks make up the continental crust. The continental crust rises higher than the oceanic crust because it is thick and has low density.
Mantle
Mantle makes up 68 percent of the Earth’s composition. Its features are that it is made up of solid rocks from seismic waves, heat flow, and meteorites, and it is hot. The mantle is very hot due to the heat flowing outward. Heat flows in two ways within the Earth known as convection and convention. Conduction refers to the heat transfer that occurs through the collision of atoms. Convection in the mantle is the same as convection in a pot of water on the stove. The core heats the bottom of the mantle, which leads to particles moving more rapidly.
Core
The core is made up of 31 percent of the composition of Earth. A core is said to be a metal. It is made up of nickel and iron. Metallic meteorites are representative of the core. The outer core is said to be liquid while the inner core is solid because S-waves stop at the inner core.
