Divergent Plate Boundaries

"Two roads diverged in the wood..." - Robert Frost

Slowly Moving Apart

A divergent boundary occurs when two tectonic plates move away from each other. While most commonly found at the bottom of oceans, this boundary type can occur on land as well.

Earth's Landforms Created by Divergent Boundaries

  • New crust is formed at divergent boundaries. When the plates move apart, they open a rift valley or gap. Magma rises from the mantle into the gap and hardens into solid rock, forming new crust.
  • Sea-flooring spreading is a common phrase associated with divergent boundaries since this kind of boundary is typically at the bottom of oceans.
  • Mid-ocean ridges form when the magma overflows the crack and mounds up on either side because it is underwater and cools quickly. It is common to have rift valleys right down the middle of mid-ocean ridges.
Divergent Boundary

Divergent Boundary - Ocean/Ocean

  • A divergent boundary between 2 oceanic plates.
  • Most common divergent boundary
  • Landforms created: mid-ocean ridges, sea-floor spreading

Divergent Boundary - Continent / Continent

  • A divergent boundary between 2 continental tectonic plates
  • Less common than ocean/ocean
  • Landforms created: large rift valleys.
Divergent Plate Boundary Identification

Earth's Examples of Divergent Boundaries

  1. Mid-Atlantic Ridge is the largest continuous divergent ridge on earth and was first discovered in the middle of the Atlantic Ocean's sea-floor. It's discovery helped form the Plate Tectonic Theory.
  2. Great Rift Valley of Africa is a beautiful example of a continent/continent divergent boundary and helps explain the odd shape of Africa's east coast
  3. The rift valley system in Iceland almost splits the island in half since it sits directly on top of the divergent boundary between the North American plate and the Eurasian plate. Iceland itself can credit the divergent boundary for its formation in the first place.