KTTM+2.2

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2.2 Measuring Earthquakes
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Vocabulary
Moment magnitude scale**: a rating system that estimates the total energy released by an earthquake
 * Focus**: the point beneath Earth's surface where rock that is under stress breaks, which causes an earthquake to occur
 * Epicenter**: the point on the surface directly above the **focus**
 * Seismic waves**: vibrations that travel through Earth carrying energy released during an earthquake
 * Primary waves**: earthquake waves that compress and expands the ground like an accordion **( p waves)**
 * Secondary waves**: earthquake waves that vibrate from side to side as well as up and down **( s waves)**
 * Surface waves**: these waves move slower than **P waves** and **S waves** but they produce the most severe ground movement
 * Seismograph**: a graph that records the ground movements caused by **seismic waves**
 * Magnitude**: the measurement of earthquake strength based on seismic waves and movement along faults
 * Mercalli scale**: a device that was created to try to rate earthquakes according to their intensity
 * Richter scale**: a rating of the size of **seismic waves** which is measured by a particular type of mechanical **seismograph

Seismic Waves

 * Primary waves
 * Secondary Waves
 * Surface Waves

Detecting Seismic Waves

 * people used a seismograph to record the waves
 * the **seismograph** would draw lines on a paper to see how much force the **seismograph** is

Measuring Earthquakes

 * The **Mercalli Scale**
 * a creation that might not of worked
 * The **Richter Scale**
 * people still use this rating
 * The **Moment Magnitude Scale**
 * this scale can scale any earthquake even if it's very far away or very close

Locating the Epicenter

 * p waves come first and then s waves
 * the farther away the earthquake, the farther the p wave is to the s wave

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