Divergent Boundary

Definition

A divergent boundary is a tectonic plate boundary where two plates move away from each other, leading to the formation of new crust as magma rises to the surface. This process is primarily associated with mid-ocean ridges and rift valleys, resulting in geological features such as volcanoes and earthquakes. Divergent boundaries are significant in the context of plate tectonics and geologic processes because they are responsible for the recycling of the Earth's crust and the dynamic nature of its surface.

5 Must Know Facts For Your Next Test

1. Divergent boundaries are commonly found along mid-ocean ridges, where new oceanic crust is formed as tectonic plates separate.
2. The movement of plates at divergent boundaries can lead to shallow earthquakes due to the tension created as the plates pull apart.
3. Magma rising through divergent boundaries often results in volcanic activity, contributing to the formation of new landforms.
4. The East African Rift is a notable example of a divergent boundary on land, where tectonic forces are pulling the African continent apart.
5. Divergent boundaries play a crucial role in the Earth's rock cycle by facilitating the creation and recycling of crustal materials.

Review Questions

• How does a divergent boundary contribute to the formation of geological features such as mid-ocean ridges and rift valleys?
  • A divergent boundary contributes to geological features like mid-ocean ridges and rift valleys by allowing tectonic plates to move apart. As the plates separate, magma rises from below the Earth's crust to fill the gap, creating new crust. This process forms underwater mountain ranges known as mid-ocean ridges and can also create rift valleys on land, where the ground sinks and fractures due to the pulling apart of tectonic plates.
• Discuss the relationship between divergent boundaries and seafloor spreading, including its significance in plate tectonics.
  • Divergent boundaries are directly related to seafloor spreading, which occurs as tectonic plates move apart at these boundaries. When plates separate, magma rises to fill the void, creating new oceanic crust that pushes older crust away from the ridge. This process is significant because it not only generates new seafloor but also influences global tectonic activity, contributing to continental drift and shaping ocean basins over time.
• Evaluate the environmental impacts of divergent boundaries on ecosystems and geological formations over time.
  • The environmental impacts of divergent boundaries on ecosystems and geological formations can be profound. As new crust forms at mid-ocean ridges or rift valleys, it alters habitats and can create new ecological niches. Additionally, volcanic eruptions associated with divergent boundaries can affect climate patterns and atmospheric conditions. Over time, these processes contribute to landscape evolution, promoting biodiversity through the creation of varied habitats while also posing risks such as earthquakes and volcanic hazards for nearby communities.

Related terms

Mid-Ocean Ridge: An underwater mountain range formed by the upwelling of magma at divergent boundaries, creating new oceanic crust.

Rift Valley: A lowland region that forms where tectonic plates are pulling apart, characterized by steep walls and volcanic activity.

Seafloor Spreading:

The process by which new oceanic crust is created at divergent boundaries as magma rises and solidifies, causing the seafloor to expand.