DRRR

• Volcano - is a vent, or mountain from which magma (molten or hot rocks with gaseous materials) are ejected onto the earth’s surface.
• Volcanic eruption – is the process wherein these volcanic materials are ejected from a volcano.
• WARNING SIGNS OF IMPENDING VOLCANIC ERUPTION

  • Swelling, cracking or sinking of the ground

  • Swarms of earthquakes

  • Noticeable steaming or fumarolic activity

  • Plume

  • Gases
• EQUIPMENTS/INTRUMENTS USED TO MONITOR OR MEASURE…

  • GROUND DEFORMATION

  • Electronic Distance Meter (EDM)

  • Use of Remote sensing images also help compare before and after features.

   

  • SEISMIC ACTIVITY

  • Seismometer
• Electronic Distance Meter (EDM) - to measure accurately to millimeter changes on ground (if the slope for the volcano swells
• • Global Positioning System (GPS) – Deformation on ground is also measured using data of repeated measurements from permanent
• Seismometer is the equipment used to detect occurrence of volcanic earthquakes
• PARAMETERS USED IN MONITRING VOLCANIC ERUPTION

  ▪ GROUND DEFORMATION

  ▪ GEOCHEMISTRY

  ▪ SEISMIC ACTIVITY

  ▪ AUDITORY OBSERVATION

  ▪ VISUAL OBSERVATION

  ▪ OLFACTORY

  ▪ FEEL

   
• GROUND DEFORMATION - Refers to surface changes on a volcano, such as subsidence (sinking), tilting, or bulge formation, due to the movement of magma below the surface.
• GEOCHEMISTRY - Rise through vents called fumaroles (from the Latin for “smoke”) and other cracks. Sometimes the concentrations are high enough to create acid rain that kills vegetation.

   
• SEISMIC ACTIVITY - From earthquakes to swarms of earthquakes. Most unrest in volcanoes start with volcanic earthquakes. Volcanoes and earthquakes go hand in hand. The challenge is to determine which patterns of seismic waves precede an eruption.
• VOLCANIC HAZARD MAP - visual, geospatial depictions of the areas that could be impacted by various volcanic phenomena during or subsequent to an eruption.
• VOLCANIC HAZARDS – are phenomena arising from volcanic activity that pose potential threat to a person or property in a given area.

   
• VOLCANIC HAZARDS

  1. Lava Flow

  2. Ashfall or tephra fall

  3. Pyroclastic flows and surges

  4. Lahar

  5. Volcanic gasses

  6. Debris Avalanche or volcanic landslide

  7. Ballistic Projectiles

  8. Tsunami

   
• Lava Flow – are stream like flows of incandescent molted rocks from a crater or fissure.
• Ashfall or tephra fall – are showers of airborne fine – to coarse-grained volcanic particles that fallout from the plumes of volcanic eruption. Ashfall distribution is dependent on prevailing wind direction.
• Pyroclastic flows and surges (pyroclastic density current) - Are turbulent mass of ejected fragmented volcanic materials mixed with hot gasses that flow downslope at very high speeds
• Lahar – is a destructive mudflow on the slope of a volcano. A moving fluid mass composed of volcanic debris and water. It can vary from hot to cold depending on their mode of genesis
• Volcanic gasses – are gasses and aerosols released into the atmosphere, which include water vapor, hydrogen sulfide, sulfur, carbon monoxide, hydrogen chloride, and hydrogen fluoride.
• Debris Avalanche or volcanic landslide - It is a massive collapse of a volcano, usually triggered by an earthquake or volcanic eruption.
• Ballistic Projectiles - These are volcanic materials directly ejected from the volcano’s vent with force and trajectory
• Tsunami – are sea waves or wave trains that are generated by sudden displacement of water (could be generated during undersea eruptions or debris avalanche)