volcanic hazards Flashcards
(19 cards)
____________ are phenomena arising from volcanic activity that pose potential threat to persons or property in a given area within a given period of time.
Volcanic hazards
The Philippines has ___ active
volcanoes.
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The government agency who monitors this type of hazard is called __________
PHIVOLCS or Philippine Institute of Volcanology and Seismology
Volcanic-related Hazards
I. Lava Flows
II. Ash fall or Tephra falls
III. Pyroclastic flow and surges
IV. Lahars
V. Volcanic gases
VI. Volcanic landslide
VII. Ballistic Projectiles
VIII. Tsunami
_____ can burn. The
intense heat of _____
melt and burn. As ____
flows are hot and
incandescent, areas it
covers are burned
(forest, built up areas,
houses).
Lava Flow
These are showers of airborne fine- to coarse-grained volcanic particles
that fallout from the plumes of a volcanic eruption; ashfall distribution/ dispersal is dependent on prevailing wind direction
Ashfall or Tephra Fall
_________ endanger life and
property by During peak of eruption with excessive ash, can cause poor or low visibility (driving, slippery roads)
Ashfall
These are turbulent mass
of ejected fragmented
volcanic materials (ash and
rocks), mixed with hot
gases (200oC to 700oC to
as hot as 900oC) that flow
downslope at very high
speeds (>60kph).
Pyroclastic Flow
__________ are the more dilute, more
mobile derivatives or pyroclastic flows.
Surges
These are rapidly flowing thick
mixture of volcanic sediments
(from the pyroclastic
materials) and water, usually
triggered by intense rainfall
during typhoons, monsoons
and thunderstorms.
Lahars
______ can
occur immediately after an
eruption or can become long-
term problem if there is
voluminous pyroclastic
materials erupted
Lahar
Gases and aerosols released into the
atmosphere, which include water vapor, hydrogen sulfide, sulfur
dioxide, carbon monoxide, hydrogen
chloride, hydrogen fluoride
Volcanic Gases
These are volcanic materials directly
ejected from the volcano’s vent with
force and trajectory
Ballistic Projectiles
Sea waves or wave
trains that are generated by sudden
displacement of water (could be
generated during undersea eruptions or debris avalanches)
Tsunami
Impending Signs of a
Volcanic Eruption
I. Ground deformation
II. Geochemistry: Gas emissions
III. Seismic activity
IV. Monitoring signs of impending eruption by remote sensing
V. Sensory observations
__________ are some volcanic
gases that pose hazard to people,
animals, agriculture and property.
Sulfur dioxide (SO2), carbon
dioxide (CO2), and hydrogen
flouride (HF)
_____ can lead to acid rain.
SO2 Sulfur dioxide
High concentrations of ______ which is
colorless and odorless can be
lethal to people, animals and
vegetation.
carbon dioxide
_____ compounds
can deform and kill animals that
grazed on vegetation covered
with volcanic ash.
Fluorine
