CSTC+2.2

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Vocabulary

 * Focus**: the point beneath Earth's surface where rock that is under stress breaks


 * Epicenter**: point directly above the focus


 * Seismic waves**: vibrations that travel through Earth's surface carrying the energy created by an earthquake


 * Primary waves**: the earthquake waves that compress and expand the ground like an accordion


 * Secondary waves**: the waves that vibrate from side to side as well as up and down


 * Surface waves**: when Primary waves and Secondary waves reach the surface some of them are transformed into Surface waves


 * Seismograph**: the instrument that geologist use to record and measure the vibration of seismic wave


 * Magnitude**: the measurement of earthquake strength based on seismic waves and movement a long faults


 * Mercalli Scale**: rate earthquakes by their intensity


 * Richter Scale**: rate earthquakes by mechanical seismograph


 * Moment Magnitude Scale**: rates earthquakes by estimating the total energy released

Outline

 * Seismic Waves**

-P waves compress and expands the ground -S waves vibrates the Earth side to side and up and down -Surface waves shake buildings side to side


 * Detecting Seismic Waves**

-seismograph


 * Measuring Earthquakes**

-Mercalli scale measures by intensity

-The Richter scale measures by a type of mechanical seismograph

-Moment magnitude scale estimates the total amount of energy released


 * Locating the epicenter**

-uses seismic waves