DRRR MST 4Q

• Volcano


  An opening or vent on the earth's surface where molten rocks, gases, and ashes are ejected
• Different Types of Volcanoes

  • Cinder Cone Volcano
  • Shield Cone Volcano
  • Composite Volcanoes (Strata Volcanoes)
• Cinder Cone Volcano


  • Simplest type formed from lava particles emitted in a vent
  • Example: Paricutin in Mexico
• Shield Cone Volcano


  • Created by continuous lava flows from the vent
  • Examples: Kilauea and Mauna Kea in Hawaii
• Composite Volcanoes (Strata Volcanoes)


  • Often steep-sided and symmetrical in shape
  • Examples: Mayon, Mt. Shasta
• Classification of Volcanoes


  • Active Volcano
  • Dormant Volcano
  • Extinct Volcano
• Active Volcano


  Erupted within the last 10,000 years, further classified as erupting or dormant
• Dormant Volcano


  Hasn't erupted in the last 10,000 years but expected to in the future
• Extinct Volcano


  Not erupted in historic times and not expected to erupt again
• Signs of an Impending Eruption

  • Volcanic earthquake
  • Increase in steam emission
  • Rumbling sounds
  • Drying up of vegetation
  • Unusual change in water level at a crater lake
  • Unusual behavior of animals
• Various Volcano-related Hazards


  • Lava Flow
  • Volcanic Gases
  • Pyroclastic Flows
  • Tephras
  • Lahar
• Lava Flow


  • Fluid or viscous depending on composition
  • Types: Pahoehoe (fluid), Aa (viscous)
  • Negative impacts: Crushing structures, burning surroundings
• Volcanic Gases


  • Composed of different materials, including water vapor, carbon dioxide, sulfur dioxide
  • Negative impacts: Irritation, acid rain, asphyxiation
  • Mitigation: Monitoring, public awareness
• Pyroclastic Flows


  • Hot, turbulent mixtures of materials and gases moving downhill
  • Types: Soufriere, Pelee, Merapi
  • Highly destructive, early warning and evacuation essential
• Tephras


  • Ejected volcanic material categorized by size
  • Negative impacts: Spread over wide areas, hinder aircraft, burial
  • Ballistic projectiles: Proximity effects
• Lahar


  • Slurry formed by mixing tephras with water
  • Types: Primary and Secondary
  • Negative impacts: Destruction, quick movement
  • Mitigation: Hazard avoidance, warning, response planning
• Volcanic Explosivity Index (VEI)


  Relative measure of eruption explosiveness
• Hydrometeorology


  • Studies the transfer of water and energy between the land surface and the lower atmosphere
  • Deals with problems involving the hydrologic cycle, water budget, and rainfall statistics
• Hydrometeorological Hazards


  • Caused by extreme meteorological and climate events such as floods, droughts, hurricanes, tornadoes, or landslides
  • Account for a dominant fraction of natural hazards globally
• Tropical Cyclones


  • Intense circular storms originating over warm tropical oceans
  • Also called hurricanes or typhoons
  • Classified by PAGASA into five categories based on sustained winds
• Precautionary Measures for a Typhoon

  • Stay updated on forecasts
  • Stay indoors, secure windows and doors
  • Bring in belongings
  • Seek higher ground if in coastal areas
  • Do not go out until declared safe
• Thunderstorms


  • Characterized by heavy rain, wind, lightning, and thunder
  • Formation involves convection, updrafts, and downdrafts
  • Types include single cell, multi-cell, supercell, and squall line
• Precautionary Measures Before and During a Thunderstorm


  • Stay indoors, secure openings
  • Seek shelter, unplug electrical appliances
  • Avoid water contact
  • If on water, get to land
  • If in an open field, avoid trees/high points
• Flooding


  • Involves temporary rise or overflowing of water bodies
  • Causes include heavy rains, overflowing rivers, broken dams, clogged drainage systems
• Tsunamis


  Waves generated by seismic activity, often subduction
• Storm Surge


  • Abnormal rise in seawater level during a storm
  • Influenced by factors like topography and typhoon track
  • PAGASA issues color-coded storm surge warnings
• El Niño and La Niña

  • Part of the El Niño-Southern Oscillation (ENSO) cycle
  • El Niño causes drought, while La Niña causes above-normal rainfall in the Philippines
  • Impact agriculture, food supply, and fresh water availability
• Monsoon


  • Seasonal, regional weather systems producing heavy rains
  • Southwest monsoon (Habagat) occurs between June to August/September
  • Northeast monsoon (Amihan) occurs between December to February
• Intertropical Convergence Zone (ITCZ)


  • Area near the Equator where northeast and southeast winds converge
  • Also known as the doldrums or calms
• Monitoring Tools


  • PAGASA utilizes aerial photographs, satellite images, and the NOAH website for monitoring hydrometeorological hazards
• Volcanic hazard


  Any potentially dangerous volcanic process (e.g. lava flows, pyroclastic flows, ash)
• Volcano


  An opening or vent on the earth's surface where molten rocks, gases, and ashes are ejected
• Different types of volcano

  • Cinder cone
  • Shield cone
  • Composite volcanoes
• Cinder cone volcanoes


  • Particutin (Mexico)
  • Taal (Philippines)
• Shield cone volcanoes


  • Kilauea
  • Mauna Kea (Hawaii)
  • House Mountain-Arizona
• Composite volcanoes


  • Mayon
  • Mt Shasta
• Classification of volcanoes


  • Active volcanoes
  • Dormant volcanoes
  • Extinct volcanoes
• Active volcano


  Has at least one eruption within the last 10,000 years
• Erupting volcano


  An active volcano that erupts, distinguished as either explosive or quiet
• Dormant volcano


  Has not erupted within the last 10,000 years, but is expected to occur in the future