REVIEW: The Spheres

The Spheres

Photo courtesy of Aschaf/Flickr. Licensed CC BY.

The Earth has several different "spheres:"

• Atmosphere: parts of the Earth above the geosphere, extending upward to space. This includes the air you breathe.
• Biosphere: parts of the Earth where living organisms exist; the sum of all ecosystems.
• Geosphere: parts of the Earth where rocks and soil are present.
• Hydrosphere: parts of the Earth where water is present.

Each of these spheres interacts with one another in a million different ways. There is also a lot of overlap between spheres. For example, the ocean is included in both the hydrosphere (the water itself) and the geosphere (the ocean floor). Clouds are included in both the hydrosphere (water droplets that form the clouds) and the atmosphere (because they are located above the surface of the Earth).

After you have completed this part of the lesson, you can check the associated box on the main course page to mark it as complete