1. EARTHQUAKES

2. INTRODUCTION TO EARTHQUAKES Earthquake = a vibration of the Earth produced by the release of energy. Seismology is the study of earthquakes and seismic waves that move through and around the earth. A seismologist is a scientist who studies earthquakes and seismic waves

3. What is the epicenter and focus of an earthquake? Energy that creates an earthquake moves out from the focus. The focus is the place within the Earth where the rocks breaks, producing an earthquake. The epicenter of an earthquake is the point on the ground’s surface directly above the focus.

4. Waves associated with earthquakes Energy moving outward from the focus of an earthquake travels in the form of seismic waves.

5. TYPES OF SEISMIC WAVES The two main types of seismic waves are body waves and surface waves. Body Waves Surface Waves

6. HOW DO SCIENTISTS MEASURE EARTHQUAKES There are two ways in which scientists quantify the size of earthquakes: magnitude and intensity Earthquake magnitudes are measured using the Richter Scale.

7. WHERE ARE EARTHQUAKES MOST COMMON? No part of the Earth’s surface is safe from earthquakes. But some areas experience them more frequently than others. Earthquakes are most common at plate boundaries, where different tectonic plates meet. The largest events usually happen where two plates are colliding- this is where a large amounts of stress can build up rapidly About 80 percent of all recorded earthquakes occur at the circum-Pacific seismic belt, commonly known as the Rim of Fire due to the prevalence of seismic and volcanic activity

8. Other facts about Earthquakes put together… Tectonic earthquakes are most common Earthquake is in other words, a shaking or trembling of the earth that accompanies rock movements extending anywhere from the crust to 680 km below the Earth's surface. The tsunami that hit Indonesia and killed more than 150,000 people would be measured at 9.0 in Richter Scale. Earthquakes release stress which causes permanent change in the Earth's crust.