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The Spring 2011 issue of The Earth Scientist is focused on modernizing seismology education. Thanks to IRIS, you can download this issue for free as a pdf. Print copies are available in our online store.
This drawing shows the Earth's lithosphere (crust and upper mantle) on top of the asthenosphere.
Click on image for full size

The Earth's Crust, Lithosphere and Asthenosphere

The crust is the upper layer of the Earth. Under the oceans it is only about 5 km thick while under the continents it can be up to 65 km thick.

The plates that fit like puzzle pieces around the Earth are made of Earth’s crust and the upper part of the mantle layer. Together the crust and upper mantle are called the lithosphere and they extend about 80 km deep.

These plates move a little bit each year as they slide on top of a layer in the mantle called the asthenosphere. This layer can be pushed and deformed like silly putty, flowing because of the warmth of the Earth. The flowing asthenosphere carries the lithosphere including the continents, plants, animals and you on its back. All this moving rock can cause earthquakes.

Last modified May 21, 2008 by Lisa Gardiner.

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