EARTHQUAKE

• Earthquakes


  The shaking and trembling caused by the sudden release of energy.
• Earthquakes


  Associated with faults. When a fault suddenly moves, an earthquake occurs.
• Seismology


  Study of Earthquakes
• Seismologist


  Scientist who studies Earthquakes
• PHIVOLCS

  Philippine Institute of Volcanology and Seismology
• Fault


  A fracture in the rocks that make up the Earth’s crust.
• Epicenter


  The point at the surface of the Earth above the focus.
• Plates/Fault Scrap


  Massive rocks that make up the outer layer of the Earth’s surface and whose movement along faults triggers earthquakes.
• Seismic Waves


  Waves that transmit the energy released by an earthquake.
• Focus(Hypocenter)


  The point within the Earth where an earthquake rupture starts.
• Magnitude


  It is the energy released by an earthquake at the focus. It is calculated from earthquakes recorded by an instrument called seismograph.
• Intensity


  It is the strength of an earthquake perceived and felt by people in a certain locality. It is generally higher near the epicenter.
• Fault


  A break or a fracture in the earth's crust, and along the break, significant movement has taken place.
• Three types of fault:

  Normal Fault, Reverse Fault, Strike-Slip Fault
• Normal Fault


  The rock layers in the earth's crust are pulled apart, and gravity causes on section to move downward in relation to the other.
• Reverse Fault


  The rock layers in the earth's crust are squeezed together and the force pushes one section upward in relation to the other.
• Strike-Slip Fault


  Forms when the rock layers on opposite sides of a fault slides past each other horizontally.
• How do faults produce quakes?

  Friction - The resistance to motion of one object moving relative to another.
• Philippine Fault Line


  The longest fault in the Philippines that stretches up to 1,200 kilometers from Luzon down to Mindanao.
• West Valley Fault


  Starts near Angat, Bulacan, in the north. It extends through parts of the provinces of Rizal, Cavite, and Laguna before terminating near Calamba, Laguna, in the south.
• Earthquake


  It is a vibration of the Earth due to the rapid release of energy.
• Focus


  The place where the earthquake starts.
• Epicenter


  The spot on the surface of that is directly above the focus.
• Magnitude


  Strength/Energy of an earthquake
• Intensity


  The strength of the movement of an earthquake (how strong or weak is the shaking.)
• Seismograph measures ground vibrations produced during an earthquake.