key term - Divergent boundary

Definition

A divergent boundary is a tectonic plate boundary where two plates move away from each other, creating new crust as magma rises to the surface. This process is crucial in forming mid-ocean ridges and rift valleys, significantly influencing geological features and activity on Earth. As these plates separate, they can lead to the formation of new oceanic crust and contribute to seismic activity.

5 Must Know Facts For Your Next Test

1. Divergent boundaries are primarily found along mid-ocean ridges, where tectonic plates are separating and creating new oceanic crust.
2. The East African Rift is a well-known example of a divergent boundary occurring on land, leading to the formation of rift valleys.
3. At divergent boundaries, magma rises to fill the gap created by the separating plates, resulting in volcanic activity.
4. Seismic activity at divergent boundaries is generally less intense than at convergent boundaries but can still result in earthquakes.
5. Divergent boundaries play a critical role in the rock cycle by continuously generating new lithosphere and recycling old materials.

Review Questions

• How do divergent boundaries contribute to the formation of geological features such as mid-ocean ridges and rift valleys?
  • Divergent boundaries play a crucial role in shaping geological features like mid-ocean ridges and rift valleys. As tectonic plates move away from each other, magma rises to fill the gap, forming new crust. This process not only creates mid-ocean ridges under the sea but also leads to rift valleys on land, exemplified by the East African Rift. These features are significant as they indicate active tectonic processes and can lead to volcanic activity.
• Discuss the relationship between seafloor spreading and divergent boundaries, highlighting its significance in plate tectonics.
  • Seafloor spreading occurs at divergent boundaries where two tectonic plates separate, allowing magma from the mantle to rise and create new oceanic crust. This process is significant in plate tectonics because it helps to explain how continents drift apart over geological time. As new material is added at mid-ocean ridges, it pushes older crust away, contributing to continental movement and ocean basin expansion. The ongoing process of seafloor spreading is fundamental to understanding Earth's dynamic surface.
• Evaluate the impact of divergent boundaries on global geological activity and their role in the rock cycle.
  • Divergent boundaries have a significant impact on global geological activity as they are sites of continuous creation of new lithosphere through processes like seafloor spreading. This ongoing formation of crust not only alters ocean basins but also affects global seismic patterns, although typically less violent than those associated with convergent boundaries. Furthermore, these boundaries contribute to the rock cycle by recycling old materials back into the mantle while producing fresh volcanic rock at the surface, thus playing a vital role in maintaining Earth's geological balance.

Related terms

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

Seafloor Spreading:

The process by which new oceanic crust is formed at divergent boundaries and gradually moves away from the ridge.

Rift Valley: A lowland region that forms where tectonic plates move apart, often associated with continental divergence.