SCIENCE6 : 4TH QUARTER REVIEWER

• Epicenter

  The point below the surface of Earth where the trembling started
• Fault


  Fracture lines or cracks in Earth's surface that are caused by the movement of plates
• Tectonic earthquake


  Sudden movement of the rocks below the surface of Earth that causes an earthquake
• Earthquake


  a weak to violent shaking or trembling of the ground caused by the sudden movement of the rocks below the surface of Earth
• Earth's surface


  • Composed of a solid material called the crust
  • Made up of plates (also called tectonic plates) that resemble a giant puzzle
• How an earthquake occurs


  1. Plates bump side, or slip

  2. Huge rocks form at their edges

  3. Pressure builds up

  4. Rocks suddenly break or slip along a fault
• Types of earthquakes

  • Tectonic
  • Volcanic
  • Collapse
  • Explosion
• Tectonic earthquake


  Caused by sudden movements along the tectonic faults and plate boundaries
• Volcanic earthquake


  Caused by volcanic activities, such as rising magma of lava beneath active volcanoes
• Collapse earthquake


  Small quakes that occur in caverns or mines, often caused by underground blasts during mining operations
• Explosion earthquake


  Result from the explosion of a nuclear or chemical material or device
• Seismology


  The study of seismic waves, or energy waves that cause earthquakes
• Seismograph


  An instrument used to detect and record earthquakes
• Types of seismic waves

  • Primary waves (P-waves)
  • Secondary waves (S-waves)
  • Surface waves
• Magnitude


  Measure of the size of the seismic waves recorded in the seismograph, using the moment magnitude scale (MMS) or Richter scale
• Intensity


  Measure of the strength of the earthquake based on the observed effects on humans, animals, and physical structures
• Earthquakes at magnitude 3 or more can be felt by humans
• The intensity of an earthquake is generally near the epicenter
• Aftershocks


  Smaller earthquakes that follow the main shock fault
• Foreshocks


  Smaller earthquakes that precede a larger earthquake in the same location
• In the Philippines, the Philippine Institute of Volcanology and Seismology (PHIVOLCS) operates 101 seismic monitoring stations all over the country to detect and record earthquakes
• Magnitude refers to the size of the seismic waves that are recorded in the seismograph. Moment magnitude scale (Richter Scale) is used by scientists to measure the magnitude of an earthquake. Intensity of an earthquake is the strength of the earthquake based on the observed effects on humans and animals, as well as on the physical structures and properties within the area. The intensity is represented by Roman nerals. The intensity of an earthquake is generally near the epicenter.
• Strike-slip fault

  
• Reverse fault

  
• Normal fault

  
• What is magnitude?


  Refers to the size of the seismic waves that are recorded in the seismograph
• What is strike slip fault?


  Occurs horizontally due to horizontal shearing forces
• There are about 20 plates in the earth‘s crust
• When there is an undersea earthquake, a tsunami happens
• The location where an earthquake originated underground is called the focus.
• The scientific study of earthquakes and their phenomena is called seismology
• Tectonic earthquakes are caused by sudden movements of tectonic faults and plate boundaries
• Volcanic earthquakes are caused by volcanic activities
• Collapse earthquakes are small quakes that occur in caverns or mines
• A volcano is an opening in Earths crust that erupts when pressure builds up
• Cinder cone volcanoes have circular or oval cones made up of fragments or particles of lava expelled from a single vent that have been blown into the air
• Composite volcanoes are volcanoes that have steep sides, although they are shaped like cones. They are formed from many layers of volcanic rocks or lava for many years
• Shield volcanoes look like a shape or a bowl or a shield, with long gentle slopes made from basalt lava flows
• The lava that flows from shield volcanoes are called flood basalts
• Lava dome volcanoes are formed by thick lava, which makes a steep sided mound as the lava piles up near the vent of the volcano