Layers Of The Earth - Earth Sciences Flashcards
What are the four layers of the Earth?
Crust, mantle, outer core, inner core.
What is the crust?
The crust is the very thin, hard, outer layer of the planet. It is split into plates, and is also called the lithosphere. It includes landforms, rocks and soil.
What state is the crust in?
The crust is in a solid state.
How thick is the crust?
Oceanic crust is 5-10km thick, while continental crust is 35-70km thick.
Why is the crust important?
It is where all life on earth exists, and protects life from the magma in the mantle.
What is the mantle?
The mantle is a deep layer of molten rock below the crust, and contains a lot of different rock types.
What state is the mantle in?
The mantle is mostly made up of molten rock. It is not liquid, but it is also not solid (“solid but flows”).
How thick is the mantle?
The mantle is 2900km thick.
Why is the mantle important?
It contains large amounts of heavy metals and generates convection currents, which move the tectonic plates.
What is the outer core?
The outer core is the third layer of the Earth, and is mostly made up of iron.
What state is the outer core in?
The outer core is molten iron.
How thick is the outer core?
The outer core is from 2900-5200km thick.
Why is the outer core important?
The outer core is important is important because it generates the Earth’s magnetic field, which protects the Earth from solar wind and cosmic radiation.
What is the inner core?
The inner core is the innermost layer of the Earth, and is made up of iron.
What state is the inner core in?
The inner core is a solid ball of iron. It is solid because it has the pressure of the other layers pushing down on it.
