DRRR

• Signs of impending volcanic eruption


  • Increase in the frequency of volcanic quakes with rumbling sounds
  • Occurrence of volcanic tremors
  • Increased steaming activity
  • Change in color of steam from white to gray
  • Crater glow due to presence of magma at or near the crater
  • Ground swells (or inflation), ground tilt and ground fissuring due to magma intrusion
  • Localized landslides, rock falls and landslides from the summit area that are not attributed to heavy rains
  • Noticeable increase in drying up of vegetation around the volcano's upper slopes
  • Increase in temperature of hot springs, wells and crater lake near the volcano
  • Noticeable variation in the chemical content of springs, crater lakes within the vicinity of the volcano
  • Drying up of springs/wells around the volcano
  • Development of new thermal areas and/or reactivation of old ones; appearance of solfataras (craters with sulfur gas)
• Parameters used to monitor volcanoes

  • Ground deformation
  • Seismic Activity
  • Gases
  • Sensory observations (by people living near volcano)
• Volcanoes are scattered from north to south of the Philippines
• Volcanic Alert Level


  Alert Level 0 (lowest) to Alert Level 5 (highest)
• Active volcano


  A volcano that has had at least one eruption during the past 10,000 years
• Erupting volcano


  An active volcano that is having an eruption
• Dormant volcano


  An active volcano that is not erupting, but supposed to erupt again
• Extinct volcano


  Has not had an eruption for at least 10,000 years and is not expected to erupt again in a comparable time scale of the future
• Figure 5.4 shows numerous volcanoes almost parallel to the trenches that define the territorial bounds of the country
• Dormant volcanoes coded in green have not shown or may never show any signs of activity in terms of tremors, gas emissions, and heat release in the near future
• Active volcanoes within the last 600 years are indicated in red triangles
• Potentially active volcanoes shown in yellow triangles are categorized by volcanologists and geologists as those that are not currently exhibiting signs of eruption but have a high possibility of any form of seismic activity in the future
• Some of the numerous active volcanoes traversing the entire country are considered higher in risk
• Areas of Camiguin, Sulu, Biliran, Albay, Bataan, Sorsogon, South Cotabato, Laguna, Camarines Sur, and Batanes are all at risk of volcanic eruption