At divergent boundaries, the Earth's tectonic plates pull apart from each other. This contrasts with convergent boundaries, where the plates are colliding, or converging, with each other. Divergent boundaries exist both on the ocean floor and on land.
The Earth has several major tectonic plates, which are sections of unbroken crust. These plates are constantly moving and consist mainly of solid rock. Collectively, these plates create the outer shell of Earth, which is called the lithosphere. When the movement of the tectonic plates causes two plates to pull away from each other, a divergent boundary is said to exist.
Divergent boundaries that develop in the ocean lead to the creation of mountains and volcanoes, according to the National Geographic. This occurs because magma from deep within the Earth rises at the point of a divergent boundary and creates new crust.
When a divergent boundary occurs on land, it leads to the formation of a valley known as a rift. One example of a divergent boundary that is occurring on land is the Great Rift Valley. This divergent boundary is pulling the continent of Africa in two different directions. Eventually, this particular boundary is going to cause the continent to break apart into two separate land masses.