GROUP 1

AT THE END OF THIS MODULE , I CAN:

● Explain various volcano- related hazards.
● Differentiate among different volcano hazards.
● Recognize and identify signs of an
impending volcanic eruption.
● Explain and interpret different volcano hazard
maps
● Apply appropriate measures/ interventions before,
during , and after a volcanic eruption.
Volcanoes -are opening in Earth's crust
that allows the energy from the interior
of Earth to escape to the surface. The
energy in the magma that goes out are in
the form of lava, ash, and gas.
There are volcanoes because Earth's crust is broken
up into tectonic plate. Most volcanoes are found on
the edges of plates where one plate connects to
another . For example, the Pacific Plate has active
volcanoes strategically located on its edges, from
which the term " Pacific Ring of Fire" came about.
Another example is the Mid- Atlantic Ridge located on
the edge of the Eurasian Plate and the North
American Plate. This area also has volcanoes at the
bottom of the Atlantic Ocean.
Most of the islands in the Philippines are volcanic in
origin. The Philippines is located near the Pacific Ring of
Fire, and that the Philippines Plate's western edge (
Philippine Fault System) runs from the north all the way
to the south of the country. Give another fact that the
plate edge can branch out to several smaller faults and
fissures, these cracks and openings are where
volcanoes have formed. According to PHILVOLCS , there
are more than 20 historically active volcanoes in the
country that were active in the last 600 years.
BIG IDEA!
The location of the Philippines in the Pacific Ring
of Fire is in the area that is closer to the mantle .
This explains why there are numerous volcanoes
all over the country .
Volcanic hazards are volcano-
related phenomena that pose
potential threat or negative impact
to life, property, and the
environment in a given period of
time. The following are some
potential volcano-related hazards:
 Lahar
- Is an Indonesian term for the mixture
of water, pyroclastic materials, and rock
fragments flowing down a volcano or
river valley.
- When lahar flows from a volcano, it is
highly destructive to anything in its path.
-Lahar is powerful enough to remove or
carry away trees, boulders, and logs.
Buildings, houses, and other structures
can be partially or completely buried by
the turbulent flow of lahar.
Many towns were buried in lahar during
the 1991 eruption of Mt. Pinatubo.
ONE OF THE GREATEST VOLCANIC HAZARDS IS LAHARS. LAHARS ARE
SIMILAR TO PYROCLASTIC FLOWS BUT CONTAIN MORE WATER. LAHARS
FORM ;
1) from debris avalanches that contain water from snow and ice which,
when released, mixes with loose debris to form a lahar,
2) from pyroclastic flows and surges which release water that mixes
with debris,
3) from pyroclastic flows which dilute themselves with river water as
they travel downslope,
4) from natural dam failure (i.e. a lava flow dam or crater lake), and
5) from rainfall on loose material such as ash. Lahars that contain 20
to 60 percent sediment are usually very turbulent. Lahars that contain
greater than 80 percent sediment usually flow more smoothly (laminar
flow). These smooth flowing lahars usually travel much faster than
their turbulent counterparts and can float boulders, cars, buildings,
and bridges (Philippines, 1992).
LAHARS AND EXCESS SEDIMENT CAUSE SERIOUS ECONOMIC AND
ENVIRONMENTAL DAMAGE TO RIVER VALLEYS AND FLOOD PLAINS
Large lahars can crush, abrade, bury, or carry away
almost anything in their paths. Buildings and valuable
land may be partially or completely buried. By
destroying bridges and roads, lahars can also trap
people in areas vulnerable to other hazardous volcanic
activity, especially if the lahars leave fresh deposits
that are too deep, too soft, or too hot to cross.
RESEARCH ADDRESSES LAHAR TRIGGER MECHANISMS, FLOW
DYNAMICS, FORECASTING, AND IMPROVED WARNING SYSTEMS
To understand lahars, scientists observe and quantify what
happens when these events occur naturally, derive equations to
describe lahar behavior, and perform controlled experiments in
a 310-foot (95-m) long debris flow flume. The results help us to
understand flow dynamics and provide a foundation for a
mathematical and computational model called D-Claw.
D-Claw is a numerical software package that is used to simulate
fluidly-flowing geologic events like landslides aover time. nd
lahars. The model predicts how a flow moves across terrain
• This is composed of bits and pieces of pulverized rock,
minerals, and volcanic glass generated from the volcanic
eruption. These fragments measure less
• than 2 mm (0.079 inches) in diameter. Volcanic ash is usually
spewed out from explosive eruptions when dissolved gases
in magma expand and go out violently into the atmosphere.
The impact from the released gas shatters the magma and is
forced out into the atmosphere where it hardens into
fragments of volcanic rock and glass.
• Sometimes, ash clouds are formed especially when the
atmosphere is humid and dry.
• Volcanic ash is hard, it does not dissolve in water and is
abrasive and corrosive – this why it can clog jet engines,
shut off their cooling systems, and cause aeroplane crashes.
When ash clouds are formed, they can
travel farther and cover a larger radius.
Sometimes, local climate is affected as the
clouds block the sunlight in the affected
region. Depending on the density and
amount of the ash clouds, the change in
local climate may last longer. In time, the
ash falls slowly and can destroy structures
and buildings by putting more weight on the
roof, causing a collapse. Or the ash can
corrode building materials or destroy
agricultural land.
The fine particles of ash can also clog air filters
in vehicles and machinery to cause malfunction
or overheat. On roadways and airport runways,
wet ash can be very slippery, making these
roads impassable or treacherous. Finally,
airborne particles can have adverse health
effects on plants, animals, and humans. The
most common health risk associated with ash
fall is respiratory diseases related to asthma,
bronchitis, and emphysema. Dehydration,
starvation, and poisoning, on the other hand, are
among the health problems of animals exposed
to ash fall.
TAAL ASH FALL
PYROCLASTIC FLOW
This refers to the fast-moving fluidized mass of rock
fragments and gases. When pyroclastic flow travels
down a volcano, it maintains a very high temperature,
burning everything in its path. In fact, in the Mt. Pinatubo
eruption in 1991, some pyroclastic flows had
temperatures of about 750°C. Such high temperatures
instantly burn man-made structures and vegetation.
Pyroclastic flows can easily incinerate, burn, and
suffocate humans and animals. The gases that come with
the pyroclastic flow can explode and may even cause
acid rain. Like lahar, the threat of pyroclastic flows is far
reaching. They can travel to long distances, thus
producing greater hazards.
A hot (typically >800 °C, or >1,500 °F ), chaotic
mixture of rock fragments, gas, and ash that
travels rapidly (tens of meters per second) away
from a volcanic vent or collapsing flow front.
Pyroclastic flows can be extremely destructive and
deadly because of their high temperature and
mobility.
PYROCLASTIC FLOW DURING THE MT. PINATUBO ERUPTION
BIG IDEA FOR ASH FALL
Ash fall is comprised of fragments of
rocks, minerals, and glass that have
hardened while escaping into the
atmosphere. When they fall to the ground,
they can cause clogs and corrosion of
structures, and health problems of
humans.
BALLISTIC PROJECTILES
WHAT IS BALLISTIC PROJECTILE ?
• This is the rock fragment that is ejected from a volcano during its explosive
eruption.
• It is like a cannonball that travels fast in the air. According to USGS,
volcanic projectiles can be bombs and blocks.
• It is considered a block if the projectile or rock fragment is solid when
ejected. But, it is launched in a partially molten or molten state, it is a
bomb.

The impact of projectiles poses a serious hazard to humans, plants, and

animals, and properties.
Ballistic projectiles can travel as far as 5 km or even further, depending on the
magnitude of
explosion.
 WHAT IS VOLCANIC GAS ?
• This consists of sulfur dioxide and hydrogen sulfide, which are
poisonous and hazardous to organisms.
These are the main constituents of the magma that is spewed out
during an eruption. The excessive composition of these chemicals
in the air can cause acid rain.

Plants, buildings, and other structures that are exposed to acid rain are
prone to corrosion.
Volcanic gas also causes respiratory problems and other health risks.
Communities that are exposed
to volcanic eruption may experience asthma or difficulty in breathing.
LAVA FLOW
 WHAT IS LAVA FLOW?
• This is molten rock that pours down from the slopes of the
volcano. It is different from pyroclastic flow in that lava flow
is denser and hence moves more slowly. Thus, it gives more
time for animals and humans to move away from its path,
unlike pyroclastic flow that may leave no time for organisms
to react.
• Lava flows can kill vegetation and destroy property by
burning homes and
destroying infrastructure, such as bridges and roads. Forest
fires can be ignited by lava flow.
SIGNS OF AN IMPENDING
VOLCANIC ERUPTION
Recent advancements in predicting and
monitoring volcanic activity have
significantly reduced volcanic risks. There
are a number of warning signs when an
active volcano is about to erupt. Here are
some of them:
A volcanologist, or volcano scientist, is a geologist
who focuses on understanding the formation and
eruptive activity of volcanoes.
1. Occurrence of tremors or increase in
the frequency of small earthquakes.
A seismogram is a record of the seismic waves from an earthquake.
A seismograph or seismometer is the measuring instrument that
creates the seismogram.
 2. Deformation in the ground manifested by
changes in ground elevation (tilting) and formation
of cracks or openings (ground fissuring).
 All these observations can support the
speculation that rocks are being pushed
upward and out of the crater of the volcano.
A tiltmeter is a sensitive inclinometer designed to
measure very small changes from the vertical
level, either on the ground or in structures.
3. Increase in the amount of volcanic gases
and in temperature, which may indicate that
the magma has gone closer to the surface.
4. Glow of volcanic crater due to the
presence of magma.
5. Increase in steam emission coming
from volcanic openings, fissures, or
hot springs.
A correlation spectrometer (COSPEC) is designed
to measure the amount of sulfur dioxide in a
passing air mass (or volcanic plume).
6. Thermal changes within the
surroundings of the volcano.
 A pyrometer or infrared thermometer is a device for non-
contact temperature measurement. The pyrometer rests in
terms of physics on the evaluation of electromagnetic
radiation radiated from the object to be measured,
proportional to the object temperature.
 The thermal camera uses infrared-sensitive sensors to
detect the IR energy and converts it into a thermal image.
It also assigns colors to the differing temperatures to
indicate variations, such as hot spots.
 7. Change in the color of nearby
vegetation and lakes (The color changes
in vegetation and lakes are due to the
dissolution of minerals and other acidic
chemicals from the volcano that found
their way into these open areas.)
 pH (known as Potential of Hydrogen, a quantitative measure of the
acidity or basicity of aqueous or other liquid solutions) affects the
amount of nutrients and chemicals that are soluble in soil and water.
pH meter is an instrument used to measure acidity or alkalinity of a
solution.
8. Landslides and rock fall
not due to heavy rains.
 9. Drying up of springs and
freshwater sources around the
volcano.
 A water level gauge is a device used to
measure the level of water in a container or
body of water.
GPS can be used in monitoring volcanic activity by
measuring the deformation of the ground caused by
magma movement beneath the Earth's surface.
INTERPRETING VOLCANIC HAZARD MAPS
Volcanoes are scattered from north to south of the Philippines.
Those coded in green indicate dormant volcanoes which, based on
their history, have not shown or may never show any signs of
activity in terms of tremors, gas emissions, and heat release in the
near future. Other volcanoes are known to be active within the last
600 years and these are indicated in red triangles. PHIVOLCS has
been closely monitoring the active volcanoes to alert communities
in the immediate vicinity of any danger. The last type of volcanoes
are considered potentially active, shown in yellow triangles, which
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. PHIVOLCS has listed down these
volcanoes that may cause disaster to nearby
communities and properties because of the
potential strength in their seismic activities.
Areas of Camiguin, Sulu, Biliran, Albay, Bataan,
Sorsogon, South Cotabato, Laguna, Camarines
Sur, and Batanes, which are all at risk of
volcanic eruption.
 PRECAUTIONARY AND SAFETY
MEASURES BEFORE, DURING, AND
AFTER VOLCANIC ERUPTIONS
 Although they are often adored for their beauty and
fascinating nature, some volcanoes bring about disastrous
effects when they erupt. How can people prepare for the
danger that volcanoes bring? Below are some precautionary
measures that people can do before, during, and after a
volcanic eruption.
Before an Eruption :
1. Stay updated with the local news.
2. Learn about your community warning systems and
emergency plans. Have a meeting with all family members
and make a family emergency preparedness plan. Make sure
thatThiseach
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 ADDITIONAL INFORMATIONS ON HOW TO
PREPARE BEFORE A VOLCANIC ERUPTION
- Close and lock all windows and outside doors. Turn off all
heating and air conditioning systems and fans. Close the
fireplace damper. Organize your emergency supplies and
make sure household members know where the supplies
are.
-Be prepared either to shelter or to evacuate. Develop an
evacuation plan and a sheltering plan for yourself, your
family, and others in your household. Review the plans and
make
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•First aid kit and manual
•Emergency food and water
•Manual (nonelectric) can opener
•Essential medicines
•Sturdy shoes
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•Battery-powered radio
-Follow evacuation orders issued by local
authorities and remind family members of your
disaster plan. Stay in the evacuation center until
further instructions are given by authorities.
-If told to stay indoors, place a damp cloth over your
windows and, if possible, over your doors. Make
sure all windows, doors and other vents are kept
closed to prevent entry of ash and other materials
spewed out by the volcano. The wet cloth will help
keep fine volcanic particles from entering your
house.
-Wear long-sleeved shirts and long pants.
-Use googles to protect your eyes.
-Use a dust mask or hold a damp cloth over your
face to prevent inhalation of ashes and other
volcanic particles. This will also help you breath
easier.
-Avoid low-lying regions and river areas near the
volcano, Volcanic debris and ash will be carried
by the wind and gravity.
-Listen to a battery-operated radio for the latest
emergency information.
1. Wait for the announcement from local authorities that it is
safe to return to your house.
2. Inspect your house carefully for any damage before you
enter it. Do not enter your If you smell gas, either a leak is
present or the authorities have declared it unsafe.
3. If you or a family member has a respiratory ailment such
as asthma or bronchitis, Stay away from volcanic ashfall
areas. Volcanic ash can cause severe damage to the
respiratory system as well as irritation to the skin and the
eyes.
4. Wear a dust mask. gloves and goggles while cleaning the
debris and ashfall on the roof. of your house to avoid
further damage.
5. Check electrical wiring, appliances, and gas tanks before
using them.
6. Boil water before drinking it. Groundwater pipes may have
been contaminated volcanic particles.
7. Stay informed and listen for emergency updates and news.
In addition to the previously mentioned steps, it's
critical to be informed about any potential long-term
consequences of a volcanic eruption. The environment,
including water quality, agriculture, and wildlife, can be
significantly impacted by volcanic ash. Air travel may
also be impacted, and businesses and tourism may be
negatively impacted. The formation of new land, such
as islands or volcanic cones, can occasionally result
from volcanic eruptions. It's critical for governments
and communities to have plans in place for handling
the aftermath of a volcanic eruption, including keeping
an eye out for lingering dangers and offering
assistance to those who were impacted. Future
eruptions can be predicted and their effects reduced
with the aid of research and monitoring of volcanoes.