The Earth consists of 3 layers that comprise its structure:
- Crust
- Mantle
- Core [ Inner Core & Outer Core ]
Some people consider Core as two layers i.e. Inner Core & Outer Core. So according to them earth has four layers.
Each of these layers has unique properties including composition, temperature, thickness and quality of matter that give each an identity. Let’s get into more details about Earth’s structure and description and features of each layer of Earth.
Layers of Earth : Explanation
Inner Core:
Inner core is Earth’s hottest layer, located deep below its surface in its core region at its center. Composed primarily of nickel and iron, its inner region can experience temperatures as high as 5,500 C(9,932 F).
Even with extreme temperatures, Earth’s core remains solid due to massive pressure from outer layers which forces metal atoms to stay together [ compress] . This prevents the core region from melting into liquid form.
Outer Core:
Outside the inner core lies an outer core made up primarily of melting metals such as nickel and iron. This outer core extends approximately 1800 miles (2,900 km) below the earth’s surface and the thickness of this layer is around 1400 miles (2,250 km).
Temperatures range between 4,000 F-9,000 F (2,200 C to 5,000 C), making this metal hot enough to reach liquid state and completely displace its solid inner core with fluid metal that continually changes direction due to rotation.
Liquid metals moving within this layer create a magnetic field around Earth via geodynamo effect, producing its magnetic field.
The magnetic field provides protection from harmful solar radiation, helping keep our planet safe.
Transfers heat from the inner core to the mantle, driving convection currents.
The Mantle:
The mantle is by far the largest and thickest layer on Earth with approximately 2,650 kilometers (1,800 miles) below the Earth’s Crust. It makes up about 84% of Earth’s total volume and consists of semi-molten rock known as magma.
Mantles can be divided into two distinct layers :
Upper Mantle : The rocks found here are strong and hard, forming part of the lithosphere (which includes Earth’s crust).
Lower Mantle : As depth increases, the temperature rises, and the rocks become softer and partially melted, allowing them to flow slowly over long periods.
Crust [ Earth’s Outer Shell ]
The outer layer of Earth is where life exists and it is the only layer where life can thrive. The thickness of the layer “Crust” varies between zero and 60 km (0 37 miles to 60 miles). Composed mainly of solid rock material that varies depending on where it lies; composition can change according to geographic area and environment. Natural resources including water, minerals, and fossil fuels are available here.
Types of Crust:
Continental Crust comprises largely of granite. It covers large land masses. It is generally thicker (35 to 70 kilometers).
Oceanic Crust is found under oceans. It is very thin when compared to Continental Crust (5 to 10 kilometers thick) and comprises basalt.
Lithosphere (crust and mantle upper) is responsible for volcanic eruptions, earthquakes and mountain development.
For easy understanding of Earth’s structure, you can assume Earth as a boiled egg.
Eggshell = the crust.
Egg white = The mantle
Soft yolk = The outer core
Solid center of the yolk = The inner core.
Conclusion : Hope the above article gives you a clear insight on Earth’s structure and its layers.