Book 1, Question 57 · Video
Why Do Earthquakes Happen? Slipping Slabs of Rock!
Earthquakes begin deep underground when huge slabs of rock called plates move very slowly. Sometimes the plates get stuck at a fault while the force keeps pushing, so stress builds
Read the full answer →What Crafty Clover says in this video
Intro
Hi! I'm Crafty Clover! Let's discover something amazing. Why do earthquakes happen?
The Big Idea
Have you ever felt the ground shake? That's an earthquake! Earthquakes happen deep underground, when huge slabs of rock suddenly move.
Plates Creep
Step one: Earth's plates creep. The outside of our planet is cracked into giant pieces of rock called plates. They move very slowly, just a few centimeters a year. That's about as fast as your fingernails grow!
Stress Builds
Step two: they snag, and stress builds. Where two plates meet, their rough edges can get stuck. That crack is called a fault. But the force keeps pushing, and pushing. Stress builds up in the rock, like a stretched rubber band!
Waves Race Out
Step three: rock slips, and waves race out. When the stress gets too big, the rock suddenly slips! All that stored energy races out through the ground as seismic waves. That's what makes the ground shake!
A Closer Look
Let's take a closer look inside an earthquake! Here are two plates, pushing past each other. The zigzag crack between them is the fault, where the rock snags and slips. And these rings are seismic waves, spreading out in every direction, like ripples in a pond.
Quick Facts
Quick facts! Most big earthquakes happen at plate edges, where the stress is greatest. Scientists measure earthquakes with machines called seismometers. Earth has thousands of tiny earthquakes every day. Most are too small to feel! The spot on the surface right above a quake is called the epicenter.
Think Like a Scientist
Now, think like a scientist! Grab two books. Push their spines together. Keep pushing, harder and harder, until one slips. What happens? Did they jump suddenly? That's just like rock slipping along a fault! Be curious, and keep exploring!
Outro
Earthquakes happen when stuck plates finally slip, and send waves racing through the ground! Keep asking, keep exploring! Crafty Clover can be found on Amazon Books, Google Bookstore, and Apple Books. Available for purchase or download! Bye for now!