MLEG2.2

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Vocabulary
Focus : the point under Earth that starts an earthquake

Epicenter : the point that is right under the focus of an earthquake

Seismic waves : traveling vibrations (that travel through Earth)

Primary waves (P waves) : a type of wave from an earthquake that expands and compresses

Secondary waves (S waves) : a type of wave from an earthquake that shakes up-to-down or side-to-side

Surface waves : a wave that forms when S waves+P waves reach Earth's surface

Seismograph : moves the ground up and down or side to side

Magnitude : measurement of an earthquake's strength depending on waves and movement around faults

Mercalli Scale : a machine that rates an earthquake according to their strength

Richter Scale : rates earthquakes according to the size of their seismic waves

Moment Magnitude Scale : rating system that guesses the total power given by an earthquake

Outline
Seismic Waves Detecting Seismic waves Measuring Earthquakes Locating an epicenter
 * P waves
 * primary waves
 * are the first to arrive at seismograph station
 * compress or expand the ground
 * buildings: contract and expand
 * S waves
 * secondary waves
 * reach surface and things start shaking violently
 * cannot move through liquid
 * shakes side-to-side or up-and-down
 * Seismograph
 * records ground movement
 * mechanical and electronic types of seismograph
 * will show different heights
 * Mercalli Scale
 * rate earthquakes based on intensity
 * describes earthquakes affecting people,buildings, and land surfaces
 * not a precise measurement
 * Richter Scale
 * rating size of seismic waves
 * used for 50 years
 * provides accurate movement even for the smallest earthquakes
 * Moment Magnitude Scale
 * rates estimate of total energy produced by an earthquake
 * study data in a seismograph first, then the Moment Magnitude Scale
 * 5.0: small, above 5.0: large
 * epicenter
 * farther earthquakes, bigger time
 * draw at least three circles
 * point where circles intercept is the epicenter