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