Enumerates what is volcanic Eruption

1. Volcanic
Eruption

2. Objectives
Explain the nature and process of a
volcanic eruption.
Identify the different hazards associated
with volcanic eruption,and
Discuss how to reduce risk and prepare
for a volcanic eruption.
2
By the end of this lesson, the
students must be able to:

3. Introduction
The Philippines is known for its beautiful volcanoes.
Foreign and local tourists go Tagaytay to see the Taal Volcano, the
volcano with a lake and within the lake. The mayon volcano in
Albay, Which is famous for its almost perfect conical shape, has
many visitors as well.
Aside from their contribution to the tourism industry,
volcanoes also help improve the quality of hte surrounding soil by
providing nutrient for crops such as abaca in Bicol. Their
geothermal component is also excellent source of energy and
recreational facilities.
However, these volcanoe can also pose danger. When
Mayon volcano erupted in 1814, it claimed the lives of roughtly
1,200 people (Olan, 2015). The eruption of Mt. Pinatubo in1991
buried adjacent communities in lahar and affected the global
climate. The hazards brought by a volcanic eruption such as ash
fall, poisonous gases, and lahar can harm not just the communities
surrounding the volcano but also the people living in areas distant
from the site.
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Taal Volcano
Mayon Volcano

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UNDERSTANDING
OF
VOLCANIC
ERUPTION

5. Takes place when
two plates converge.
Is a vent on the earth’s
surface that opens downward
to a pool of molten rock,
debris, and gases.
VOLCANO
SUBDUCTION
Is the place where the
two plates converge and the
volcano is formed (DOST-
PHIVOLCS, n.d.).
SUBDUCTION
ZONE
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6. 6
The thickness of the magma caused by its silica content makes it difficult for gases to be
released easily. A MAGMA CHAMBER forms inside the steep cone and this collects the
gases. When the gases accumalate, the volcano erupts because the pressure rises
within the chamber as it cannot contain the magma.

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CLASSIFICATIONS
OF
VOLCANOES

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is currently
erupting or is showing
signs of volcanic
eruption. It should
have also erupted
within the last 600
years
ACTIVE
VOLCAN
O

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is one which has
erupted and then
entered a long period of
inactivity, Mt. Pinatubo
was a dormat volcano
for about 600 years until
it explosively erupted in
1991
Potentially
Active Volcano

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is on that has not shown
any sign of activity for a
long period. It has no record
of volcanic eruption in the
past thousand years, An
example of an inactive
volcano is Mt. Cabalian in
Leyte.
Inactive
Volcano

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VOLCANIC
ERUPTION
HAZARDS

12. 12
LAVA FLOW
Lava flow is a mass of
magma that flows down the slope
of the the volcano at a rate of 3
kilometer per ay (slightly high
viscosity) or 45 kilometer per hour
(low viscosty). The speed of a lava
flow depends on the local
topography; steep slopes
encourage faster and longer flows
than gentle slopes or terrain. Lava
flows can cause injuries and burn
structures and vegetation.

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Pyroclastic flow refers to hot
dry masses of fragmented volcanic
materials that move along the slope and
in contact with ground surface at speed
greater than 60 kilometers per hour.
This flow from a collapsed eruption
column or lava dome. O n the other
hand, pyroclastic surges are trubulent
low-concentration density currents of
gases, rock de and in some cases,
water, that move above the ground
surface at high velocities.
PYROCLASTIC FLOW

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Tephra falls are showers of fine
to coarse-grained volcanic materials
and other airborne products of a
volcanic eruption. The diameter of the
particles can be less than 2
millimeters (ash), 2 to 64 millimeters
(lapilli), or greater than 64
millimeters (blocks and bombs)
(DOST- PHIVOLCS, n.d.). The ash can
reach distant places since it is carried
by the wind. The ash from the Mt.
Pinatubo eruption reached as far as
Vietnam. Tephra falls can cause
pollution, health problems, poor
visibility, and disruption of electricity
and communication lines.
TEPHRA FALLS

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BALLISTIC
PROJECTILES
Ballistic projectiles are rocks that
are released into the air by an
erupting volcano. These land
within 2 kilometers of the vent
but can travel as far as 5
kilometers or further if the
eruption is very explosive

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VOLCANIC GAS
Volcanic gas is one of the basic
components of magma or lava. Active
and inactive volcanoes may release
gases to the atmosphere in the form
of water vapor, hydrogen sulfide,
sulfur dioxide, carbon monoxide,
carbon dioxide, hydrogen chloride,
and hydrogen fluoride. Hydrogen
chloride and hydrogen fluoride are
released by volcanic activity and
dissolved in water droplets in steam
clouds. This creates acid rain that can
harm plants, marine life, and
infrastructures

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LAHAR
Lahar is a flowing mixture of
volcanic debris and water. It is classified
into two: the primary or hot lahar that is
associated directly with volcanic eruption
and the secondary or cold lahar caused
by heavy rainfall, Lahar can destroy and
bury structures and communities, just
like what happened after the eruption of
Mt. Pinatubo. On October 1, 1995,
typhoon rains caused lahar that was
formed from 50 million cubic meters of
volcanic debris. These buried
Cabalantian, one of the barangays in
Pampanga which had initially escaped
lahar that had affected other areas since
the eruption. In six hours, 2,300 houses,
500 vehicles, and countless people were
buried

18. VOLCANIC
ERUPTION
PREPAREDNESS
Unlike an earthquake, a volcanic eruption
has warning signs that can be detected
and can help people prepare for the
disaster. Here are the precursors of an
impending eruption according to
PHIVOLCS.
18

19. 1 2 3 4 5
Increase in the
frequency of
volcanic quakes
with rumbling
sounds; occurrence
of volcanic tremors
Increased
steaming activity;
change in color of
steam emission
from white to gray
due to entrained
ash
Ground swells (or
inflation), ground
tilt and ground
fissuring due to
magma intrusion
Crater glow due to
presence of
magma at or near
the crater
Localized
landslides,
rockfalls, and
landslides from the
summit area not
attributable to
heavy rains
VOLCANIC ERUPTION PREPAREDNESS
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20. 6 7 8 9 10
Noticeable increase
in the extent of
drying up of
vegetation around
the volcano's upper
slopes
Increase in the
temperature of hot
springs, wells
(e.g., Bulusan and
Canlaon), and
crater lake (e.g.,
Taal) near the
volcano
Drying up of
springs/wells
around the volcano
Noticeable
variation in the
chemical content of
springs and crater
lakes within the
vicinity of the
volcano
Development of
new thermal areas
and/or reactivation
of old ones;
appearance of
solfataras
VOLCANIC ERUPTION PREPAREDNESS
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21. MAYON VOLCANO WAARNING AND
ACTION PLAN
Warning Level Criteria Interpretation Required Action
0 No Alert, Quiet Normal None
1 Low level Unrest Abnormal Monitoring
2 Low to moderate
level of seismic and
unrest
Alarming Monitoring and
review of
preparedness plan
3 relatively high unrest Critical Execute Evacuation
Plan A
4 Intense unrest Eruption Imminent Execute Evacuation
Plan B
5 Eruption in progress Eruption in progress Evecute Response
Works
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22. Mandatory
evacuation in the 6-
km radius
permanent zone
Forced evacuation in
thhe hgh-risk zone
Pre-emptive
evacuation in the
eastern seaboard
voluntary evacaution
for inderict victims
(Daep,n.d.)
They also have an evacuation plan based on the
risk assessment of the areathat can be affected
by the eruption. The plan Includes
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1
2
3
4

23. To mitigate the impact, PHIVOLCS formulated guidelines on
what should be done before and during a volcanic eruption
REDUCING THE IMPACT
OF ERUPTION
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24. What to do Before a
volcanic eruption
1. Learn about your community,s warning system. If there is none, work
with your community in developing one.
2. Make an evacuation plan. You have to get to higher ground away from
the eruption. Plan a route out and have a back-up route in mind in
case family members are s from one another during the eruption.
separated
3. Create an emergency communication plan. Ask a relative or a friend
living outside the danger zone to serve as your contact, as it would be
easier to reach them after the disaster. Make sure that everyone in the
household knows that person's name, address, and phone number.
4. Prepare a disaster supply kit. This should include items such as a first
aid kit, a mask, a can opener, a flashlight with extra batteries or
preferably a crank model, any necessary medication, sturdy shoes,
goggles or another form of eye protection, and a battery. powered
radio. Ensure that everyone in your family knows where the emergency
supplies are located.
5. Contact your local emergency management office or the Red Cross
chapter for more information on volcanoes.
6. Although it may seem safe to stay at home and wait for the start of an
eruption, doing so could be dangerous. The rock debris from a volcano
can break windows and set the house on fire. Stay safe by following
the authorities' instructions and leaving the area before the disaster
begins.

25. What to do during a
volcanic eruption
1. Listen to a battery-operated radio or television for the latest emergency
information.
2. Follow the evacuation order issued by authorities.
3. Avoid areas downwind and river valleys downstream of the volcano.
4. If caught indoors:
a) Close all windows, doors, and dampers.
b) Put all machinery inside a garage or barn.
c) Bring animals and livestock into closed shelters.
5. If trapped outdoors, seek shelter indoors.
a) Protect yourself. Wear long-sleeved shirts and a pair of pants. Use
goggles or dust mask to protect your eyes or hold a damp cloth over
your face.
b) If caught in a rock fall, roll into a ball to protect your head
c) If caught near a stream, be aware of mudflows. Move up slope,
especially if you hear the roar of a mudflow..
6. Protect yourself during ash fall.
a) Wear long-sleeved shirts and long pants.
b) Use goggles to protect your eyes.
c) Use a dust mask or hold a damp cloth over your face for you to
breathe.
d) Keep car or truck engines off.

26. What to do during a
volcanic eruption
7. Remember to stay out of the area defined by government officials as a
restricted zone. Effects of a volcanic eruption can be experienced many
miles away from a volcano. Mudflows and flash flood, fires, and even
deadly hot ash flow can reach you even if you cannot see the volcano
during an eruption. Avoid river valleys and low lying areas. Trying to watch
an erupting volcano up close is not safe at all.
8. If possible, stay away from areas of volcanic ash fall.
9. When outside:
a) Cover your mouth and nose. Volcanic ash can irritate your respiratory
system.
b) Wear goggles to protect your eyes.
c) Keep skin covered to avoid irritation from contact with ash.
d) Clear roofs of ash fall. Ash fall is very heavy and can cause buildings
to collapse.
e) Exercise great caution when working on a roof.
f) Avoid driving in heavy ash fall. Driving will stir up more ash that can
clog engines and stall vehicles.
g) g. If you have a respiratory ailment, avoid contact with any amount of
ash. Stay indoors until local health officials advise that it is safe to go
outside.

27. THANK YOU

28. Table 1
Members:
Dagohoy
Castre
Demerin
Antonio
Estrabon
Margarse
Oliveros
Melgarejo
Aguil
Dioso
Badi
Arsigono