Describe divergent boundaries.
Divergent boundaries are regions where tectonic plates are moving away from each other. The movement of the plates creates a gap or space between them, which is filled by the upwelling of molten material from the Earth's mantle. This process is known as seafloor spreading.
At divergent boundaries, new crust is constantly being formed as the molten material cools and solidifies, creating new oceanic crust in the case of underwater divergent boundaries or new continental crust in the case of continental divergent boundaries. This continuous creation of crust causes the plates to move apart, often resulting in the formation of a mid-ocean ridge or rift valley.
The presence of divergent boundaries is often associated with volcanic activity, as the molten material can erupt onto the ocean floor or the land surface. This volcanic activity contributes to the formation of new landforms, such as volcanic islands or volcanic mountain ranges.
One well-known example of a divergent boundary is the Mid-Atlantic Ridge, which runs through the center of the Atlantic Ocean. It marks the boundary between the Eurasian and North American plates. The Great Rift Valley in East Africa is another famous example, where the African Plate is splitting apart, forming a large valley.
Divergent boundaries play a significant role in the theory of plate tectonics and the movement of Earth's lithospheric plates. They create new crust, drive the process of seafloor spreading, and contribute to the geological activity and landforms we observe on Earth.