Earth's structure
Earth's Structure
Inner Core
- The inner core is the central part of the earth.
- It is mostly composed of iron and nickel, giving it strong magnetic properties.
- Pressure at the inner core is extremely high - about 3 million times atmospheric pressure.
- Despite the high temperatures (up to 5700°C), the inner core is solid due to immense pressure exerted on it.
Outer Core
- Surrounding the inner core is the outer core.
- This is a layer of molten iron and nickel. Its temperatures range between 4000°C and 5700°C.
- The outer core is responsible for the creation of Earth's magnetic field through a process known as the dynamo effect.
Mantle
- Above the outer core lies the mantle, the thickest layer of the Earth.
- It's divided into the upper mantle and the lower mantle, each with different geological properties.
- The mantle is composed mostly of silicate rocks, rich in iron and magnesium.
- The upper layers of the mantle mix with the plates of the crust, forming a region called the asthenosphere.
Crust
- The uppermost layer of the earth is called the crust.
- It is relatively thin compared to the other layers, with depths ranging from 5km to 70km.
- Two types of crust exist: the oceanic crust (density around 3.0g/cm³) and the continental crust (density around 2.7g/cm³).
- The crust is mainly comprised of silicate rocks and is broken up into numerous tectonic plates.
Lithosphere
- The lithosphere is the rigid outermost shell of a planet.
- Earth's lithosphere includes the crust and the uppermost mantle.
- The lithosphere is broken into a number of tectonic plates that float on the semi-fluid asthenosphere beneath.