Science

• A volcano is a mountain or hill, typically conical, having a crater or vent through which lava, rock fragments, hot vapor, and gases are being or have been erupted from the Earth's crust
• The term volcano comes from the name of the Roman god of fire, Vulcan
• A volcano is a ‘chimney’ that connects magma from within the Earth's crust to the Earth's surface
• Magma is hot, molten rock forced up the central vent and eventually through the crater
• Lava is hot, molten rock on the Earth's surface
• Sill: horizontal crack within a volcano holding hardened magma
• Conduit, also known as the central vent, is the path from the magma chamber to the crater
• Active volcanoes are those that have erupted within the last 600 years
• Top 5 most active volcanoes based on number of eruptions: Makaturing, Bulusan, Kanlaon, Taal, Mayon
• Inactive volcanoes have not erupted for the last 10,000 years
• Extinct volcanoes are not known to have erupted within modern history and have been worn away almost to the level of their magma chamber
• Pyroclastic flows are mixtures of hot gas, ash, and other volcanic rocks travelling quickly down the slopes of volcanoes, one of the most dangerous hazards posed by volcanoes
• Lahars are mudflows formed by mixing volcanic particles and water
• Volcanic ash is a volcanic rock exploded from a vent in fragments less than 2mm in size
• Volcanic gas is contained within magma and released as the magma rises to the Earth's surface
• Viscosity is a measure of a fluid's resistance to flow, with less silica content leading to low viscosity where low viscosity flows easily
• Types of lava include:

  • Pahoehoe Lava: ropelike surface texture, relatively hot, low viscosity lava
  • Aa Lava: blocky, rough lava flow due to high viscosity
  • Pillow Lava: forms when lava flows into water, creating a closed lava tube with a bulbous end
• Types of eruption:

  • Phreatic: hot rocks come in contact with water
  • Phreatomagmatic: contact between water and magma
  • Strombolian: characterized by fountain lava
  • Vulcanian: tall eruption columns
  • Plinian: excessively explosive type of eruption
• Crater is the cup-shaped top part of a volcano
• Vent is an opening in the volcano where lava comes out
• Summit is the highest point of a volcano
• Base is the lowest part, bottom or supporting layer of a volcano
• Slope is the angle made by the lower flank of the volcano and the peak
• Magma Chamber is a place in the mantle that stores magma
• Side Vent is a vent on the side of a volcano for escaping steam, gas, and lava
• Volcano


  An opening in a planet's crust that allows hot gases, magma, and ash to evolve from underneath Earth's surface
• Mayon Volcano is the most active volcano in the Philippines
• Magma emission of a volcano

  Depends on its shape
• Volcano eruption


  Heat and pressure cause rocks to melt, form magma, goes up of the chamber, and develop gas bubbles as it rises
• Ingredients that affect the type of explosion and shape of a volcano

  • Silica and dissolved gas
• Volcanic ash may cause a decrease in the earth's average temperature for a few years
• As the temperature of magma increases

  Its viscosity decreases
• Viscosity


  The property of materials' resistance to flow
• The higher the temperature of the magma, the lower its viscosity
• Pacific Ring of Fire


  A tectonic belt that surrounds the Pacific Ocean and is characterized by
• Geothermal energy


  Heat derived within or coming from inside the earth that generates electricity
• Of the country's total electricity production, 26% is generated from power plants
• Classification of Volcano


  • Active volcanoes
  • Inactive volcanoes (dormant)
  • Extinct volcanoes
• Active volcanoes


  • Have a record of eruption within the last 600 years or those that erupted 10,000 years ago based on analyses of their materials
• Inactive (dormant) volcanoes


  • Have not yet erupted recently, but may do so again