Divergent boundary

Definition

A divergent boundary is a tectonic plate boundary where two plates move away from each other, creating new oceanic crust as magma rises from the mantle. This process is crucial for understanding seafloor spreading, as it leads to the formation of mid-ocean ridges and the expansion of ocean basins over time.

5 Must Know Facts For Your Next Test

1. Divergent boundaries are primarily found along mid-ocean ridges, where the ocean floor is continuously being created.
2. At divergent boundaries, the upward movement of magma leads to volcanic activity and the formation of new rock.
3. As plates separate, the gap allows magma to fill in, causing the seafloor to spread and create younger oceanic crust.
4. Divergent boundaries can also occur on land, such as the East African Rift, where continental plates are splitting apart.
5. The movement at divergent boundaries is generally slow, typically a few centimeters per year, but it can significantly affect the landscape over millions of years.

Review Questions

• How do divergent boundaries contribute to the process of seafloor spreading?
  • Divergent boundaries contribute to seafloor spreading by allowing tectonic plates to move apart. As these plates separate, magma rises from the mantle to fill the gap, creating new oceanic crust. This ongoing process leads to the formation of mid-ocean ridges, where new material is constantly added to the ocean floor, making it a key component in understanding how ocean basins expand over time.
• What geological features are commonly associated with divergent boundaries, and how do they impact oceanic geology?
  • Divergent boundaries are commonly associated with mid-ocean ridges and rift valleys. These features result from the constant creation of new oceanic crust as magma emerges from the mantle. The presence of mid-ocean ridges not only shapes the ocean floor but also influences ocean currents and marine ecosystems. The geological activity at these boundaries contributes to a dynamic and ever-changing oceanic environment.
• Evaluate the role of divergent boundaries in Earth's tectonic processes and their long-term implications for continental configurations.
  • Divergent boundaries play a crucial role in Earth's tectonic processes by facilitating seafloor spreading and contributing to the movement of tectonic plates. Over millions of years, this movement can lead to significant changes in continental configurations as landmasses drift apart or come closer together. The continuous creation and destruction of crust at these boundaries not only reshape the Earth’s surface but also influence geological events like earthquakes and volcanic eruptions, highlighting their importance in understanding Earth's dynamic nature.

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 divergent boundaries, contributing to the widening of ocean basins.

Tectonic Plates: Large slabs of Earth's lithosphere that move and interact at their boundaries, leading to geological phenomena such as earthquakes and volcanic activity.