Fourth Grade
Worksheets
Whole Lotta Shakin' Goin' On!
Why is it that earthquakes always happen in California? Why don't they happen in Florida? To answer these questions, you will have to learn a little about the structure of the Earth. Our planet is made up of rock and metal. The Earth has many different layers. The top layer of the Earth is not one solid piece of rock. Instead, it is made up of many pieces that fit together. These pieces are called plates. The plates do not fit together like a puzzle, though. They are always moving. Sometimes they bump into each other. Other times they slide against each other or scrape together as they move. The plates are not smooth. They have rough edges and sometimes the plates get stuck together. The plates keep pushing harder and harder against each other until, finally, they move. This causes an earthquake. The ground shakes because of all .....
