Table of Contents Earthquake 4 Moving Parts 8 Plate Boundaries 16 Forces Folds and Faults 24 Seismic Waves 32 Be Prepared 40 How You Can Help When Disaster Strikes 45 Glossary 46 Index 47 Show What You Know 47 Websites to Visit 47 About the Author 48
Earthquake The ground shakes suddenly It’s an earthquake The layers of rock deep inside Earth are on the move When the Earth shakes below the surface it can cause major damage above The ground below us is always moving An earthquake can happen at any time of the year It can happen anywhere You can’t stop an earthquake but you can learn what to do when one happens near you The 1994 Northridge earthquake caused the collapse of this freeway overpass in Los Angeles 4
US Earthquakes 1900 2013 Magnitude 3 5 5 0 5 0 5 5 5 5 6 0 6 0 Depth 0 69 km 70 299 km 300 700 km Alaska Hawaii Puerto Rico This map shows earthquakes in the United States from 1900 to 2013 Earthquakes have been recorded all across the United States Some quakes are small and are barely noticed Big earthquakes on the other hand get everyone’s attention In 1994 an earthquake in Los Angeles caused apartment buildings to collapse At the Northridge Meadows apartments the entire first floor crumpled The second floor fell down to the ground level The third floor became the second floor Sixteen people died after the Northridge Meadows apartments collapsed in the 1994 Northridge earthquake 5
