Summative

• Volcano


  Comes from the Latin word "volcanus"
• Volcano


  • Openings
  • Rupture
  • Vent
  • Earth's geologic architects
• Plate tectonics


  Made when two tectonic plates come together
• Parts of a volcano

  • Summit
  • Slope
  • Base
  • Crater
  • Caldera
• Volcanic hazard


  Observable facts arising due to volcanic activity such as eruption, with potential threat and direct impact on humans, animals, properties, infrastructure, tourism, and political stability
• Types of volcanoes


  • Cinder cone volcano
  • Composite cone volcano
  • Shield volcano
• Volcanic eruption


  • Leads to different hazards such as Ballistic projectiles, Ash fall, Pyroclastic flows, Lava flows, Volcanic gases, Debris Avalanche or Volcanic landslide, and Tsunami
• Cinder cone volcano


  • Simplest and most common type
  • Built from ejected lava fragments
  • Steep slope, wide crater
  • Most abundant of the three major volcano types
• Ballistic projectiles


  Rock fragments ejected from volcano's mouth, comparable to cannonballs, reaching up to 5 km or 3 mi
• Cinder cone volcanoes


  • Paricutin Volcano of Mexico
  • Mauna Kea of Hawaii
• Ash fall or tephra fall


  Minute volcanic particles such as pulverized rock, minerals and silicon, formed during explosive volcanic eruption
• Composite cone volcano


  • Tall, symmetrically shaped, with steep sides
  • Large, nearly perfect sloped structure
  • Formed and built up by many layers of alternating solidification of lava and pyroclastic deposits
• Pyroclastic flows


  Highly-density mix of hot lava blocks, pumice, ash and volcanic gases, moving at very high speed down volcanic slopes
• Composite cone volcanoes


  • Mount Fuji of Japan
  • Mt. Mayon Volcano of Philippines
• Lava flows


  Streams of molten rocks poured or oozed from an erupting vent
• Shield volcano


  • Broad volcano with sloping sides
  • Formed mainly out of runny lava
  • Formed by the accumulation of lava that oozes out from the volcano
  • Broad, slightly domed structure that resembles a warrior's shield
• Volcanic gases


  Gases dissolved in magma that provide the driving force for volcanic eruptions, released into the atmosphere as pressure decreases
• Shield volcanoes


  • Mauna Loa of Hawaii
  • Erta Ale of Ethiopia
• Debris avalanche or volcanic landslide

  Massive collapse of a volcano, usually triggered by an earthquake or volcanic eruption
• Classifications of volcanoes


  • Active
  • Inactive
• Tsunami


  Sea waves or wave trains generated by sudden displacement of water, such as during undersea eruptions or debris avalanches
• Lahar


  Mixtures of volcanic water and rock fragments that rush down volcano slopes and into surrounding valleys, often triggered by heavy rains or earthquakes
• Active volcano


  • Has a record of eruption within the last 600 years or erupted 10,000 years ago
  • Volcano which is either erupting or is likely to erupt in the future
• Active volcanoes


  • Kilauea
  • Mauna Loa
  • Mauna Kea
• Lightning strikes


  Occur during volcanic eruptions due to friction between ash, rock fragments, steam and gases in the eruption cloud
• Inactive volcano


  • Otherwise known as "dormant" volcanoes
  • Have not erupted for the last 10,000 years
  • Physical form is being changed by weathering and erosion
  • Expected to erupt again in the future
• Potential volcanic hazards are harmful because they directly affect humans, animals, properties, infrastructure, tourism, and political stability
• Inactive volcanoes


  • Mount Fuji of Japan
  • Mount Kilimanjaro of Tanzania, Africa
• Volcanic hazards threaten human health through impacts, respiratory issues, contamination, and destruction
• Factors affecting volcano eruption

  • Magma's temperature
  • Magma's chemical composition
  • Amount of dissolved gases in magma
• Viscosity


  • Property of a material's resistance to flow
  • Described as the liquid's thickness and stickiness
  • The more viscous and thicker the material, the greater its resistance to flow
• Temperature of magma


  Viscosity decreases as temperature increases
• Composition of magma


  • Magmas with high silica content are more viscous than those with low silica content
  • Magma with less silica content is relatively fluid and travels far before solidifying
  • Lava with less silica content can travel a great distance and forms a thin sheet of lava
• Composition of magma


  • Lava with low amount of gas and high silica content is very viscous and does not flow out as it rises, forming a columnar plug in the vent
  • Lava with low amount of gas as it rises has high viscosity that it piles up at a vent resulting in a dome
• Types of volcanic eruption

  • Magmatic eruption
  • Phreatomagmatic eruption
  • Phreatic eruption
• Magmatic eruption


  • Produces juvenile clasts during explosive decompression from gas release
  • Includes the ejection of lava or tephra from a magma source within the earth
  • Generally described as being effusive or explosive
• Phreatomagmatic eruption


  • Violent eruption due to the contact between water and magma
  • Results in a large column of very fine ash and high-speed and sideways emission of pyroclastics called base surges
  • Driven by the thermal contraction of magma when it comes in contact with water
• Phreatic eruption


  • Stream-driven eruption as hot rocks come in contact with water
  • Short lived, characterized by ash columns but may be an onset of a larger eruption
  • Driven by the expansion of steam
• The Philippines ranks second in the world's production of geothermal energy
• 14.4% of the Philippines' total power generation is produced from geothermal energy