4 EarthquakesEarthquakes transfer stored energy into kinetic energy in form of seismic waves.These waves are MECHANICAL wavesWaves are an oscillation or vibration that transfers energy
5 Earthquake Identification and Location Earthquakes are located and identified by their focus, epicenter and magnitudeFocus: The point where the fracture in rock occurs, (under ground).Epicenter: The point, on land, directly above the focus point.Magnitude: The amount of energy or destruction that has been released/caused
8 Explain the difference between a Focus and an Epicenter? If earthquakes are mechanical waves, what are the other types of waves called?
9 MagnitudeRichter Scale: Measures the total amount of energy released by the earthquake.Magnitude 7 or greater is a major quakeMagnitude 6 or less is a minor quakeMagnitude 2 or less is a micro quake or tremor
10 Magnitude Continued 2. Mercalli Scale: Measures the degree of destruction that has been caused. This is a scale that is far more subjective in nature.Mercalli scale rates on a scale of I – XII(I) is little damage and (XII) is extreme destruction
11 Seismic Waves Primary or P waves Secondary or S waves Fastest moving seismic waveArrive at recording stations firstMoves in a spring like wayTravel through both liquid and solid materialSlower moving waveArrives at recording stations after the P waveMoves in an up and down wayCause buildings to shakeTravels through solid material only
12 Primary and Secondary Waves P waves oscillate through compression and expansion, in the same direction of movementS waves oscillate in a direction that is perpendicular to direction of movement
13 L-Waves L waves are also known as surface waves They are the slowest but most destructive wavesThey are the waves that cause surface rolling
14 Which is the fastest moving seismic wave? Which seismic wave is most destructive?
15 Distance to EpicenterSeismologists determine the distance to the earthquake’s epicenter through analyzing the difference in arrival times at the recording station.When arrival times are close, with little difference, the distance to the epicenter is very small.The greater the difference in arrival times, the further away the epicenter isUse information from 3 recording stations to triangulate the location