Planet Earth is approximately 4,000 miles from the surface to the center. Earth is made up of different layers that all have specific conditions and a unique composition.
Earth's Crust
Is a thin shell on the outside of Earth, accounting for less than 1% of Earth's volume. The crust is the top part of an even bigger layer of Earth called the lithosphere which is a includes the outermost crust that we well know and the upper part of Earth's mantle beneath the crust. The lithosphere is broken very large sheets of rock called tectonic plates that move! This will be become a very important detail for future modules.
Oceanic Crust
- Oceanic crust is typically found under ocean waters, and it is approximately four miles thick in most places.
- Oceanic crust is relatively thin and more dense than continental crust.
Continental Crust
- Continental crust varies between 6 and 47 miles in thickness depending on where it is found. Continental crust tends to be much older than oceanic crust, and rocks found on continental crust are often the oldest in the world. Examples of such rocks are those in Quebec, Canada which are estimated to be about 4 billion years old.
- Continental crust is typically found above sea level, and is relatively thick compared to oceanic crust. Despite it's thicker nature it is far less dense than oceanic crust. This density difference will be very important in our study of the Earth later on.
Lithosphere
Is the rocky outer part of the Earth. It is made up of the brittle crust and the top part of the upper mantle. The lithosphere is the coolest and most rigid part of the Earth.
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Topic Tips
- The crust is the thinnest, least dense, solid layer of Earth.
- The crust is made up of oceanic and continental crust which make up the upper part of the lithosphere.