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 often occurs at mid-ocean ridges, creating new oceanic lithosphere, and can also be associated with rift valleys on continents. Divergent boundaries play a key role in the ongoing movement of Earth's plates and are essential in understanding geological processes and structures.

5 Must Know Facts For Your Next Test

1. Divergent boundaries are primarily found along mid-ocean ridges, which are the longest mountain ranges on Earth.
2. At divergent boundaries, the lithosphere is pulled apart, causing volcanic activity and earthquakes due to the movement of magma.
3. The rate of seafloor spreading at divergent boundaries can vary from a few millimeters to several centimeters per year.
4. Continental rifting can occur at divergent boundaries, leading to the formation of rift valleys, such as the East African Rift.
5. Divergent boundaries contribute to the recycling of Earth's crust as new material is created and older crust is pushed away.

Review Questions

• How does the movement of tectonic plates at divergent boundaries influence geological features?
  • The movement of tectonic plates at divergent boundaries leads to the creation of new geological features such as mid-ocean ridges and rift valleys. As the plates pull apart, magma rises from the mantle, forming new crust. This process results in volcanic activity and can also create significant geological formations like rift valleys when it occurs on land. Understanding this movement is crucial for recognizing how Earth's landscape evolves over time.
• Analyze the relationship between seafloor spreading and divergent boundaries in terms of oceanic crust formation.
  • Seafloor spreading occurs at divergent boundaries where tectonic plates move apart, allowing magma to rise and solidify at mid-ocean ridges. This process creates new oceanic crust while simultaneously pushing older crust away from the ridge. The continuous cycle of crust formation and displacement not only contributes to ocean basin expansion but also plays a critical role in global tectonic activity and plate movements.
• Evaluate the impact of divergent boundaries on continental geology and how they relate to broader tectonic processes.
  • Divergent boundaries significantly impact continental geology through processes such as continental rifting, which can lead to the formation of rift valleys and affect local ecosystems and human settlements. These boundaries highlight the dynamic nature of Earth's lithosphere and its contribution to broader tectonic processes like plate movement and earthquake activity. As plates diverge, they initiate cycles of creation and destruction that shape not only continents but also influence climate patterns over geological time scales.

Related terms

Mid-ocean ridge: An underwater mountain range formed by plate tectonics at divergent boundaries where new oceanic crust is created.

Seafloor spreading: The process that occurs at divergent boundaries, where new oceanic crust forms as magma rises and solidifies, pushing older crust away.

Rift valley: A lowland region formed by the downward displacement of a block of the Earth's crust, often occurring at divergent boundaries on land.