Divergent plate boundaries

Definition

Divergent plate boundaries are geological features where two tectonic plates move away from each other, creating new crust as magma rises from the mantle to fill the gap. This process is a key aspect of plate tectonics and contributes to the formation of mid-ocean ridges and rift valleys. At these boundaries, the upwelling of magma not only leads to seafloor spreading but also influences volcanic activity and earthquake occurrences in these regions.

5 Must Know Facts For Your Next Test

1. Divergent plate boundaries are primarily found along mid-ocean ridges, which are the longest mountain ranges in the world, mostly located underwater.
2. The movement at divergent boundaries can result in volcanic activity, as the rising magma creates new crust, often leading to the formation of volcanoes at these locations.
3. Earthquakes are common along divergent boundaries due to the tension and friction created as tectonic plates pull apart.
4. The process of seafloor spreading not only creates new oceanic crust but also contributes to the age distribution of ocean floors, with newer crust found at the ridge and older crust further away.
5. Divergent plate boundaries play a crucial role in recycling Earth's lithosphere, influencing ocean basin formation and continental drift over geological time.

Review Questions

• How does seafloor spreading occur at divergent plate boundaries, and what geological features are associated with this process?
  • Seafloor spreading occurs at divergent plate boundaries when tectonic plates move apart, allowing magma from the mantle to rise and solidify as new oceanic crust. This process creates geological features such as mid-ocean ridges, where the crust is continuously formed and pushed outward. As a result, the seafloor expands, contributing to the development of distinct geological structures like volcanic islands and underwater mountains.
• Discuss the relationship between divergent plate boundaries and earthquake activity, including how this relates to plate tectonics.
  • Divergent plate boundaries are characterized by the movement of tectonic plates away from each other, which leads to the creation of new crust. The tension and friction between these plates can cause stress to build up, eventually resulting in earthquakes. While earthquakes at divergent boundaries are generally less intense than those at convergent or transform boundaries, they still play a significant role in understanding tectonic activity and the dynamic nature of Earth's lithosphere.
• Evaluate the significance of divergent plate boundaries in terms of global geological processes and their impact on Earth's surface features.
  • Divergent plate boundaries are essential for understanding global geological processes such as seafloor spreading and continental drift. Their role in creating new oceanic crust not only reshapes ocean basins but also influences climatic patterns and biodiversity in marine environments. Additionally, these boundaries lead to the formation of unique geological features like rift valleys and mid-ocean ridges, which serve as vital ecosystems. The interplay between divergent boundaries and other tectonic processes highlights their significance in shaping Earth’s geology over millions of years.

Related terms

Mid-ocean Ridge: An underwater mountain range formed by the upwelling of magma at divergent plate boundaries, where new oceanic crust is created.

Seafloor Spreading: The process by which new oceanic crust is formed at mid-ocean ridges as tectonic plates diverge, causing the ocean floor to expand.

Rift Valley: A lowland region that forms where tectonic plates diverge on land, characterized by steep walls and often associated with volcanic activity.