EARTH DETECTIVES EXPLORING EARTHQUAKES SEISMOLOGISTS AT WORK Elsie Olson Consulting Editor Diane Craig M A Reading Specialist Super Sandcastle An Imprint of Abdo Publishing abdopublishing.com
EARTHQUAKES WHAT IS AN EARTHQUAKE An earthquake happens when parts of Earth shake Seismic waves cause this shaking These waves start deep inside Earth Quakes can occur anywhere But most happen at fault lines These are places where pieces of Earth’s crust fit together Sometimes the pieces slip past one another This causes a quake
