DRRR

• Volcano


  A mountain or hill, typically conical, having a crater or vent through which lava, rock fragments, hot vapor, and gas are being or have been erupted from the earth's crust
• Parts of a Volcano

  • Magma
  • Parasitic Cone
  • Sill
  • Vent
  • Flank
  • Lava
  • Crater
  • Conduit
  • Summit
  • Throat
  • Ash
  • Ash Cloud
• Magma


  Molten rock beneath Earth's surface
• Parasitic Cone


  A small cone-shaped volcano formed by an accumulation of volcanic debris
• Sill


  A flat piece of rock formed when magma hardens in a crack in a volcano
• Vent


  An opening in Earth's surface through which volcanic materials escape
• Flank


  The side of a volcano
• Lava


  Molten rock that erupts from a volcano that solidifies as it cools
• Crater


  Mouth of a volcano - surrounds a volcanic vent
• Conduit


  The pipe or vent at the heart of a volcano where material wells up from beneath the surface
• Summit


  Highest point; apex
• Throat


  Entrance of a volcano. The part of the conduit that ejects lava and volcanic ash
• Ash


  Fragments of lava or rock smaller than 2 mm in size that are blasted into the air by volcanic explosions
• Ash Cloud


  A cloud of ash formed by volcanic explosions
• 1.      Composite Volcano - Composite volcanoes, or stratovolcanoes make up some of the world’s most memorable mountains: Mount Rainier, Mount Fuji, and Mount Cotopaxi, for example. 2.      Shield Volcanoes - These are large, broad volcanoes that look like shields from above – hence the name.
• 3.      Cinder Cones - These small conical hills form when hot gas and ash erupted from fissures on the ground cool rapidly as they fall back to Earth.
• Active volcanoes


  Have a recent history of eruptions; they are likely to erupt again
• Dormant volcanoes


  Have not erupted for a very long time but may erupt at a future time
• Extinct volcanoes


  A volcano that no one expects will ever have another eruption
• One such extinct volcano is located on Hawaii's Big Island and its name is Kohala. The last time that Kohala erupted was close to 60,000 years ago.
• Lava Flows


  Streams of molten rock that pour or ooze from an erupting vent
• Pyroclastic Flows


  Contain a high-density mix of hot lava blocks, pumice, ash and volcanic gas. They move at very high speed down volcanic slopes typically following valleys.
• Lahars


  A specific kind of mudflow made up of volcanic debris
• Ash Fall


  Volcanic ash consists of fragments of pulverized rock, minerals and volcanic glass, created during volcanic eruptions and measuring less than 2 mm in diameter. The term volcanic ash is also often loosely used to refer to all explosive eruption products (referred to as tephra), including particles larger than 2 mm.
• Volcanic Gases


  Magma contains dissolved gases, which provide the driving force that causes most volcanic eruptions. As magma rises towards the surface and pressure decreases, gases are released from the liquid portion of the magma and continue to travel upward and are eventually released into the atmosphere. Lage eruptions can release enormous amounts of gas in a short time.
• Ballistic Projectiles


  Rocks that an erupting volcano may hurl into the air. These blocks and bombs travel like cannonballs and usually land within 2 kms of the vent.