Print

Science

Changes to the Earth and its atmosphere

The Earth has a layered structure, including the corecore: The core is the innermost part of the Earth., mantle [mantle: A zone of hot rock in the interior of the Earth, located between the outer crust and the molten core. ] and crust [crust: The outer layer of the Earth, on top of the mantle. It is between 6 and 48 kilometres thick and includes the continents and the ocean floor. ]. The crust and upper mantle are cracked into large pieces called tectonic plates. These plates move slowly, but can cause earthquakes and volcanoes where they meet.

The Earth’s atmosphere has changed over billions of years, but for the past 200 million years it has been much as it is today.

The structure of the Earth

The outer-most layer is called the crust. The crust surrounds the mantle, which surrounds the core. There are 2 parts to the core - the outer core and the inner core, which is the inner most part of the Earth's structure.

Cross section showing structure of the Earth

The Earth is almost a sphere. These are its main layers, starting with the outermost:

  1. crust - relatively thin and rocky
  2. mantle - has the properties of a solid, but can flow very slowly
  3. outer core - made from liquid nickel and iron
  4. inner core - made from solid nickel and iron

Note that the radius of the core is just over half the radius of the Earth. The core itself consists of a solid inner core and a liquid outer core.

Back to Oils, Earth and atmosphere index

BBC navigation

BBC © 2014 The BBC is not responsible for the content of external sites. Read more.

This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.