What is the name given to a boundary where tectonic plates are spreading apart?

The boundary where tectonic plates are spreading apart is known as a divergent plate boundary. This type of boundary is characterized by the tectonic plates moving away from each other, which often results in the formation of new oceanic crust as magma rises to the surface. An example of a divergent boundary is the Mid-Atlantic Ridge, where the Eurasian and North American plates are moving apart, allowing magma to create new ocean floor.

In contrast, convergent boundaries occur where plates move towards each other, often resulting in one plate being forced beneath another, leading to subduction zones and mountain formation. Transform boundaries involve plates sliding past one another horizontally, causing seismic activity without the creation or destruction of crust. Subduction zones are specifically areas of convergent boundaries where one plate sinks beneath another. The terminology around these boundaries is vital in understanding the dynamic processes of Earth's lithosphere.