Hi! I'm Alora. And-

The ground shakes and a loud grumble comes from the Earth.

Woah! Did you feel that? THAT was an Earthquake!

An earthquake? Oh yeah! When the Earth's ground shakes and moves!

Oh, what tectonic plates?

That's right, grandma! An earthquake is when tectonic plates move and cause the Earth's ground to shake!

Ohhhhh-

Oh, they're the plates that are under us at the upper mantle. Their boundaries move against each other causing friction which is what starts an earthquake

WOOF!?

Woops, you're right Cory! I forgot that the plates actually move against each other in different ways! Let's take a look at the different ways!

Here, we can use these Rubiks Cubes as an example. We put them against each other to show how tectonic plates are always touching each other like this.

Now we add arrows to describe how they're moving. Right now they're pulling apart from each other like plates do. This is a divergent boundary! They cause the floor of the ocean to spread.

Now they're being pushed INTO each other. This is called a convergent boundary. This causes subduction which is when the denser plate slips under the less dense plate. In this case, the Rubiks cube to the right is denser.

Now they're sliding against each other in opposite directions! This is called a transform boundary. This causes lots of shallow earthquakes.

Those are all the ways that an earthquake can happen because of tectonic plates moving!

WOOOOFF!

What? Oh, well we know this because of a man named Alfred Wegner.

A long long time ago, Alfred Wegner was looking at the continents of the world and found that they look as if they all fit together like puzzle pieces. This gave him the idea that they were once all together...

Like a Super continent! So he brought this up to his boss at work

They all fit together! They were once a super contine-

Not enough evidence.

Oh right, but Alfred didn't have enough evidence except for the fact that they all fit together, so they classified his idea as a hypothesis, just an prediction rather than a theory which would be a more confirmed way.

We do know that already. Thanks to seismographs. 

Well how will we know how bad earthquakes are and remember what they do?