ST. MARY MAGDALENE COLLEGES OF LAGUNA
Purok 1, Uwisan, Calamba City
SENIOR HIGH SCHOOL
LEARNING MODULE IN EARTH AND LIFE SCIENCE
NAME
GRADE AND SECTION
TEACHER PHILIP C. CLUTARIO
5
MODULE NUMBER
TRACKING NUMBER
UNIT 1: EARTH AND EARTH SYSTEMS
CONTENT STANDARD 
PERFORMANCE 
STANDARD
MOST ESSENTIAL 
LEARNING
COMPETENCIES 
The learners demonstrate an understanding of the subsystems
(geosphere, hydrosphere, atmosphere, and biosphere) that make up the
Earth.
The learners shall be able to conduct survey or design a study to assess
the possible hydrometeorological hazards that the community may happen.
Using hazard maps identify areas prone to hazards brought about by
earthquakes, volcanic eruptions, and landslides
Identify human activities that speed up or trigger landslide
Understanding Geological Hazard Maps
How can you determine if a certain location is prone to geological hazards?
Geological Hazard Map
A geological hazard map is a map indicating the areas that are vulnerable to hazards caused by earthquakes,
volcanic eruptions, and landslides. It is a tool used by scientists and local government authorities to anticipate
any hazard that a geological event may bring. It also helps the public be informed and prepared for the
geological hazard.
How do you read a geological hazard map?
You must take note of the following elements in studying the geological hazard map:
Map Title
The map title indicates what type of information is being presented by the map. For example, the title “tsunamiprone areas” indicates that the map presents the places along the coastal areas that are prone to tsunami
hazards.
Symbols and Legend
 Symbols are the points, lines, shapes, and colors used on the map. For example, a line may indicate
faults or tsunamis while a triangular shape may represent a volcano.
 The legend tells you specifically what these symbols mean.
 Source Make sure that the source of your map is a credible institution.
 Hazard maps are produced by government agencies like PhiVolcS (Philippine Institute of Volcanology
and Seismology), DOST (Department of Science and Technology), and DENR (Department of
Environment and Natural Resources).
 Private research institutes like the Manila Observatory also generate maps. With the use of the Internet,
these maps can be viewed online on their websites.
Earthquake Hazard Map
The map below shows the earthquake-prone areas in the Philippines. Based on the legend, the different
locations are colored depending on the number of earthquake hits for the past 30 years. For example, Baguio
City (Benguet), which is found in the northern part of Luzon, experienced 76-100 earthquakes. Meanwhile,
Puerto Princesa City (Palawan), which is in the Southwest of Luzon, experienced fewer earthquakes (0-11).
The top ten provinces that are most prone to earthquakes are:
Surigao Del Sur
La Union
Benguet
Pangasinan
Pampanga
Tarlac
Ifugao
Davao Oriental
Nueva Vizcaya
Nueva Ecija
PAGE 1 MODULE 3
ST. MARY MAGDALENE COLLEGES OF LAGUNA
Purok 1, Uwisan, Calamba City
SENIOR HIGH SCHOOL
LEARNING MODULE IN EARTH AND LIFE SCIENCE
Surigao del Sur, along with Davao Oriental, are earthquake-prone because they are located along the
Philippine Trench and because of nearby active fault lines.
Deep-focus earthquakes that are experienced in La Union and Pangasinan are due to the Manila Trench, while
shallow earthquakes in these areas together with Nueva Vizcaya, Nueva Ecija, and Benguet are generally due
to their location along the Philippine Fault Zone. Although Ifugao experienced fewer earthquakes in the past, it
is still very vulnerable to future earthquakes.
In addition, the size of the red dots indicates the magnitudes of the earthquakes that hit the area for the past 30
years. For example, a large dot in Manila indicates that the magnitude of the earthquake is 7.3 to 7.6. On the
other hand, a tiny dot, as seen in areas around Palawan, means that the magnitude of earthquake is around
5.5 to 6.2.
Activity 1
Find a map of the Philippines and compare it to the earthquake-prone area map. Then answer the following
questions:
1. Which is more prone to earthquakes, Pampanga or Zamboanga?
2. Which town experienced a greater magnitude earthquake, Panay or Mindoro?
Tsunami Hazard Map
The following map shows the places along the coastal areas in the Philippines that are prone to tsunami
hazards. Cyan, magenta, and yellow lines indicate the potential of the tsunami and the tsunami generators.
When the earthquake occurs in the Philippines, then tsunami is locally generated. On the other hand, an
earthquake that occurs outside the country may be a foreign tsunami generator for the Philippines. Majority of
the coastal areas in Luzon (with the exception of Palawan and northern islands) have a high tsunami potential
with historical tsunami records. Meanwhile, the coastal places in the Visayas region also show tsunami
potential mostly from local generators with a small percent of foreign generators. Furthermore in the Mindanao
region, high tsunami potential is also evident in the mainland area while the small islands located in the
southwest show tsunami potentials by local generators. Tsunamis that are locally generated are more
dangerous than those that are generated by foreign or distant sources because they may reach a nearby shore
in few minutes. There may not be enough time for tsunami warning centers to issue a warning. People living
near the coast with high risk of locally generated tsunami must be alert when there is a reported earthquake in
their area. They must observe unusual ocean changes and listen to loud ocean roars. They must evacuate
immediately when they sense these natural tsunami warning signs.
Map of the Distribution of Volcanoes
Below is the map showing the distribution of volcanoes all over the Philippines. These volcanoes are classified
as active (red), potentially active (orange), and inactive (gray). Places where active and potentially active
volcanoes are prone to hazards of volcanic activities or volcanic eruptions. For example, Mayon Volcano
situated in Albay in the Bicol Region, is known not only for its perfect cone, but also for its volcanic activities. It
has 49 recorded eruptions as of 2013. The areas surrounding the volcano are highly affected by volcanic
hazards. On the contrary, Palawan is not vulnerable to volcanic eruption hazards since there are very few
volcanoes near the area and all of them are inactive.
Activity 2
Your family decided to move to a different place and live there permanently. You know nothing about the safety
of this new place; however, you observed that there is a nearby volcano. Also, there are coastlines several
kilometers from your house. You decided to go to the local government hall to ask about the area, and they
gave you hazard maps. How can you use these maps to confirm the safety of your new home?
What do you think?
Why is it important to understand geological hazard maps?
Key Points
 A geological hazard map is a map indicating the areas that are vulnerable to hazards caused by
earthquakes, volcanic eruptions, and landslides. It helps the public be informed and prepared for the
geological hazard.
PAGE 2 MODULE 3
ST. MARY MAGDALENE COLLEGES OF LAGUNA
Purok 1, Uwisan, Calamba City
SENIOR HIGH SCHOOL
LEARNING MODULE IN EARTH AND LIFE SCIENCE

You must take note of the title, symbols and legend, and source when studying a geological hazard
map.

Geological hazard maps of the Philippines include maps that present the earthquake-prone areas,
tsunami-prone areas, distribution of volcanoes, and earthquake-induced shallow landslides.
Test Question
1. What is a geological hazard map?
a. a map that shows the potential mining areas in different regions of the country
b. a map that shows the areas prone to hazards brought by geological events
c. a map that shows the number of geologists based on specific areas
d. a map that shows the geographic features of an area
2. Which of the following are the points, lines, shapes, and colors used in the map?
a. symbols
b. legends
c. titles
d. sources
3. Which of the following Philippine agencies and institutes produce geological hazard maps?
I. Department of Agriculture
II. Philippine Institute of Volcanology and Seismology
III. Department of Trade and Industry
IV. Department of Environment and Natural Resources
a. I only
b. II only
c. I and II
d. II and IV
Refer to the figure:
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ST. MARY MAGDALENE COLLEGES OF LAGUNA
Purok 1, Uwisan, Calamba City
SENIOR HIGH SCHOOL
LEARNING MODULE IN EARTH AND LIFE SCIENCE
4. Which of the following is true about the red dots? (Refer to Earthquake-Prone Areas)
a. The biggest red dot indicates that the area was hit by a strong earthquake.
b. The smallest red dot indicates that the area was not hit by an earthquake.
c. The smallest red dot indicates that the area was hit by few earthquakes.
d. The biggest red dot indicates that the area was not hit by an earthquake.
Refer to the map below.
5. Which of the following is true about the map of tsunami-prone areas?
a. The colors indicate the potential of a tsunami hazard.
b. The colors magenta and yellow present the frequency of
tsunami occurrences in the past.
c. The Philippines do not have areas that are prone to
tsunamis.
d. The Philippines have areas that experienced tsunamis in
the past. Refer to the map below.
6. Which of the following are true about Albay and Palawan?
PAGE 4 MODULE 3
ST. MARY MAGDALENE COLLEGES OF LAGUNA
Purok 1, Uwisan, Calamba City
SENIOR HIGH SCHOOL
LEARNING MODULE IN EARTH AND LIFE SCIENCE
I. Palawan experiences more volcanic eruptions than Albay.
II. Albay experiences more volcanic eruptions than Palawan.
III. Palawan is near many active volcanoes.
IV. Albay is near active, inactive, and potentially active volcanoes.
a. I and II
b. II and IV
c. II and III
d. I and III Refer to the map below.
7. Which of the following places are prone to earthquake-induced shallow landslides map?
I. Abra
II. Kalinga
III. Ifugao
IV. Palawan
A. I and II B. I, II and III C. III and IV D. II and IV
PAGE 5 MODULE 3
ST. MARY MAGDALENE COLLEGES OF LAGUNA
Purok 1, Uwisan, Calamba City
SENIOR HIGH SCHOOL
LEARNING MODULE IN EARTH AND LIFE SCIENCE
8. Why are locally generated tsunamis more dangerous than those generated by distant sources?
a. They may reach a nearby shore in few minutes, so there may not be enough time for tsunami warning
centers to issue a warning.
b. They are always stronger than foreign generated tsunamis, so they cause widespread destruction and
damage to infrastructures.
c. They carry with them strong typhoons that may cause casualties and damages to houses and buildings.
d. They cause sudden earthquakes that there is not enough time for earthquake warning centers to issue an
alarm or warning.
9. Locate the capital city of the Philippines, Manila. What is the level of landslide hazard in that area?
a. high danger zone
b. low danger zone
c. no present risk
d. no data Refer to the map below.
10. What are the provinces in Visayas that can be directly affected by hazards of volcanic eruptions such as
lahar and pyroclastic flow? (Refer to Distribution of Volcanoes)
I. Negros Occidental
II. Bohol
III. Leyte
IV. Cebu
a. I and II
b. II and III
PAGE 6 MODULE 3
ST. MARY MAGDALENE COLLEGES OF LAGUNA
Purok 1, Uwisan, Calamba City
SENIOR HIGH SCHOOL
LEARNING MODULE IN EARTH AND LIFE SCIENCE
c. I and III
d. II and IV
How do human activities speed up or trigger a landslide?
Landslides may be triggered by natural processes such as heavy rainfall and earthquakes. They can also be
triggered and aggravated by human activities.
Human Activities that Trigger Landslides
Clearcutting is a method done by logging companies to cut down every marketable tree from a selected area
to harvest timber. Deforestation or removal of trees that hold water and topsoil may cause landslides.
Slash-and-burn or kaingin system is a method that cuts down and burns off the existing vegetation. It is a
form of deforestation because the land is converted to other uses.
Mining and quarrying operations use explosives in their blasting techniques to break rocks and gather ore
deposits. They cause land areas to slide due to the vibrations from the blast.
Construction activities such as building of roads and railways may interfere or change the natural drainage of
water. When there is heavy rainfall or flood, water may then move to a different path which may saturate
slopes and cause landslides.
Ways to Lessen the Occurrence of Landslides

Instead of clearcutting, selective cutting can be adopted by logging companies to allow old trees to remain.
This method cuts down mature or inferior kind of trees to encourage the growth of the remaining trees in the
forest.

Do alley-cropping instead of slash-and-burn method. Alley-cropping is a method of simultaneously growing
an agricultural crop with a tree crop, retaining soil fertility.

Plant more trees with strong root structures that hold the soil together.

The government must set mining rules based on the evaluation of slope stability and landslide threat in the
mining areas. Mining companies must follow these rules. In case of disobedience, temporary or permanent
suspension of mining operations must be implemented.

Avoid construction on steep slopes. As this is not entirely possible, evaluation of the area for land development
should be performed by engineers and geologists.

Construct proper drainage away from the slope to control water accumulation and to avoid slope instability.

During construction, do not add an unnecessary weight of fill materials to avoid overloading. Also, check
broken or leaking pipes because oversaturation of soil with water can trigger landslides.
Explore!
PAGE 7 MODULE 3
ST. MARY MAGDALENE COLLEGES OF LAGUNA
Purok 1, Uwisan, Calamba City
SENIOR HIGH SCHOOL
LEARNING MODULE IN EARTH AND LIFE SCIENCE
Imagine that you are the mayor of a town near a mountain. Ground assessment of the area has shown that a
part of the mountain has nickel. A mining company has asked a permit to mine the nickel. What will you do?
Will you grant the permit? Why or why not?
Try it!
Find a picture of a landslide from the Internet. Write something about the picture by answering the questions
below. Be descriptive.
1. What do you think was the reason why the landslide took place?
2. How did the people in that area contribute to the landslide?
What do you think?
What can you do to lessen the occurrence of landslides in your own community?
Key Points

Human activities can increase landslide risks. They include clear-cutting, mining and quarrying, bad agricultural
practices, and construction activities.

Suggestions to lessen landslides include planting more trees, controlling water in the slope, practicing good
agricultural methods, and avoiding construction on steep slopes.
Reference:
https://www.facebook.com/notes/earth-and-life-science/32-understanding-geological-hazardmaps/1819274114975903/
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