Divergent Boundaries

Contributor: Meghan Vestal. Lesson ID: 11122

If the floor you are on would suddenly split apart what would happen? What happens when Earth's plates separate? Do we fall into holes? Learn from a helicopter and graham crackers to see what happens!

categories

Earth Science

subject
Science
learning style
Visual
personality style
Beaver
Grade Level
Middle School (6-8)
Lesson Type
Quick Query

Lesson Plan - Get It!

Audio:

What happens when Earth’s plates separate? Are people swallowed by giant holes in the earth?

In the previous Related Lesson, found in the right-hand sidebar, you learned what happens when tectonic plates collide.

On a separate piece of paper, draw a picture of a convergent boundary. Then, write a few sentences explaining what a convergent boundary is and what happens when plates converge. Have a teacher or parent check your work.

In this lesson, you will learn about another type of tectonic plate movement.

  • What is the opposite of two objects converging?

Think about the opposite of a convergent boundary.

  • What would happen at this boundary?

Discuss your ideas with a teacher or parent.

The opposite of a convergent boundary is a divergent boundary.

According to Merriam-Webster, diverge means "to split and move out in other directions." This is exactly what occurs at a divergent boundary. Rather than moving toward one another, the tectonic plates move away from one another.

Like convergent boundaries, the effects of a divergent boundary depend on where it takes place.

A divergent boundary that occurs on the ocean floor can create a mid-ocean ridge, or mountain range, along the ocean floor. As the plates pull away from one another, a ridge is formed when magma from within the earth rises to the surface. The magma does not pour out all over the ocean floor. As the magma rises to the surface, it quickly cools, forming a new layer of rock.

The Mid-Atlantic ridge is one of the most well-known examples of a divergent boundary. Visit The Geological Society's webpage, Mid-Atlantic Ridge, to learn more about this famous divergent boundary. Be sure to watch the video on the page to see how boundary was formed.

Divergent boundaries that form on land create rifts, or cracks, in the earth. If the rift occurs near a body of water, it can fill with water. Other times, magma rises to the earth's surface, creating a volcano. Watch Photovolcanica's video Lava Fountains from Bardarbunga Volcano Holuhraun Fissure Eruption viewed by Helicopter Flights (below):

 

  • Can you see the rift created by the divergent boundary?

Discuss what you observe with a teacher or parent.

To learn more about divergent boundaries, read Geology.com's article, Divergent Plate Boundaries.

tectonics

Image courtesy of U.S. National Park Service and is, therefore, in the public domain.

 Look at the map above.

  • Where do you see examples of divergent boundaries?
  • Is there an increase in earthquakes in these locations?
  • Do you live near a divergent boundary?

Discuss your responses with a teacher or parent.

Review the questions from the beginning of the lesson.

  • What happens when the earth's plates separate?
  • Are people swallowed by giant holes in the earth?

Discuss your responses with a teacher or parent, then continue on to the Got It? section to prepare for a hands-on project.

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