Divergent boundary

Definition

A divergent boundary is a type of plate boundary where two tectonic plates move away from each other, leading to the formation of new crust as magma rises to the surface. This movement can create features such as mid-ocean ridges and rift valleys, playing a crucial role in the dynamic processes of the Earth's lithosphere.

5 Must Know Facts For Your Next Test

1. Divergent boundaries are primarily found along mid-ocean ridges, where they form long underwater mountain ranges.
2. The process of seafloor spreading at divergent boundaries contributes to the expansion of ocean basins over time.
3. As tectonic plates separate at divergent boundaries, earthquakes can occur due to the release of stress along faults.
4. Divergent boundaries can also form on land, leading to rift valleys like the East African Rift, showcasing significant geological activity.
5. The formation of new crust at divergent boundaries is essential for the recycling of the Earth’s lithosphere and maintaining tectonic balance.

Review Questions

• How do divergent boundaries contribute to the formation of mid-ocean ridges and what are their implications for ocean basin evolution?
  • Divergent boundaries play a key role in forming mid-ocean ridges as tectonic plates pull apart. This movement allows magma from the mantle to rise and solidify, creating new oceanic crust. As this process continues over time, it leads to the widening of ocean basins and contributes to geological features such as volcanic islands and underwater mountains, influencing the overall structure and dynamics of oceanic environments.
• Compare and contrast divergent boundaries with convergent boundaries in terms of geological activity and landforms created.
  • Divergent boundaries are characterized by tectonic plates moving apart, leading to the creation of new crust and features like mid-ocean ridges and rift valleys. In contrast, convergent boundaries occur when plates collide, resulting in subduction zones or mountain ranges. While divergent boundaries typically exhibit volcanic activity related to new crust formation, convergent boundaries often experience intense geological activity such as earthquakes and volcanic eruptions due to the recycling of crust.
• Evaluate the long-term effects of seafloor spreading at divergent boundaries on global tectonic processes and Earth's geological history.
  • Seafloor spreading at divergent boundaries has profound long-term effects on global tectonic processes by driving plate movements that shape Earth's geological history. This continuous process creates new oceanic crust while old crust is recycled back into the mantle at convergent boundaries. The balance between these processes contributes to plate tectonics' cyclical nature, influencing continental drift, climate changes over millions of years, and even biological evolution through altering habitats and creating new ecological niches.

Related terms

Mid-ocean ridge: An underwater mountain range formed by plate tectonics, where tectonic plates are moving apart and new oceanic crust is created.

Rift valley: A lowland region that forms where tectonic plates move apart on land, often characterized by steep walls and geological activity.

Seafloor spreading: The process through which new oceanic crust is formed at mid-ocean ridges as magma rises from below the Earth's surface, pushing tectonic plates apart.