Earthquake 2nd qt

• Waves


  High frequency waves can travel only on solid mediums and all mediums
• S.waves

  • Rock masses move perpendicular to the direction of the waves
  • Produce the most damage to buildings, highways, and travel within the earth's interior
• Body waves move on the earth's interior
• Surface waves


  Move on the earth's exterior
• Types of seismic waves

  • P-waves
  • S-waves
  • L-waves
• 1. P. waves

  Primary waves, first to be recorded by a seismograph, can travel through all types of medium (solid, gas, liquid)
• 1. waves


  Secondary waves, second to be recorded by the seismograph, can only travel through solid mediums
• 1. waves


  Love waves and Rayleigh waves, slowest among the waves, exist on the free surface generated by large earthquakes, move the ground up, down, and side to side in a rolling motion
• Seismograph is used to detect, measure, and record seismic waves
• Seismogram


  Visual record of the severity of the earthquake from the focus and epicenter, used for measuring the time lag between the arrival of P and S waves
• Epicenter


  Where the earthquake starts
• Focus


  Fracturing of rocks, also called hypocenter
• Earthquake


  The moving of the ground, measured by magnitude and intensity
• Magnitude


  Strength and "size" of an earthquake
• Intensity


  How much the damage and effect is
• Modified Mercalli Intensity Scale (MMI)


  Classifies earthquake effects into 12 grades
• Richter Scale


  Developed by Charles Richter, an American Seismologist in 1935
• Tsunamis are huge waves caused by an earthquake that occurs underneath the ocean
• Tsunamis


  • Height can reach up to 30 or 100 feet in extreme cases
  • Speed exceeding 500 miles per hour (as fast as a jet flies)
• 90% of earthquakes happen in the Ring of Fire and 80% of the world's earthquakes also happen here
• 75% of the world's dormant volcanoes are also found in the Pacific Ring of Fire
• Crust


  Structures or breaks in the earth's crust that appear as cracks, including cracks on the oceanic floors
• Types of volcanoes

  • Cinder cone
  • Composite
  • Shield
• Tectonic fault


  Enables the collision, sliding, or separation of rock masses
• Types of tectonic faults

  • Compressional fault
  • Tensional fault
  • Shearing fault
• Reverse fault


  Formed when a rock mass in the crust is pushed up relative to the other rock mass due to compressional stress
• Normal fault


  Occurs when one rock mass moves downward relative to the other, forming a normal fault, in places that are highly elevated
• Transform fault


  Occurs when a rock mass on one side of a fault slides past the other, causing violent earthquakes
• Causes of tsunamis


  • Earthquakes
  • Landslides
  • Lava entering the sea
  • Meteorite impacts
• Geologists study the earth and its minerals, volcanoes, and the earth's external and internal activities
• Active volcano


  Erupts regularly
• Dormant volcano


  Only erupted once, but there is still a possibility that it will erupt again
• The Sergey Soloviev Medal is given to a person who has contributed greatly to the branch of science
• Countries near the equator, which are part of the Ring of Fire, are most likely to experience earthquakes and volcanic eruptions, which are more severe
• The Philippine Institute of Volcanology and Seismology (PHIVOLCS) is the government agency responsible for monitoring volcanoes, earthquakes, tsunamis, and other geological hazards.
• A magnitude scale measures the size or intensity of an earthquake based on its energy release.
• Seismographs measure the intensity of seismic waves generated by earthquakes.
• Richter Scale - Logarithmic scale used to measure the amplitude of seismic waves generated by an earthquake.
• Modified Mercalli Intensity Scale - Measures the effects of an earthquake on people and structures.