____________ are vibrations that travel through the Earth. They are caused by big events like earthquakes and explosions.

This person studies earthquakes.

This is a hot (slow moving) solid layer of Earth between the crust and the core.

What is the idea that continents move around on Earth's surface?

__________________ is a theory explaining how tectonic plates move on Earth's surface.

The center of the Earth is the _____________.

An ancient (very old) super-continent is....

In the picture, the core is the....

In the picture, the blue part is the _______________.

In a __________ boundary, a tectonic plate boundary with two plates moving apart (in different directions).

In a ______________ boundary, two plates come together (move toward each other).

With a ___________________ boundary, two plates slide (move) by each other.