DRRR

• Volcanic eruption


  An eruption of molten rock, hot rock fragments, and hot gases through a volcano, which is a vent in a planet's or satellite's crust

  
• Volcano


  • A mountain or a hill formed by the eruptions of accumulated materials from one or more openings, called volcanic vents, in the earth's surface
  • Most volcanoes have steep sides, but some can be gently sloping mountains even flat tablelands, plateaus, or plains
  • The volcanoes above sea level are the most popular, but the majority of the world's volcanoes lie beneath the sea

  
• Pacific Ring of Fire


  • A horseshoe-shaped region encircling the Pacific Ocean characterized by intense volcanic and seismic activity
  • Home to approximately 75% of the world's active and dormant volcanoes, making it one of the most volcanically active areas on Earth
  • The Ring of Fire's volcanic activity is a result of the Pacific Plate subducting beneath several other tectonic plates, creating immense pressure and heat that leads to the formation of magma and volcanic eruptions

  
• Volcanic eruption process


  1. Magma accumulates in the magma chamber beneath the Earth's surface due to heat and pressure

  2. Magma passes into a pipelike conduit

  3. Rising magma causes gas expansion, increasing pressure inside the volcano

  4. Lava releases at the vent of the volcano

  5. When pressure becomes too great, the volcano erupts, expelling magma, gas, and ash
• Active volcano


  A volcano which is either erupting or is likely to erupt in the future
• Dormant volcano


  An active volcano which is not currently erupting but is expected to erupt again in the future
• Extinct volcano


  Volcanoes which scientists consider unlikely to erupt again, as they no longer have a lava supply and are no longer near an active geologic hot spot
• Types of volcanoes


  • Active
  • Dormant
  • Extinct
• Volcanic eruption materials


  • Mixtures of hot rock fragments, and gas
  • Deadly due to high temperatures of 850°C or higher and fast speeds of 250 km/h or greater

  
• Lava flows


  • Move much more slowly than pyroclastic flows, rarely life threatening but can produce massive property damage and economic loss
• Volcanic ash


  • Heavy accumulations, especially if they become wet from rainfall, can collapse roofs and damage crops
• Volcanic gases


  • Carbon dioxide and sulfur dioxide are poisonous gases that may affect the residents in the area
• Lahars


  • Composed of wet concrete-like mixtures of volcanic debris and water, can travel quickly through valleys, destroying everything in their paths
• Undersea volcanic eruptions


  • Can trigger tsunamis that may affect those who are near the shorelines
• Explosive volcanic eruptions


  • Eject volcanic ash into the atmosphere, posing a serious hazard to airplanes
• Volcanic eruption effects


  • Cracks in the earth's surface through which magma may pour out
• Volcanic eruption hazards


  • Pyroclastic flows
  • Lava flows
  • Volcanic ash
  • Volcanic gases
  • Lahars
  • Tsunamis
  • Ash clouds
  • Cracks in the earth's surface

  
• Precautionary measures before a volcanic eruption

  1. Prepare emergency kit

  2. Choose appropriate face masks

  3. Monitor local news and updates

  4. Know emergency hotlines

  
• Precautionary measures during a volcanic eruption

  1. Stay indoors

  2. Avoid driving

  3. Use protective gear if going outside

  4. Continue listening to updates
• Precautionary measures after a volcanic eruption

  1. Assess and mitigate damage

  2. Clear roofs of ash fall
• Emergency hotlines


  • 911
  • 117 (Philippine National Police)
  • 8929-8958, 8426-1469-79 (PHIVOLCS)
  • 143 (Philippine National Red Cross)
  • 117, 3410-6319 (Bureau of Fire Protection)
  • 8911-1406, 8911-2665, 8911-5061 to 65 (National Disaster Risk Reduction & Management Council)
  • [phone], 8711-1001 to 02 (Department of Health)
  • 8927-1541, 8926-4251 (PAGASA)
  • 8511-1259 (Department of Social Welfare and Development)
• The Philippines is located at the Pacific Ring of Fire, making it prone to earthquakes.
• Geologic hazards


  Geologic conditions that may pose a hazard to lives and properties when exposed to heavy or prolonged rain
• Landslide


  • Ground movement on a sloping terrain
  • Does not happen on flat grounds
  • Gravity induces the land to move downward

  
• Rain


  Can induce or aggravate the hazard of landslides
• Water is a natural agent for erosion, and if rain or any source of water frequently flows down a sloping area, the gravitational descent of loosened soil makes it possible for landslides to occur

  
• Landslide


  • Landslide in Tublay, Benguet
• Landslides


  • Can have devastating impacts, including loss of life, property damage, infrastructure disruption, economic setbacks, and ecological changes
  • Can displace communities, alter natural landscapes, and lead to siltation and water quality issues
  • The economic burden of landslide-related costs, coupled with potential secondary hazards and increased vulnerability to future landslides, underscores the importance of effective risk management, mitigation measures, and public awareness to minimize the consequences of these geologic events

  
• Sinkhole


  Depressions or holes on the ground that resulted from the collapsed of the surface layer of the soil
• Sinkholes


  • Occur in areas where the soil foundation is made of soft minerals and rocks such as silicate materials, salt beds, or any acidic rocks
  • These rocks can be further weakened by frequent submersion in water
  • Unmanaged rocks dissolve in water and gradually weaken, carving and forming spaces and underground passages for water
• Hydrometeorological Hazards


  Dangers associated with the natural processes involved in the transfer of water and energy between the land and surface
• The Philippines is in the Northern Hemisphere, above the Equator. The area near the equator is known as the Intertropical Convergence Zone (ITCZ). This is where trade winds meet.

  
• Trade winds flow in opposite directions, mainly the reason for strong swirling winds. These winds can intensify different hazards associated in this course.
• Typhoon


  Intense circulating winds with heavy rain over tropical waters and land
• Typhoons are actually tropical cyclones whose winds reached over 118 kph, which is why it is described as "intense"
• PAGASA


  Monitors typhoons and they establish five public storm warning signals (PSWS) which determines the wind intensity
• Thunderstorms


  Also known as electrical storm, characterized by heavy rain with thunder and lightning
• Thunderstorms happen due to an uneven distribution of heat and air on land. Thunderstorms usually occur during summer.
• Hazards associating thunderstorms


  • Heavy rainfall
  • Lightning
  • Air turbulence
  • Fire
• Flood


  The presence of excessive water on a supposedly dry land, can be caused by continuous heavy rain or poor drainage