VOLCANIC HAZARD

Cards (37)

  • 24 - Number of Active Volcanoes
  • 42 - Number of Recorded Significant Eruptions for the Past 400 Years
  • 30 Taal Volcano - Highest Number of Recorded Eruptions
  • June 15, 1991 - Date of Mount Pinatubo Eruption
  • Lava - a molten rock or magma that has reached the surface of the Earth.
  • Lava flow - occurs when magma contacts the surface of a volcano and
    erupts or overflows.
  • fluid lava flow - less silica and gas content, high temperature.
  • Viscous lava flow - high silica and gas content, low temperature.
  • Pahoehoe & aa - Types of Lava Flows
  • Water vapor, sulfur dioxide, carbon dioxide, hydrogen chloride and hydrogen fluoride - types of Volcanic Gases
  • sulfur dioxide - negative impacts can form into sulfuric
    acid, a component of acid rain
  • carbon dioxide - negative impacts: causes asphyxiation without warning.
  • monitoring, bulletin or advisories, recommendation, evacuation, public awareness - Mitigating the Negative Effects of Volcanic Gas
  • turbulent ash cloud - riding over the basal flow
  • basal flow - coarse pyroclastic materials
  • fresh or solidified lava, hot volcanic gases, volcanic ash - pyroclastic materials
  • turbulent ash clouds and basal flow - 2 parts of pyroclastic flows
  • pyroclastic materials - also known as tephra
  • pyroclastic materials or tephra - a collective term for volcanic fragments that have been ejected out of a volcano.
  • Soufriere, Pelee, Merapi - types of pyroclastic flow
  • Soufriere type - forms from the collapse of a high vertical column from a highly explosive eruption.
  • Pelee type - occurs when a highly viscous lava dome blocks the opening of a volcano, building pressure until it can no longer be contained and explodes to one side of the volcano.
  • Merapi type - occurs when a lava dome grows too steep over a volcanic crater and falls due to gravitational force.
  • high heat content, high velocity, high volume - Negative Impacts of Pyroclastic Flows
  • HazardHunterPH - an initiative of DOST-PHIVOLCS through
    GeoRisk Philippines.
  • ash - (< 2mm)
  • lapilli - 2-64 mm
  • blocks and bombs - (> 64 mm)
  • ballistic missiles and tephra falls - tephra
  • ballistic missiles - negative impacts: have effects that are in relative proximity to the volcanic source.
  • tephra falls - negative impacts: have widest range of effects amongst all other volcano hazards.
  • mudflow - meaning of indonesian term lahar
  • lahar - It is created when tephras mix with water and form a slurry that flows along the slopes of a topography.
  • Primary lahar - forms when pyroclastic flows occur along areas with bodies of water such as s t reams and rivers .
  • glacier bursts - A particular type of primary lahar that occurs in Iceland and the Andes region.
  • Secondary lahar - forms after an eruption event. Its flows are generated when rain wets unconsolidated tephra and mobilizes them downward.
  • hazard avoidance, hazard modification, hazard warning, hazard response and recovery - mitigation of lahar