Divergent boundary

Definition

A divergent boundary is a type of tectonic plate boundary where two plates move away from each other, leading to the creation of new crust as magma rises from the mantle. This movement typically occurs along mid-ocean ridges, where the upwelling of magma forms new oceanic crust, and can also lead to rift valleys on land. The activity at divergent boundaries is a crucial component in understanding plate tectonics and geodynamics, as it helps drive the continuous recycling of Earth's lithosphere.

5 Must Know Facts For Your Next Test

1. Divergent boundaries are often associated with volcanic activity due to the upwelling of magma that creates new crust.
2. The Mid-Atlantic Ridge is one of the most famous examples of a divergent boundary, separating the Eurasian and North American plates.
3. At divergent boundaries, earthquakes can occur as the plates pull apart and create tension in the surrounding rock.
4. Rift valleys, such as the East African Rift, form when continental plates diverge and create large cracks in the Earth's crust.
5. Divergent boundaries play a vital role in the process of plate tectonics, influencing ocean basin formation and continental drift.

Review Questions

• How do divergent boundaries contribute to the geological features of mid-ocean ridges?
  • Divergent boundaries contribute to mid-ocean ridges by facilitating the movement of tectonic plates apart. As these plates separate, magma from the mantle rises to fill the gap, creating new oceanic crust. This process not only forms the underwater mountain ranges characteristic of mid-ocean ridges but also influences the shape and topography of ocean basins, contributing significantly to Earth's geology.
• What is seafloor spreading and how is it related to divergent boundaries?
  • Seafloor spreading is the process that occurs at divergent boundaries where new oceanic crust is generated as tectonic plates move apart. This process begins at mid-ocean ridges, where magma rises and solidifies, pushing older crust away from the ridge. Seafloor spreading is essential for understanding how oceans expand over time and how continental drift occurs as plates continue to shift.
• Evaluate the impact of divergent boundaries on both oceanic and continental landforms.
  • Divergent boundaries significantly impact both oceanic and continental landforms through processes like seafloor spreading and rifting. In oceans, these boundaries lead to the formation of mid-ocean ridges and new oceanic crust. On continents, they can result in rift valleys characterized by steep walls and volcanic activity. The ongoing movement at these boundaries also shapes ecosystems and influences climate patterns as landforms evolve over geological timescales.

Related terms

Mid-Ocean Ridge: An underwater mountain range formed by plate tectonics, where new oceanic crust is created at divergent boundaries.

Seafloor Spreading:

The process by which new oceanic crust is formed at mid-ocean ridges and gradually moves away from the ridge, driven by tectonic activity.

Rift Valley: A lowland region formed by the divergence of tectonic plates on land, characterized by steep walls and often associated with volcanic activity.