Plate Tectonic Boundaries

There are three types of plate tectonic boundaries and these all change the Earth's surface, as well as the ocean floor. Each type of plate boundary moves in a different way. On this post, we'll explore the three types of plate boundaries, how they move, and what happens as a result of their movement.

Divergent Boundary

The first kind of boundary we will look at is called a Divergent Boundary. If you look closely at the word, "Divergent",  you can almost see the part of the word, "Different"  in it. If you can remember that, it is helpful in remembering how these plates move. Because Divergent plates are like "different", I like to think that they don't get along because they are different and therefore they move apart. And that is exactly what Divergent boundaries do! Another word that might be helpful to trigger your memory is "Divide". As the plates are forced apart melted rock comes to the surface and hardens into new crust. The area between the two plates where the melted rock comes to the surface is called a rift valley. A large chain of volcanic mountains can form along the rift as the melted rock rises and cools into new rock.
Check out this short animation to see a divergent boundary.

Convergent Boundary

Another type of boundary is when plates come together or collide with each other. One plate is forced down and melted while the other is forced upward and folded into mountains. A trench is formed where the two plates meet. This is called a "Convergent Boundary".

 

This is a real-world example of a Convergent Boundary. See how the land in the middle of the picture is pushing up where the two sides meet? Pretty amazing!

Transform Boundary

The last type of boundary we'll look at is called "Transform" or "Sliding" boundary. The reason it is called this is because instead of the plates moving away from each other, or crashing into each other, the plates are sliding by each other, kind of like when you pass someone in the hallway. These plates slide along beside of each other. Since plate boundaries are not smooth, plates do not slide smoothly. The plates can suddenly break free of each other and cause powerful earthquakes. One of the most well known Transform Boundaries in the world is called "The San Andreas Fault", which is located in the state of California. California experiences many earthquakes each year because of this boundary, or fault zone. Notice the red arrows in this map of the San Andreas fault, which show the two land masses sliding beside each other.

 

Plate tectonics is fascinating to study. Check out this site for more information to understanding about plate tectonics.
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