layers of Earth

• The Earth consists of three layers: core, mantle, and crust.
• The solid outer layer is the crust.
• A semi-molten rock called magma lies in the mantle below the crust.
• Beneath the mantle is the core
• The outer core is a liquid mixture of nickel and iron while the inner core is solid.
• The crust is a very thin layer that measures between 0 and 60 km.
• It has two layers and is composed of two major kinds of rocks. The thick continental crust, about 32 km, makes up the land surface of the Earth and is composed primarily of dense materials such as granite. The thin oceanic crust has a depth of 5–10 km and is made up of basalt which is less dense than granite.
• The crust can be broken down into plates which produce earthquakes when they move along each other.
• The mantle is below the crust. It is the thickest layer of the Earth, spanning almost 2900 km and making up 84% of the Earth’s volume. It contains magma.
• It is primarily solid but behaves as a viscous liquid. (Mantle)
• This behavior is due to temperature differences towards the lower mantle. As the depth becomes near the core, the temperature increases. This is known as the geothermal gradient, the increase in temperature with depth.
• In the upper mantle, the temperatures range from 600 to 900 °C. In the lower mantle, the temperature can reach over 4000 °C.
• Convection currents carry heat from the hot inner mantle to the cooler outer mantle. If the upper part of the mantle cools down, it becomes part of the crust. Also, this process is responsible for earthquakes and other geological processes.
• lithosphere, a zone of rigid, brittle rock.
• This part of the mantle is solid in a plastic manner (flows very slowly), allowing the plates to move on top of it. (asthenosphere)
• The core is at the center of the Earth. In this region, the temperature is hotter than the mantle.
• The liquid outer core is 2300 km thick. It is composed primarily of iron and nickel. The temperature here is around 4000–5700 °C. Due to its high temperature, the outer core undergoes convection and rotates faster than the planet.
• The inner core is a solid ball with a radius of 1220 km. Like the outer core, the inner core is made up of iron and nickel, but in solid form. The temperature is quite high at around 7000 °C.
• What is the difference between the state of matter of the inner and outer core? (high pressure in inner core)
• Scientists believed that the inner core rotates opposite to the direction of the flow of the outer core, creating an effect that influences the Earth’s magnetic field.