DRRR

• Liquefaction


  The sediment composition becomes liquefied in the sense that it assumes the dynamics of water by flowing
• Liquefaction process


  Ground shaking causes sediments to flow like water due to disturbance
• Land-subsidence or the sinking of ground


  Attributed to various man-made activities such as the over-pumping of groundwater and many others
• Earthquakes and their complexities

  May cause land-subsidence, specifically earthquake-induced ground subsidence
• Liquefaction process


  Loose deposits of soil are compacted due to ground shaking, thereby causing the ground to subside
• Tsunami


  A wave or series of waves in a wave train generated by the sudden, vertical displacement of a column of water
• Causes of tsunami


  • Seismic activity
  • Explosive volcanism
  • Landslide above or underwater
  • Asteroid impact
  • Certain meteorological phenomena
• Tsunami


  Waves generated in oceans, bays, lakes, rivers or reservoirs
• Tsunami


  The term comes from the Japanese term "tsu," which means harbor and "nami" which means wave
• Tsunami


  Often develop a resonant phenomena in harbors after offshore earthquakes
• Tsunami


  Another name for harbor wave as it is seen near the harbor just before it causes a major catastrophe
• Tsunami of seismic origin

  1. Starts from a movement or slip of a fault underneath the ocean

  2. This movement is also described as a displacement, it makes the initiation of the tsunami
• Distant tsunami


  Heads toward the deep ocean
• Local tsunami


  Heads towards near the shoreline
• Tectonic plate subduction


  1. Tectonic plates move and collide

  2. Subduction zone forms
• Magma formation


  Water reduces melting point of rocks underneath, causing magma to form
• Lahar


  Indonesian term for lava or lava flow, adapted by volcanologists to describe a wet cement-like mixture of volcanic material and water
• Lahar flow


  Carries fresh volcanic materials - pyroclastic flows and tephra falls (ashfalls)
• Lahar


  • Highly mobile, spanning a movement speed of tens of meters per second, making it impossible to outrun by people
• Gray appearance of lahar


  Attributed to the presence of debris from ashfall
• Tephra


  Another name that refers to ashfall
• Ashfalls


  • Fragmented volcanic particles less than 2 mm in diameter
• Tephra


  Fragmented volcanic particles in general
• Pyroclastic flows


  Come from explosions
• Pyroclastic density currents (PDCs)


  Materials released from the mouth of the volcano, made up of volcanic particles, hot gases, and ashes
• Pyroclastic Flow


  • Dense type of current that moves a bit slower than a surge, more attached to the ground
• Pyroclastic Surge


  • Diluted type of current that has more mobility, posing more risk to affected communities
• Ballistic projectiles


  Large blocks of bombs formed from volcanic eruptions
• Water Vapor


  Colorless, odorless, and harmless gas released from volcanic eruptions, most abundant volcanic gas
• Carbon Dioxide (CO2)


  Colorless and odorless; most dissipate into the atmosphere; however, large concentrations released from a volcanic eruption fall and get trapped in low-lying areas; breathing air with more than 3% CO2 can quickly lead to headaches, dizziness, increased heart rate, and difficulty breathing; at mixing ratios exceeding about 15%, carbon dioxide quickly causes unconsciousness and death
• Sulfur Dioxide (SO2)


  Colorless gas with a pungent odor that irritates the eyes, skin, and respiratory system; high concentrations may create smog, which can cause further damage to communities, directly within the path of the wind
• Hydrogen Sulfide (H2S)


  Colorless, flammable gas with a strong, offensive odor and strongly associated with the smell of rotten eggs or sewer systems; mixing ratios above 0.01% H2S becomes odorless and very toxic, causing irritation of the upper respiratory tract and pulmonary edema during prolonged exposure; exposure to 500 ppm can cause a human to fall unconscious in 5 minutes and die in less than an hour or less
• Hydrogen Halides


  Toxic acids such as Fluorine (HF), Chlorine (HCI), and Bromine (HBr) that quickly dissolve in the atmosphere becoming components of acid rain; poisonous to sources of drinking water and vegetation