The Earth's Crust

The crust is the outside layer of Earth. It is like the skin on an apple but much thinner compared to the rest. We live on the crust. It is made of hard rock and soil and holds the oceans and continents.

Two Types of Crust

There are two kinds of Earth's crust. Continental crust makes up the land where we live and is thicker. Oceanic crust lies under the oceans and is thinner but heavier. Oceanic crust is made of dark rock called basalt. Continental crust has lighter rock like granite.

Broken into Pieces

The crust is not one big piece. It is broken into huge sections called tectonic plates. These plates slowly move on top of the hot mantle below. When plates crash together or pull apart, they can cause earthquakes. They also help build mountains and volcanoes over millions of years.

Fun Facts

• The crust under the ocean is only about 5 miles thick in some places.
• Mount Everest sits on a thick part of continental crust.
• The crust is only about 1 percent of Earth's total mass.

Did You Know?

If Earth were the size of an apple, the crust would be thinner than the apple's skin.