Science

• Volcanoes are natural opening in the earth's surface where molten rocks, smoke, gases and ashes are ejected
• Parts of the volcano are:

  1. Summit
  2. Slope
  3. Base
• Crater is a funnel shape depression at the top of a volcano formed as a result of explosive eruption
• Taal volcano has 47 craters
• Caldera is a volcanic crater that is formed when a part of the wall of the crater collapses following an explosive eruption
• Magma is a molten rocks inside the earth
• Lava is a magma that has been ejected out of the volcano
• Types of volcano according to shape:

  1. Shield volcano
  2. Cinder cone volcano
  3. Composite volcano
• Shield volcano is formed by the accumulation of lava oozes out from the volcano.
• Since non-viscous lava can flow freely
• Shield volcano is a broad, slightly doomed structure that resembles a warrior shield is formed
• Example of shield volcano is mauna loa in hawaii
• Cinder cone volcano is built from ejected lava fragments
• Cinder cone volcano has a steep slope, wide crater and is most abundant of the three major volcanoes
• Example of cinder cone volcano is paricutin in mexico
• Composite volcano also known as stratovolcano is a large nearly perfect slope structure formed from the alternate solidification of both lava and pyroclastic deposits
• Example of composite volcano is mayon in philippines
• Types of volcanoes due to its eruption:

  1. Phreatic/hydrothermal
  2. Phreatomagmatic
  3. Strombolian
  4. Vulcanian
  5. Plinian
• Phreatic or hydrothermal is a stream driven eruption as the hot rocks come in contact with water
• Phreatomagmatic is a violent eruption due to the contact between water and magma
• Strombolian is a period weak to violet eruption characterized by fountain lava
• Vulcanian is characterized by tall eruption that reach up to 20 km high with pyroclastic flow and ashfall tepra
• Plinian is excessively explosive type of eruption of gas and pyroclastics
• Types of volcano according to its record of eruption:

  1. Active volcano
  2. Inactive volcano
• Parasitic cone is a small cone shaped volcano formed by an accumulation of volcanic debris
• Sill is a flat piece of rock formed when magma hardens in a crack in a volcano
• Vent is an opening in earth's surface through which volcano materials escape
• Flank is the side of the volcano
• Conduit is an underground passage that magma travels through
• Summit is the highest point or apex
• Throat is the entrance of a volcano also the part of the conduit that ejects lava and volcanic ash
• Ash is a fragments of lava or rock smaller than 2 mm in size that are blasted into the air by volcanic explosion
• Ash cloud is a cloud of ash formed by volcanic explosion
• active volcano is a volcano that has had at least one record of eruption during the past 10,000 years
• Dormant volcano is an active volcano that is not erupting but supposed to erupt again
• There are 24 active volcanoes in the earth

  1. Iraya
  2. Smith
  3. Babuyan claro
  4. Didicas
  5. Cagua
  6. Camiguin de babuyanes
  7. Pinatubo
  8. Biliran (anas)
  9. Banahaw
  10. Taal
  11. Isarog
  12. Iriga
  13. Mayon
  14. Bulusan
  15. Kanlaon
  16. Cabalian
  17. Hibok-hibok
  18. Musuan (calayo)