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.

You might also be interested in:

Cool It! Game

Check out our online store - minerals, fossils, books, activities, jewelry, and household items!...more

Plate Tectonics

Many forces change the surface of the Earth over time. The largest force that changes our planet's surface is movement of Earth's outer layer in a process called plate tectonics. As shown in this picture,...more

What Is an Earthquake?

The ground underfoot might seem like it's not going anywhere but it is. It moves. If it moves all of a sudden the ground shakes. That's an earthquake! Earthquakes happen as pieces of the Earth's crust...more

Exploratour - The Archean Age

Meanwhile the seeds of continents called the "continental shields" began to take shape. The material which makes the continents is lighter and more bouyant than other crustal material, somewhat like the...more

Clues to Plate Movements

Many kinds of surface features are clues to a sliding lithosphere. Two types of features can form when plates move apart. At ocean ridges, the crust splits apart to make room for molten mantle rock. Continental...more

Mid-Ocean Spreading Ridge

As the Earth cools, hot material from the deep interior rises to the surface. Hot material is red in this drawing, under an ocean shown in blue green. The hotter material raises the nearby layers, and...more

Basalt Rocks

Basalt is volcanic rock. It is the most common type of rock in the Earth's crust and it makes up most of the ocean floor. It forms when lava reaches the Earth's surface at a volcano or mid ocean ridge....more

Elements in the Earth’s Crust

What’s the Earth made of? Most of the Earth’s outer layer, the crust, is made up of eight types of elements. Oxygen (O) Silicon (Si) Aluminum (Al) Iron (Fe) Calcium (Ca) Sodium (Na) Potassium (K) Magnesium...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA