Earth's Crust

The crust, Earth’s thin outermost layer made of solid rocks, exists in two forms: continental and oceanic, covering the planet from land to sea.

Let’s start with the continental crust, the part of Earth that forms the land we live on. It is the foundation for landforms like towering mountains and deep valleys.

The continental crust is a thicker layer with an average thickness of about 22 miles.

This crust is made of lighter rocks like granite and is less dense, allowing it to float on the mantle and raise continents above the oceanic crust.

Now, let’s dive beneath the oceans to the oceanic crust. This form of the crust is only 3 to 8 miles thick.

The oceanic crust is made of dark, heavy rocks like basalt, which form when lava erupts and cools on the ocean floor.

These dense rocks make the oceanic crust sink deeper into the mantle than the lighter continental crust.

The Earth’s surface not only extends unevenly beneath sea level but also rises into the atmosphere.