Chapter 10 Section 2 Locating and Measuring Earthquakes

1. Chapter 10 Section 2Locating and Measuring Earthquakes Objectives: -Explain how a seismograph is used to record earthquake waves and locate an earthquake epicenter -Summarize how the magnitude of an earthquake is measured

2. Seismograph • An instrument that detects and records waves produced by earthquakes • Over 10,000 seismograph stations are operating around the world

4. Seismogram • A record of wave activity produced by a seismograph • Because P waves travel faster than S waves, P waves are the first to be recorded

5. Interpreting a Seismogram

6. Locating Epicenters • Seismograms tell scientists the distance between the seismograph station and the epicenter, but not the exact location. This distance is actually a radius of a circle around the station. • So how can we determine the exact location of earthquakes?

7. Triangulation

8. Locating Epicenters

9. Measuring Earthquake Magnitude • Magnitude is a measure of the amount of energy released during an earthquake • Richter Scale