Volcanic Eruptions

• What is the main objective of studying volcanic eruptions?

  Explain the process of a volcanic eruption
• How are volcanoes formed on land?

  When one tectonic plate subducts another
• What happens to the oceanic plate during subduction?

  It sinks into the mantle
• What does volcanic process refer to?

  Eruptive and non-eruptive activities in a volcano
• What can cause a volcanic eruption?

  Decrease in confining pressure or increase in vapor pressure
• What determines the viscosity of lava?

  Silica content, temperature, and dissolved gases
• What happens to magma as it rises?

  It collects in magma chambers and pushes through vents
• What are the two types of volcanic eruptions based on activity?

  Explosive and effusive eruptions
• What characterizes explosive eruptions?

  Gas-driven explosions that propel magma and tephra
• What is a magmatic eruption?

  Ejection of lava or tephra from a magma source
• What is a phreatic eruption?

  An eruption driven by magma interacting with water
• What distinguishes a phreatomagmatic eruption?

  Interaction of new magma with water, often explosive
• What characterizes Hawaiian eruptions?

  Effusive emission of highly fluid basalt lava
• What causes Strombolian eruptions?

  Bursts of gas bubbles within the magma
• What happens during a Vulcanian eruption?

  Pressure of gases blows off the crust of lava
• What occurs during a Pelean eruption?

  Gas, dust, ash, and lava fragments are expelled
• What is a Plinian eruption known for?

  Being the most explosive and powerful eruption
• What characterizes a Surtseyan eruption?

  Magma interacts explosively with shallow water
• Where do submarine eruptions occur?

  Beneath the surface of the water
• What is glaciovolcanism?

  Interaction between lava and ice under glaciers
• What is the role of PHIVOLCS?

  Mitigate disasters from geotectonic phenomena
• What are steam-blast eruptions also called?

  Phreatic eruptions
• What signs indicate a volcano may erupt?

  Increase in volcanic quakes and steaming activities
• What happens to vegetation around a volcano before an eruption?

  It dries up noticeably
• What should be prioritized before a volcanic eruption?

  Safety of children and elderly
• What are the steps to prepare for a volcanic eruption?

  Before:

  • Prioritize safety of children and elderly
  • Prepare necessary supplies (food, water, etc.)

  During:

  • Seek shelter indoors and cover
  • Wear a mask when cleaning ash

  After:

  • Check the entire house for damage
• What are the classifications of volcanic eruptions?

  • Magmatic eruptions
  • Phreatomagmatic eruptions
  • Phreatic eruptions
• What factors influence the characteristics of volcanic eruptions?

  • Viscosity of the magma
  • Silica content
  • Temperature of the lava
  • Dissolved gases in magma
• What are the signs that a volcano is about to erupt?

  • Increase in volcanic quakes
  • Change in steam color from white to gray
  • Crater glow due to magma presence
  • Ground swelling and fissures
• What are the effects of submarine eruptions?

  • Risk of tsunamis
  • Health impacts from ash ejection
• What are the effects of phreatic eruptions?

  • Driven by steam expansion
  • Can produce ash but no new magma
• What is the significance of monitoring volcanic activity?

  • Helps predict eruptions
  • Ensures public safety
  • Mitigates disaster impacts