DRRR FINALS REVIEWER

• Velocity


  The product of frequency and amplitude of a seismic wave
• Acceleration


  The rate of change of velocity expressed as a ratio of the acceleration of gravity
• Frequency


  How often a vibration occurs, measured in hertz (Hz) or cycles per second
• Wavelength and frequency


  Their product is the velocity
• Period (Duration)


  The time (in seconds) it takes for one full cycle to occur, equal to the reciprocal of frequency (1/frequency)
• Natural frequency


  The frequency at which a system naturally vibrates once it has been set into motion, depends on the stiffness and mass of the system
• A g value of 0.001 is perceptible by people while 0.1 g is sufficient to produce some damage to weak construction
• The building code of the Philippines contains guidelines about the required g (acceleration) values for building design and construction
• Ground shaking per se cannot harm you if you are in an open field
• Normal fault


  • Involves mainly downward movement of the ground across the fault called hanging wall
• Thrust fault


  • Involves mainly upward movement of the hanging wall
• Strike-slip fault


  • Involves a dominantly shifting of the ground
• Ground ruptures


  Earthquake faults that have reached the surface
• Ground shaking or vibration


  What we feel when energy built up by the application of stress to the lithosphere is released by faulting during an earthquake
• Fault


  A fracture on which one body of rock slide past one another
• Elastic rebound theory


  1. Elastic strain energy builds up in the deforming rocks on either side of the fault until it overcomes the resistance posed by any irregularity on the fault plane

  2. When the slippage does occur energy is released

  3. The elastic energy released is transported by seismic waves that travel throughout the earth

  4. We feel these seismic waves as vibrations
• Landslides - occur when soil becomes saturated with water and loses its cohesion due to heavy rainfall or rapid snowmelt.
• Tsunami - is a series of ocean waves generated by sudden displacement of water on the seafloor.
• Tectonic - Earthquake produces by sudden movement along faults and plate boundaries
• Volcanic - Earthquake produces by sudden movement of magma beneath volcanoes
• Intensity - it is the perceived strength of an earthquake
• Magnitude - based on instrumentally derived information and correlated strength
• Secondary waves - This is a body wave with low frequency and can only pass through rocks
• Primary waves - The fastest seismic wave and are the first to reach any particular location after an earthquake occurs
• Secondary waves - These seismic waves move along the earth's crust and make the ground roll up and down or shake from side to side
• 0.1 - This g value is sufficient to produce some damage to weak construction
• Liquefaction - Takes place when loosely packed, water logged sediments at or near the ground surface lost their strength in response to strong ground shaking
• Strike - slip fault - Involves a dominantly horizontal shifting of the ground
• Types of Liquefaction features:

  1. Ground oscillation
  2. Settlement
  3. Flow Failure
  4. Lateral Spread
  5. Loss of Bearing Strength
• Types of Landslides

  TOPPLES - Type of landslide that occur suddenly when massive part of every steep slopes loose and rotate forward
• Types of Landslides

  • ROCK FALLS - a landslide that involve chunks of detached rock that fall freely for some distance or bounce and roll down the steep slope
  • LATERAL SPREADS - a landslide that are triggered by earthquakes and affect gentle slopes with less than 10 degrees inclination. Slope materials lose cohesion through liquefaction caused by shaking during earthquake
  • FLOWS - Type of landslide that involve downslope motion of fine-grained clay, silt, and fine sand made mobile by water saturation. These flows include mudflows and earthflows, and are common during the rainy season
  • SLIDES - a landslide that involve large blocks of bedrock that break free and slide down along a planar or curved surface
  • COMPLEX SLIDES - a landslide which are combination of two or more types of movements
• ROCK FALLS


  Type of landslide that involve chunks of detached rock that fall freely for some distance or bounce or curved surface
• FLOWS


  Type of landslide that involve downslope motion of fine-grained clay, silt, and fine sand made mobile by water saturation. These flows include mudflows and earthflows, and are common during the rainy season
• TOPPLES


  Type of landslide that occur suddenly when massive part of every steep slopes loose and rotate forward
• LATERAL SPREADS


  Type of landslide that are triggered by earthquakes and affect gentle slopes with less than 10 degrees inclination. Slope materials lose cohesion through liquefaction caused by shaking during earthquake
• SLIDES


  Type of landslide that involve large blocks of bedrock that break free and slide down along a planar or curved surface
• Landslide


  The downslope movement of rock, soil and mud
• Tsunami


  A sea wave of local or distant origin that results from large-scale seafloor displacements associated with earthquakes, major submarine slides, or exploding volcanic islands
• Risk Management


  The systematic approach and practice of managing uncertainty to minimize potential harm and loss
• Risk Assessment


  A methodology to determine the nature and extent of risk by analyzing potential hazards and evaluating existing conditions of vulnerability that together could potentially harm exposed people, property, services, livelihood, and the environment on which they depend