VOLCANOES

• These are natural opening in the Earth‘s surface where molten rocks (magma), smoke, gases, ashes are ejected.
• Mayon volcano is located in Albay, Philippines.
• Tiny little island of Vulcan point in the Philippines is the world’s largest Island within a lake.
• Vulcan Point happens to be one of the cones of the active Taal volcano
• Volcanism is a phenomenon connected with volcanoes and its volcanic activity.
• A volcano is a mountain that opens downward to a pool of molten rock below the surface of the earth.
• Three basic parts of a volcano: Base, Slope, and Summit.
• Crater is a funnel shaped depression at the top of the volcano formed as a result of a explosive eruption.
• Taal volcano is located in Batangas, Philippines. And has a total of 47 craters.
• Laccolith is a body of intrusive rock with a dome-shaped upper surface and a level base, fed by a conduit from below.
• Laccolith forms when magma (molten rocks) rising through the Earth‘s crust begins to spread out horizontally, prying apart the host rock strata.
• Ash is fragments of lava or rocks smaller then 2mm in size that are blasted into air by volcanic explosions.
• Ash cloud is clouds formed by volcanic explosions.
• Caldera is a volcanic crater that is formed when a part of the wall of the crater collapses following an explosive eruption.
• Magma - molten rock beneath the Earth’s surface.
• Magma chamber is a large underground pool of molten rock sitting underneath the earth‘s crust.
• lava is the italian word which means to slide.
• Parasitic cone - small cone-shaped volcano formed by accumalation of Volcanic debris.
• Sill - flat piece of rock formed when magma hardens in a crack in a volcano.
• Vent - an opening in the Earth’s surface trough which volcanic material escapes.
• In the ring of fire, volcanoes are formed in the subduction zone.
• Underwater volcanoes - formed along the rift of two plates which are being pulled apart. Magma rises out of the riff from the sea floor spreads.
• Hot stop volcanoes - formed at the center of the plate by plumes. It is a rising column of superhot magma from some places in the mantle.
• Volcanoes can be classified according to its shape and according to its eruption.
• Shield volcano

  • Huge, gently sloped volcanoes that exclusive erupts basaltic lava.
  • Include a number of the biggest volcanoes within the world.
  • Built by many layers of low-viscous lava flows. The eruptions don’t seem to be explosive.
  • As high as 9000 meters from the bottom.
  • This is formed by the accumulation of lava oozes out from the volcano.
  • A broad slightly doomed structure that resembles warrior’s shield is formed.
• Cinder cone volcano

  • also known as SCORIA CONE
  • forms when volcanic cinder or blobs of congealed lava of basaltic composition, comes out from one vent.
  • Its explosive eruptions are caused by gas rapidly expanding and escaping from the molten lava that comes out, sort of like a fountain.
  • The lava cools quickly, and falls a cinder spilled up around the vent form a round shape living a crater at a summit.
  • As high as 100 to 400 meters.

  This is built from ejected lava fragments. They have a steep slope, wide crater, and is most abundant of the three volcanoes.
• Composite volcano (stratovolcano)


  A large, nearly perfect sloped structure formed from the alternate solidification of both lava and pyroclastics
• Composite volcano


  • Composed of alternating layers of lava flow
  • Up to 100 to 3500 meters high
  • Can have a cluster of vents
  • Eruptions are extremely explosive and dangerous
• According to volcanologists, some of the Earth’s grandest mountains are composite or stratovolcanoes
• Pressure builds within the magma chamber


  Gases under immense heat and pressure are dissolved within the magma
• Lava dome volcano

  • also referred to as Volcanic Dome.
  • Small, circular mounts formed because the lava is simply too viscous to flow. Height depends on the dimensiions of the composite volcanoes around them.
• phreatic

  • It is a stream given eruption as rocks come in contact with water.
  • Also known as hydrothermal.
• phreatomagmatic

  • contact between water and magma.
  • happens if there is an interaction between water and magma resulting to violent fine ash eruption.
• Strombolian

  • it is a period weak to violent eruption characterized by fountain lava.
• Vulcanian

  • it is characterized by tall eruption that reach up to 20km high with pyroclastic flow and ashfall tephra.
• Plinian

  • exessively explosive.