Earthquake Epicenter

• Earthquake


  Shaking and trembling of the Earth's crust caused by a sudden release of energy
• Earthquake occurrence


  Rocks along a fault line suddenly move
• Earthquake occurs


  Seismic waves are created
• Seismic waves


  Can cause tsunamis and fire which may lead to loss of life and huge damage to property
• Seismology


  Study of earthquakes and the waves they create
• Seismologists


  Scientists who study earthquakes
• Seismic waves


  Energy that is released is carried by a vibration
• Types of Body Waves

  • P-Waves (primary waves)
  • S-Waves (secondary waves)
• 1. P-Waves

  Travel faster than other seismic waves, first signal from an earthquake to be felt, can be transmitted through gases, liquids and solids
• 1. S-Waves

  Type of elastic wave, one of the two main types of elastic body waves, also called shear waves
• Types of Surface Waves

  • Love Waves
  • Rayleigh Waves
• Love Waves


  Have a horizontal motion that is transverse to the direction the wave is travelling, fastest surface wave, moves the ground from side to side
• Rayleigh Waves


  Move in an elliptical motion, producing both vertical and horizontal motions, moves the ground up and down and side to side in the same direction that the wave is moving
• Epicenter


  Location where the waves from an earthquake are highly intense, area where the most damage can possibly occur
• Locating the epicenter


  Determine the time interval between the arrival of the P and S waves (the S-P interval) on the seismograms from at least three different stations
• Earthquake cause


  Sudden slip on a fault, tectonic plates get stuck at their edges due to friction
• Fault


  Area where an earthquake occurs or where the surface slipped
• Hypocenter or focus


  Location below the earth's surface where the earthquake starts
• Epicenter


  Location directly above the hypocenter on the surface of the earth
• Earthquake magnitude


  Measurement of the maximum motion recorded by a seismograph, most commonly used are Local Magnitude (ML), surface wave magnitude (Ms), body-wave magnitude (Mb), and moment magnitude (MW)
• Richter Scale


  Used to measure earthquake magnitude
• Mercalli Scale


  Used to measure earthquake intensity
• Intensity


  Measure of the amount of earth shaking that happens at a given location
• Magnitude


  Measures the size of the seismic waves or the amount of energy released at the source of the earthquake
• Intensity Scale

  • 1 (not felt by many)
  • 2 (felt by few)
  • 3 (felt by few indoors)
  • 4 (felt by many indoors)
  • 5 (felt by almost everyone)
  • 6 (felt by all)
  • 7 (find damages to few buildings)
  • 8 (slight damage to specially designed structures)
  • 9 (destroys some well-built wooden structures)
  • 10 (destroys well-built wooden structures)
  • 11 (destroys bridges and railways)
  • 12 (Total Damage)
• Safety Precautions Before Earthquake

  • Prepare a fire extinguisher
  • Prepare a first aid kit
  • Have a battery powered radio
  • Have emergency light/flashlights with extra battery
  • Learn to turn off gas, electricity and water
  • Do not place heavy objects above head level
  • Make a plan where to meet with family
• Safety Precautions During Earthquake

  • Stay calm
  • If outdoors, stay in an open area far away from power lines or anything that might fall
  • If indoors, stay inside and observe the Drop-Cover-Hold protocol
  • Do not use elevators in high rise buildings
• Safety Precautions After Earthquake

  • Be prepared for aftershocks
  • Listen to radio or television for information
  • Check home for damages
  • Wear protective clothing and sturdy shoes