drrr

• Islands and mountains in the Philippines were the result of the collision of the Pacific Plate in the east and the Eurasian Plate in the west
• Fault lines


  Cracks on the Earth's surface along which smaller plates move or slip against each other
• Tsunami is a series of large waves resulting from the disturbance of seawater commonly due to an earthquake, with wave heights reaching five meters or higher
• Liquefaction takes place when there is an increase in water pressure in saturated soil because of ground shaking
• Movement of active faults can be shown by fault slips based on displaced rocks or soil of known age, or through displaced landforms
• Ground Shaking is caused by the passage of seismic waves beneath structures, leading to tilting, splitting, toppling, or collapsing of structures
• Focus and Epicenter

  The place where the energy is released like an explosion is called the focus, while the epicenter is the point that is immediately above the focus (Cramer, 1991)
• Earthquake


  The weak or violent shaking of the earth's surface caused by the sudden movement of rock materials beneath it
• Ground subsidence or the lowering of the land surface can occur due to various reasons such as extraction of groundwater, natural gas, mining, and earthquakes
• As the Pacific Plate was forced against the Eurasian Plate, the crust crumbled
• Effects of Earthquakes

  • Ground Shaking
  • Ground Rupture
  • Liquefaction
  • Ground Subsidence
  • Tsunami
• Signs of an approaching local tsunami include a felt earthquake, extreme lowering of sea level, noticeable rise and fall of coastal water, and the rumbling sound of approaching waves (DOST-PHIVOLCS, n.d.)
• Ground Rupture is the displacement of the ground due to the violent shaking of the surface, which can be vertical or horizontal
• PHIVOLCS defines an active fault as a fault that has moved within the last 10,000 years, indicating historical seismicity