volcanic eruption

• The Philippines is situated in the Pacific Ring of Fire, characterized by frequent earthquakes and volcanic eruptions
• Volcanism is a phenomenon connected with volcanoes and their volcanic activity
• Volcanoes are formed as a result of geological activities along plate boundaries in the Ring of Fire
• Types of Volcanoes:

  • Cinder cone volcano (or Scoria cone volcano): Forms when volcanic cinder or blobs of congealed lava of basaltic composition come out from one vent
  • Composite volcano (or Stratovolcano): Composed of alternating layers of lava flow, with extremely explosive and dangerous eruptions
  • Shield volcano: Huge gently sloped volcanoes that exclusively erupt basaltic lava
  • Lava dome (or Volcanic dome): Relatively small circular mounds formed because the lava is too viscous to flow
• Classification of Philippine Volcanoes:

  • Active erupting: volcano having an eruption
  • Active dormant: not erupting but supposed to erupt again
  • Inactive: one that could erupt but has not erupted for more than ten thousand years
• The Philippines has more than 100 volcanoes as of 2013

  • 24 active volcanoes are located in the country, with the majority in Luzon Island
• Characteristics of Inactive Volcanoes:

  • Inactive volcanoes are also known as extinct or sleeping
  • Expected to erupt again despite being dormant for thousands of years
  • Volcanoes with no record of eruptions are considered extinct or inactive
  • Physical form altered by weathering and erosion
• Advantages and Disadvantages of Living Near Volcanoes:

  • Risk of destruction to land by volcanic materials, landslides, pollution, and effects on weather
  • Volcanic materials are important for human life, containing nutrients that enrich the soil and useful in industrial and chemical uses
  • Attracts tourists and provides a source of living for people in nearby areas
• Volcanism and Volcanic Activity:

  • Volcanism is connected with volcanoes and their activity, involving the movement of magma from the mantle to the surface
  • A volcano is a mountain that opens downward to a pool of molten rock below the surface
  • Hot liquid rock under the earth's surface is known as magma, and once it erupts through the earth's surface, it is called lava
  • Volcanoes may form from melted crust, subduction, underwater, or hot spots
  • Four types of volcanoes according to shape: cinder cone, composite, shield, and lava dome
• • Volcanoes classified as active erupting, active dormant, or inactive by PHIVOLCS (Philippine Institute of Volcanology and Seismology)