Volcanic Hazard

1. Republic of the Philippines
Department of Education - National Capital Region
SCHOOLS DIVISION OF PASAY CITY
Address: P. Zamora St., Pasay City
Telephone numbers: 831-6660 831-7498 831-7933
Email address: /deped.pasay@deped.gov.ph
Quarter 1 / Week 4 / Day 17
Objective: Identify the different hazards that Volcanic
Eruption bring as consequence
Earth and Life
Science 11
Prepared by:
GIAN DEL N. ATALIA
Pasay City North High School
Tramo Campus

2. Republic of the Philippines
Department of Education - National Capital Region
SCHOOLS DIVISION OF PASAY CITY
Quarter 1 / Week 4 / Day 17
Objective: Identify the different hazards
that Volcanic Eruption bring as
consequence
Earth and Life
Science 11
Prepared by:
GIAN DEL N. ATALIA
Pasay City North High School
Tramo Campus

4. What to know?
This module will help you identify the different hazards that
Volcanic Eruption bring as consequence
Modules available : tinyurl.com/ELSMODULES

5. On Sunday, January 12, the Taal volcano
began spewing ash, prompting warnings of a
possible explosive eruption. Rumbling sounds
and tremors were also reported. Authorities has
raised the alert to level four – indicating a
hazardous eruption is imminent. Level five, the
highest, means an eruption is taking place.

6. The Philippines lies along the Pacific
Ring of Fire, which causes the
country to have frequent seismic and
volcanic activity.
Many earthquakes of smaller
magnitude occur very regularly due to
the meeting of major tectonic plates
in the region. It is imperative for a
Filipino student to understand a
volcanic eruption’s dangers to
prepare oneself and secure life and
properties.

7. The natural hazards
associated with volcanic
eruptions include lava flows,
falling bombs (Rocks) and
blocks, lightning, ash falls,
pyroclastic flows, debris
avalanche (landslides), and
lahars (volcanic mud flows) .
In addition, fumaroles and
poisonous gas (limnick)
eruptions can occur, and
some large volcanic
eruptions can produce
tsunamis and climate change
DEFINITION OF TERMS

8. Hazards brought upon by Volcanic Eruptions
1. FUMAROLES are openings such as
small vents or cracks in or around a
volcano that emit steam and gases
such as carbon dioxide (CO2), sulfur
dioxide (SO2), and hydrogen sulfide
(H2S) at temperatures varying between
~100 and ~1000 deg. Celsius .
They may persist for centuries or
decades if they lie above a persistent
heat source, e.g., an underlying
sub‐volcanic magma chamber.

9. Hazards brought upon by Volcanic Eruptions
Mount Binuluan Fumaroles
Mt. Binuluan exhibits active volcanism
through numerous fumarole fields,
solfataras and hot springs on its slope.
There were reports of possible
eruptions in 1952 and 1986 (or 1987),
but they are unverified. The fumarole
fields o Of this volcano produce toxic
Gases if inhaled for long periods Of
time. But despite being Dangerous,
natives use this as A tourist attraction
while Still conduction safety measures

10. Hazards brought upon by Volcanic Eruptions
2. LIMNIC ERUPTIONS Volcanoes
release various types of gases including
SO2 and CO2. As described in the earlier
hazard, this kind of eruption is an
odorless and colorless gas that can
suffocate people.
Limnic Eruptions are also called Lake
Overturns, they are rare and only on
various countries with lakes beside the
volcanic area. That is why Limnic
eruptions are considered hazards brought
by volcanic eruptions

11. Hazards brought upon by Volcanic Eruptions
Cameroon Limnic Eruptions
Cameroon has many volcanos, some of them
with lakes in their craters. In the 1980s, limnic
eruptions occurred at two crater lakes, Lake
Nyos and Lake Monoun, in which large
quantities of CO2 that had collected on the lake
bottom suddenly erupted to the surface. 1,800
residents in the three villages at the foot of the
volcano died from lack of oxygen, and there are
concerns that the gas disaster may recur.

12. Hazards brought upon by Volcanic Eruptions
3. LAVA FLOWS are the slow but
destructive flow of lava to residential and
agricultural area.
Because lava flows are extremely hot -
between 1,000-2,000°C (1,800 - 3,600° F) -
they can cause severe burns and often burn
down vegetation and structures.
Lava flowing from a vent also creates
enormous amounts of pressure, which can
crush or bury whatever survives being
burned.

13. 2018 Mt. Mayon Lava
flow Nearly 15,000 people
have fled from villages
around the Philippines’
most active volcano as
lava flowed down its
crater Monday in a gentle
eruption that scientists
warned could turn
explosive. The lava flow
later on damaged millions
of properties and the
lahar caused the same
damage

14. 4. FALLING
BOMBS or
BLOCKS refers to
the molten rocks
from the size of a
baseball (bomb) to
the size of a car
(block) that can be
blasted from an
eruption to more
than a kilometer.

15. 2018 Hawaii Bomb Accident
Although there are no deaths recorded, Bombs and blocks can be a devastating
accident to happen. Molten rocks running into the ocean exploded and threw chunks
of lava onto the Lava Ocean Tours boat (Tour boat of Hawaii), smashing a
basketballsize hole through the boat's roof and raining smaller rocks onto the
decking. Authorities said most of the injuries were burns or scrapes caused when the
hot rocks fall onto the boat and its passengers.

16. 5. Lightning can also be produced in a volcanic eruption. The friction produced by the collision
of the microscopic particles of ash and smoke will produce static electricity and small-scale
lightnings.
Mt. Etna, a stratovolcano on the northeast coast of Sicily, is the largest volcano in Europe. It is
almost in a constant state of eruption. Since 2000 lightning strikes near the summit of the
volcano has killed four tourists

17. 6. Ash Clouds and Ash Falls
Ash is not soft, but is hard and abrasive consisting mostly of pulverized rock and silica. When ash is
ingested into a jet engine it melts, and then is sucked into cooler regions of the engine where it creates a
“flame out”, i.e., total engine failure. There are reports of as many as 100 jets having encountered ash
clouds. Ash is also dense and can mix with water vapor to increase its density. It can flatten and cover
entire cities in a matter of minutes that is why communities are forced to evacuate at least 30
KILOMETERS from the volcano

18. 7.Lahar, an Indonesian term, describes a hot or cold mixture of water and volcanic rock fragments flowing down
the slopes of a volcano or river valley. Lahars vary widely in size but can reach up to ~30 feet or more (tens of
meters) in thickness and ~330 feet or more (hundreds of meters) in width. Such large flows can travel at speeds
in excess of ~30 feet/second (tens of meters per second).
Lahars pick up material as they travel, which can cause damage to structures in their path. The figure below is
an example of the destruction of Mt. Pinatubo , the 2nd largest volcanic eruption of the 20th century.

19. 8. Tsunami
The term tsunami comes from the Japanese and literally means "harbor wave". The famous
1883 eruption of Mt. Krakatoa produced a series of tsunamis that devastated the
surrounding coastal areas destroying some 165 villages and killing over ~36,000 people.
The figure below is a computer simulation of the Tsunamis produced by the volcano and
how graphically devastating they were.

20. 9. Pyroclastic flows are relatively common
during eruptions of felsic (Iron-related) to
intermediate composition magma. They are
mixtures of hot gases, rock fragments, and
rock debris.
During the giant eruption of Mt. Pinatubo,
huge pyroclastic flows—mixtures of hot ash
and gases denser than air—swept down the
flanks of Pinatubo as far as 16 km (10 miles)
from its old summit. These intensely hot ash
flows sterilized 400 square km (154 square
miles) of land around the volcano, filling
valleys with high-temperature deposits as
much as 200 metres (660 feet) thick.
Most of the instant deaths that happened
that day were result of pyroclastic materials
rapidly spreading around the residential
areas of the said volcano. The figure is a
picture of its huge pyroclastic explosion.

21. ● There are nine (9) main Hazards that are brought upon by volcanic
eruptions
● Fumaroles and Limnic Eruptions are gaseous hazards that can suffocate
and poison people
● Lava flows and Bombs and Blocks are hot objects projected by the
Volcano that can cause serious damage
● Pyroclastic materials and Ashfall can be spread through air and can
devastate huge areas of land and residences, along with flowing lahar.
● Lightning and Tsunamis can be produced, as long as the conditions of
environment, atmosphere, and bodies of water are met.
SUMMARY

22. Republic of the Philippines
Department of Education - National Capital Region
SCHOOLS DIVISION OF PASAY CITY
Quarter 1 / Week 4 / Day 17
CONGRATULATIONS!
You may now answer the exercises in
your module. God Bless!
Earth and Life
Science 11
Prepared by:
GIAN DEL N. ATALIA
Pasay City North High School
Tramo Campus