EDR

• Volcano

  An opening in the earth's crust through which molten lava, ash, and gases are ejected. It is generally located in areas where the tectonic plates diverge or converge with each other.

  
• Vulcan

  An island in Italy and/or the God of Fire in the Roman Mythology
• Types of Volcano (Structure)

  • Shield volcano
  • Cinder cone volcano
  • Composite volcano
  • Caldera "giant" volcano
  • Fissure volcano

  
• Shield volcano


  • Built entirely or mostly from fluid lava vents, can measure for about hundreds of miles across and many tens of thousands of feet high

  
• Cinder cone volcano


  • Normally small about a miles span and about one thousand feet vertically, consist of mostly loose, grainy cinders and have very little to no lava

  
• Composite volcano


  • Also called "Strato Volcano", consist of lava that is mixed with sand or gravel which in turn creates cinders or volcanic ash

  
• Caldera "giant" volcano

  • Circular depressions in the ground over a magma chamber, easier to notice from space due to the distance and viewpoint

  
• Fissure volcano


  • Have no main crater, the ground just splits and lava pours out through the cracks, hard to recognize from the ground and sometimes from space

  
• Types of Volcano (Activity)


  • Active volcano
  • Dormant volcano
  • Extinct volcano

  
• Active volcano


  A volcano that has had at least one eruption during the past 10,000 years, the type of volcanoes that in general have been active for a certain period of time

  
• Dormant volcano


  Quiet volcanoes, but might possibly erupt again
• Extinct volcano


  Volcanoes are often considered to be extinct if there are no written records of its activity
• Types of Volcanic Eruption


  • Hawaiian eruption
  • Strombolian eruption
  • Vulcanian eruption
  • Pelean eruption
  • Plinian eruption
  • Icelandic eruption

  
• Hawaiian eruption


  Fluid basaltic lava is thrown into the air in jets from a vent or line of vents (a fissure) at the summit or on the flank of a volcano
• Strombolian eruption


  Eruptions involve moderate bursts of expanding gases that eject clots of incandescent lava in cyclical or nearly continuous small eruptions

  
• Vulcanian eruption

  A short, violent, relatively small explosion of viscous magma
• Pelean eruption

  Associated with explosive outbursts that generate pyroclastic flows, dense mixtures of hot volcanic fragments and gas

  
• Plinian eruption


  Caused by the fragmentation of gassy magma and are usually associated with very viscous magma

  
• Icelandic eruption


  From small effusive eruptions where lava flows quietly from fissures and crater rows to significant explosive eruptions in ice-covered central volcanos that produce large ash plumes

  
• Tsunami


  A series of waves generated when an oceanic body of water is rapidly disturbed because of an underwater earthquake, volcanic eruption, landslide or underwater explosion, and whose height could be greater than 5 meters
• Tsunamis are generated by earthquakes and tsunami waves are generated because

  
  

  movement of fault under the sea. The increase in wave heights associated or during typhoons (when there are strong winds) or tropical cyclones are called "storm surges"
• Types of Tsunami

  • Local tsunamis
  • Far field or distant tsunamis

  
• Local tsunamis

  Confined to coasts within a hundred kilometers of the source usually earthquakes and a landslide or a pyroclastic flow, can reach the shoreline within 2 to 5 minutes

  
• Far field or distant tsunamis


  Can travel from 1 to 24 hours before reaching the coast of the nearby countries

  
• PTWC (Pacific Tsunami Warning Center) and NWPTAC (Northwest Pacific Tsunami Advisory Center) are the responsible agencies that closely monitor Pacific-wide tsunami event and send tsunami warning to the countries around the Pacific Ocean

  
• Signs of Tsunami


  • Shake (earthquake)
  • Drop (water recede or rise)
  • Roar (unusual sound)
  • Outdoor tsunami warning sirens and messages
  • Emergency alert phone calls and text messages
  • Television and radio warning broadcasts

  
• Shake (earthquake)


  If the ground shakes under your feet in a coastal region, a tsunami may have been caused by a strong undersea earthquake

  
• Drop (water recede or rise)


  Before a tsunami arrives, water may recede from the shoreline before returning as a fast-moving wall of water

  
• Roar (unusual sound)


  If you hear a loud roar approaching (a bit like a passenger jet or a train), it could be a tsunami approaching

  
• When you get a tsunami warning, go immediately to high ground: 50 feet or more above sea level

  
• Soil erosion

  A gradual process that occurs when the impact of water or wind detaches and removes soil particles, causing the soil to deteriorate
• Landslide


  A movement of earth, rock, or debris due to gravity, can be caused by continuous heavy rainfall, strong earthquakes, or human activities
• Common Types of Landslide

  • Rotational slides
  • Translational slides
  • Rock fall
  • Rock toppling
  • Lateral spreading
  • Debris flow
  • Earthflow
  • Creep
• Rotational slides


  • Move along a surface of rupture that is curved and concave

  
• Translational slides


  • Occur when the failure surface is approximately flat or slightly undulated

  
• Rock fall

  • Free falling detached bodies of bedrock (boulders) from a cliff or steep slope

  
• Rock toppling


  • Occurs when one or more rock units rotate about their base and collapse

  
• Lateral spreading


  • Occurs when the soil mass spreads laterally and this spreading comes with tensional cracks in the soil mass

  
• Debris flow


  • Down slope movement of collapsed, unconsolidated material typically along a stream channel

  
• Earthflow


  • Exhibit an hourglass shape, with slope material liquefying and flowing downhill, forming a depression at the top