8

Science
Quarter 2 - Module 4:
Typhoons

AIRs - LM
Science
Quarter 2 - Module 4: Typhoons
First Edition, 2020

Copyright © 2020
La Union Schools Division
Region I

All rights reserved. No part of this module may be reproduced in any form
without written permission from the copyright owners.

Development Team of the Module

Author: Krystel Mae P. Oredina

Editor: SDO La Union, Learning Resource Quality Assurance Team
Illustrator: Ernesto F. Ramos, Jr., P II

Management Team:

ATTY. Donato D. Balderas, Jr.

Schools Division Superintendent
Vivian Luz S. Pagatpatan, Ph.D
Assistant Schools Division Superintendent
German E. Flora, Ph.D, CID Chief
Virgilio C. Boado, Ph.D, EPS in Charge of LRMS
Rominel S. Sobremonte, Ed.D, EPS in Charge of Science
Michael Jason D. Morales, PDO II
Claire P. Toluyen, Librarian II
 Science
Quarter 2 - Module 4:
Typhoons
 Target

In this module, you will learn how typhoon develops and how it
is affected by landmasses and bodies of water.

To help you understand the module, you will be doing the

following activities in each lesson:

Lesson 1: Understanding Typhoons

• Typhoon concept Map

• Where do I Belong?
• Plotting the PAR
• Am I In or Out?
• Word Hunt

Lesson 2: Factors Affecting Typhoons

• Tracking a Tropical Cyclone

• Tracks of Tropical Cyclone
• To-Go Bag

At the end of this module, you are expected to:

Explain how typhoon develops and how it is affected by

landmasses and bodies of water.

Specifically, the activities will enable you to:

• describe a typhoon;
• identify the parts of a typhoon;
• determine if a tropical cyclone has entered the PAR;
• explain how typhoons are formed;
• identity the factors affecting typhoons;
• exemplify preparedness and awareness when dealing
natural calamities.
What I Know (Pre-test)
Multiple Choices: Read and answer the questions in the best way you can.
Write the letter of the correct answer on the space provided before each number.
_____1. What is the wind speed of a tropical depression?
A. 35-64 kph C. 119-200 kph
B. 65-118 kph D. greater than 200 kph
_____2. What is the wind speed of a tropical storm?
A. 35-64 kph C. 119-200 kph
B. 65-118 kph D. greater than 200 kph
_____3. Which of the following categories of a tropical cyclone with utmost sustained
wind speed of 119-200 kph?
A. Supertyphoon C. Tropical storm
B. Tropical Depression D. Typhoon
_____4. Which of the following has a wind speed of greater than 200 kph?
A. Supertyphoon C. Tropical storm
B. Tropical depression D. Typhoon
_____5. Which of the following is the most intense part of a typhoon?
A. Eye C. Eyewall replacement
B. Eye wall D. Spiral rain bands
_____6. If a typhoon had sustained winds of 185 kph, what is its typhoon signal
category?
A. 1 B. 2 C. 3 D. 4
_____7. Which sector of the Philippine government observes typhoon and updates
on weather forecast?
A. PAG-ASA B. DENR C. DOE D. PHIVOLCS
_____8. All of the following are conditions needed in order for a typhoon to form
EXCEPT one. Which is it?
A. High vertical wind shear C. Atmosphere instability
B. Warm sea surface temperature D. Enough Coriolis force
_____9. How do typhoons develop?
A. When warm air mixes with cold air.
B. When cold air rises above warm air.
C. When winds exceed 200 km per hour but less than 220 km per hour.
D. When a warm ocean air rises into the storm, forming a low-pressure area.
_____10. Which of the following statements is TRUE in the development of typhoons
in an area?
A. Air from the low pressure area flows towards the high pressure area.
B. The warm and moist air rises causing the formation of high pressure area.
C. The warm and moist air rises causing the formation of low pressure area.
D. The sinking air cools down forming clouds in the process of condensation.
_____11. Which is NOT TRUE about the development of a typhoon?
A. Warm ocean water surface temperature must be 26.5 0C or higher.
B. The rising warm air cools down and begins to condense to form clouds.
C. More clouds form and wind rotates faster, pulling more moisture from the
ocean.
D. None of the choices.
_____12. How do bodies of water affect typhoons? Bodies of water __________.
A. fuel and strengthen typhoons
B. slow down the wind speed of typhoons
C. serve as a barrier against strong winds
D. can weaken the impact of typhoons in an area
_____13. Why is the Philippines prone to typhoons? Because Philippines is ______.
 A. surrounded by landmasses
B. located in the Intertropical Convergence Zone
C. located at North Pole which makes the ocean waters warm
D. located near the equator which makes the ocean waters cold
_____14. Why do typhoons die out when they travel over cooler sea surface
temperature? Typhoons die out because __________.
A. there is no enough water vapor to fuel them
B. there is high pressure in the atmosphere
C. there is Coriolis force
D. None of the choices.
_____15. How do landmasses affect typhoons? Landmasses __________.
A. are good source of warm and moist air C. serve as fuel to typhoons
B. supply enough water vapor D. weaken typhoons

LESSON 1
UNDERSTANDING TYPHOONS

Jumpstart
Activity 1: Typhoon Concept Map

Objective: Describe a typhoon.

Directions: Give five words/phrases that can describe a typhoon. Present your
answers in a concept map as shown below.

Figure 1. Typhoon Concept Map

 Discover
What is a typhoon?

Every year the Philippines is hit by typhoons. No part

of the country is spared. All provinces have been visited by a
typhoon at one time or another. In recent years, the
Philippines had been overwhelmed by powerful tropical
cyclones.

According to Philippine Atmospheric, Geophysical,

and Astronomical Services Administration (PAG-ASA), about
20 tropical cyclones enter the Philippine Area of
Responsibility each year.
We all know what typhoon is. Or more accurately, we
know what to expect when a typhoon comes. We get a lot of
rain and strong winds. Now, you may not have noticed it but
the winds in a typhoon move in a certain direction. They go
around a central area. Take a look at figure 2.

The picture shows a supertyphoon as viewed from up

above the Earth. A typhoon looks the same, only smaller. See
the clouds in a spiral arrangement? They are being blown by the winds in a counter-
clockwise direction. In a supertyphoon, the wind speed is greater than 200
kilometers per hour (kph).

If the wind speed is less, from 119 to 200 kph, then it is called a typhoon. If
the wind speed is between 65 and 118 kph, it is called a tropical storm. And when
the wind speed is between 35 to 64 kph, it is a tropical depression.

Tropical depression, tropical storm, typhoon and supertyphoon are categories

of tropical cyclones. In simple terms, a tropical cyclone is a system of
thunderstorms that are moving around a center. As the winds intensify or weaken,
the category is upgraded or downgraded accordingly.

The term typhoon is used only in the northwestern part of the Pacific Ocean.
In the northeastern part of the Pacific Ocean and in the northern part of the Atlantic
Ocean, the equivalent term is hurricane. In the Philippines, we use the term “bagyo”
for all categories of tropical cyclones.

Parts of a Typhoon
Being one of the most vulnerable countries to extreme weather events, we are
also in the frontline when it comes to destructive typhoons. To understand this
natural hazard, let us familiarize ourselves with the different parts of a typhoon.

1. Eye
The eye of a typhoon is an area with the lowest air pressure and its wind speed
is also low. The eye or the center is helpful for weather forecasters and meteorologists
because it serves as the reference point in plotting the typhoon’s location. The
formation of an eye is also used as an indicator of the increasing strength of a tropical
cyclone.
While many people think the eye is the deadliest part of a typhoon, it is the
calmest. In strong tropical cyclones, this area is characterized by light winds and
clear skies.
2. Eye Wall
Surrounding the eye is the eye wall, where the severe weather occurs. It is the
innermost ring of convection near the center of the typhoon, packing the fiercest
rains and most intense winds. When the eye of a tropical cyclone passes over a
certain place, it is the winds at the eyewall that wreak a lot of damage.
The National Oceanic and Atmospheric Administration (NOAA) says this is the
zone where surface winds reach their highest speed, bringing the strongest
thunderstorm activity.
3. Spiral Rain Bands
Spiral rain bands are found outside the eye wall. NOAA defines rain bands as
long bands of clouds and thunderstorms that spiral out of the eye wall. Dense bursts
of rain and winds are often associated with these bands. Also referred to as “buntot
ng bagyo”, rain bands form the outermost fringes of the typhoon structure.

Philippine Area of Responsibility (PAR)

This is the smallest and innermost monitoring domain, whose boundary is
closest to the Philippine Islands. When a weather disturbance enters the PAR, the
weather bureau begins to monitor it. Do you know where the PAR is? Do the following
activities to learn more.

Explore
Activity 2: Where do I Belong?

Objective: Identify and describe the parts of a typhoon.

Directions: Observe the illustration of the typhoon. Label the parts using the given
words inside the box. Then write the description of each part below.

-Eye wall
-Spiral Rain Bands
-Eye

Figure 3. Typhoon. Source: https://www.vox.com/energy-and-environment/2018/10/

24/18018900/super-typhoon-yutu-2018-saipan-tinian-rota

1. Eyewall: ______________________________________________________________
2. Eye: __________________________________________________________________
3. Spiral Rain Bands_____________________________________________________
 Activity 3: Plotting the Philippine Area of Responsibility (PAR)

Objectives: After performing this activity, you should be able to:

1. read a map;
2. determine if a tropical cyclone has entered the PAR based from the given
latitude and longitude.
3. explain what is meant when a typhoon has entered the PAR.
Materials:
map of the Philippines and vicinity and pencil
Procedure: Points Latitude,
1. Plot the given points on the map (Figure 4. Map of the Longitude
Phil. and vicinity). a. 50N, 1150E
2. Connect the plotted points. The region within is the b. 150N, 1150E
PAR. It is the job of PAG-ASA to monitor all tropical c. 210N, 1200E
cyclones that enters this area. d. 250N, 1200E
Guide Questions: e. 250N, 1350E
1. If a typhoon is located at 280N, 1350E, is it within f. 50N, 1350E
the PAR? Yes or No? _____
2. How about if the typhoon is at 230N, 1270E, is it inside the PAR? Yes or No?
_____.

Figure 4. Map of the Phil. and vicinity. Source:https://aldinhrnndz.files.wordpress.com/2015/06/grade-8-laboratory-manual.pdf

 Deepen
Activity 4: Am I In or Out?

Directions: Distinguish if the tropical cyclone is within the PAR or not based from
the map of the Philippines and vicinity. Write IN if the cyclone is inside
the PAR and OUT if it’s not.

______1.

______2.

______3.

______4.

______5.

______6.

______7.

______8.

______9.

_____10.

Figure 5. Map of the Phil. and vicinity

Source:https://aldinhrnndz.files.wordpress.com/2015/06/grade-8-laboratory-manual.pdf
 Gauge
Activity : Word Hunt

Directions: Find and encircle the words in the puzzle below. Look for them in all
directions including backwards and diagonal then use the encircled
words to answer the statements that follow.

_______1. These are longs bands of clouds and thunderstorms that spiral out of
the eye wall.
_______2. It is the calmest part of the typhoon.
_______3. Its wind speed is greater than 200 kph.
_______4. It is a system of thunderstorms that are moving around a center.
_______5. Its wind speed is between 35 and 64 kph.
_______6. This part of typhoon is where severe weather occurs.
_______7. It is the equivalent term for typhoon when it is in the northeastern part
of the Pacific Ocean.
_______8. Its wind speed is between 65 and 118 kph.
_______9. Its wind speed is from 119 to 200 kph.
_______10. This agency provides typhoon warnings and public weather forecasts.
 LESSON 2 FORMATION OF TYPHOONS

Jumpstart

Tropical cyclones need water vapor in order to form. Which is better source
of water vapor, landmasses or oceans? The answer is obvious. But not all parts of
the ocean can provide water vapor. Where do you think would evaporation be
greatest, near the equator or away from the equator?

Thus tropical cyclones require warm ocean waters to be able to develop.

According to scientists, the temperature of ocean water must be 26.5 0C or greater.
Given this information, do you think typhoons can form in latitudes away from the
equator? Why or why not?

Discover
Who could forget the terrible flood brought by Tropical Storm Ondoy in
2009? Or the people swept out to sea during Tropical Storm Sendong in 2011? Or
the poor community of New Bataan buried in mud spawned by Typhoon Pablo in
2012? Or the deadliest Supertypoon Yolanda that hit Tacloban City in 2013? You
might be asking how these typhoons develop.

How are typhoons formed and developed?

Typhoons are powerhouse weather events that suck heat from tropical
waters to fuel their fury. These violent storms form over the ocean, often beginning
as a tropical wave—a low pressure area (LPA) that moves through the moisture-rich
tropics, possibly enhancing shower and thunderstorm activity.
As this weather system moves westward across the tropics, warm ocean
air rises into the storm, forming an area of low pressure underneath. This causes
more air to rush in. The air then rises and cools, forming clouds and thunderstorms.
Up in the clouds, water condenses and forms droplets, releasing even more heat to
power the storm. When wind speeds within such a storm reach 119 kph, it’s
classified as a typhoon.
Tropical cyclones can only form over oceans of the world except in the
South Atlantic Ocean and in the South Eastern Pacific where a tropical cyclone could
never be formed due to the cooler sea surface temperature and higher vertical wind
shears. They develop at latitudes usually greater than 5° from the equator. They
reach their greatest intensity while located over warm tropical water. As soon as they
move inland, they begin to weaken, but often not before they have caused great
destruction.
 Tropical cyclones generally move in a northwest direction because there
are large-scale winds that push the tropical cyclones in that direction. This is why
Southern part of the Philippines is often untouched by tropical cyclones.

Figure 6. Formation of a Typhoon

Source:https://www.theglobeandmail.com/news/world/explainer-how-are-typhoons-formed/article15373372/

What conditions favor the formation of typhoons?

The following are six requirements for the formation of a typhoon:
1. sufficiently warm sea surface temperatures (26.50C or greater);
2. atmospheric instability;
3. high humidity in the lower to middle levels of the troposphere;
4. enough Coriolis force to develop a low pressure center;
5. low vertical wind shear and
6. pre-existing low level focus

Factors Affecting Typhoons

A. Landmasses
• Landmasses weaken typhoons. Typhoons need a large amount of
water vapor from a vast area of water, but since landmasses have
relatively low amount of water, typhoons landing on landmasses
usually become weaker.
• Mountain ranges can impede or slow down the wind speed and
strength of typhoons. Mountains serve as a barrier against strong
winds and heavy precipitation.
• Orthographic lifting can weaken the impact of a typhoon in an area.
It refers to the flow of air from oceans to mountains causing
orthographic precipitation. This causes areas at the seaside to
become wetter and those in the leeside to become drier and less
prone to typhoons.
B. Bodies of Water
• Bodies of water fuel and strengthen typhoons. It provides the water
necessary for evaporation to produce warm, moist air that fuels a
typhoon. This is why all typhoons originates from large bodies of
water.
• These bodies of water determine the humidity and temperature
which are important in the formation of typhoons.

Why is the Philippines prone to typhoons?

1. It is surrounded by large bodies of water.
2. It is located just above the equator which makes the ocean waters
warm.
 3. It is located in the Intertropical Convergence Zone (ITCZ). It is where
trade winds meet which can cause storms and other weather
disturbances.

Public Storm Warning Signals (PSWS)

When a tropical cyclone enters the PAR and it is on its way toward land,
warning signals are issued. The following signals are used by PAG-ASA to warn
people about approaching weather disturbance. Do you know what the signals
mean?

PSWS What it means What may happen What to do

1 -Winds of 30-60 kph -Twigs and branches of -Watch out for big
may be expected in small trees are broken waves
at least 36 hours or -Some bananas are tilted -Listen to severe
irregular rains may -Some houses of very light weather bulletin
be expected materials partially issued by PAG-ASA
unroofed
2 -Winds of greater -Some old galvanized iron -Avoid riding in a
than 60-100 kph roof may be peeled off small seacraft
may be expected in -Few big trees may be -Postpone outdoor
at least 24 hours uprooted activities of children
-Rice and corn may be
adversely affected
3 -Winds of greater -Many coconut trees may -Seek shelter in strong
than 100-185 kph be broken buildings
may be expected in -Rice and corn crops -Evacuate from low-
at least 18 hours suffer heavy losses lying areas
-Widespread disruption of -Stay away from
electrical power coasts and river banks
4 -A very intense -Coconut plantation may -Evacuation to safer
typhoon will affect suffer extensive damage shelters should have
locality -Many large trees maybe been completed by
-Very strong winds uprooted now
of more than 185 -Many buildings maybe -The locality is very
kph may be expected severely damaged likely to be hit directly
in at least 12 hours -Damage to communities by the eye of the
maybe heavy typhoon

To be fully prepared for tropical cyclones, you should also put together an
emergency kit. You must learn how to rely on yourself. In times of disaster, it may
take a while before help arrives.
 Explore
Activity 1: Tracking a Tropical Cyclone

Objective: Determine if your location is in the path of a tropical cyclone, given the
latitude and longitude position.
Materials:
map with the PAR (from Activity 3, Lesson 1); tracking data; pencil
Procedure:
1. Using the data in Table 1, plot the day-to-day location of the tropical
cyclone Sendong on the map showing the Philippine Area of
Responsibility.
2. Mark each location with a dot.
3. Connect the dots to track the cyclone from December 13 to 19, 2011.

Table 1. Tropical Storm Sendong (International name: Washi)

Date Time Latitude (0N) Longitude (0E)
December 13 6 am 6.00 145.10
12 pm 6.40 143.30
6 pm 6.00 141.70
12 am 5.90 140.60
December 14 6 am 6.20 139.00
12 pm 6.70 137.70
6 pm 7.00 136.30
12 am 7.20 134.30
December 15 6 am 7.60 132.30
12 pm 7.70 130.80
6 pm 7.50 129.10
12 am 7.40 128.10
December 16 6 am 8.00 126.80
12 pm 8.40 125.50
6 pm 8.50 123.80
12 am 9.10 122.40
December 17 6 am 9.20 121.20
12 pm 9.60 120.40
6 pm 10.20 119.00
12 am 10.90 117.60
December 18 6 am 10.30 115.70
12 pm 9.90 114.60
6 pm 9.60 113.90
12 am 9.10 112.90
December 19 6 am 9.70 111.90
12 pm 10.50 110.70
Tracking data are from http://weather.unisys.com/hurricane/w_pacific/2011H/index.php

Sendong started out in the Pacific as an area of low pressure area. Since it
was just a low-pressure are, it was not given a name. Then it intensified into a
tropical depression. Again it was not yet given a name because it was still outside
the PAR.
 When it finally entered the PAR, it had already strengthened into a tropical
storm. Since it was within the PAR by then, PAG-ASA gave it a name--Sendong
(Washi).
Guide Questions:
1. Where did Typhoon Sendong form? ________________________________________
2. When did Typhoon Sendong enter the PAR? ________________________________
3. When did Typhoon Sendong leave the PAR? ________________________________
4. In what direction did Typhoon Sendong move? _____________________________

Deepen
Activity 2: Tracks of Tropical Cyclones
Directions: Shown below are the tracks (paths) of four tropical cyclones that entered
the PAR in the past years. The tracks were plotted by PAG-ASA. Study the
maps then answer the following questions.

Figure 7. Tracks of selected tropical cyclone (Source: LM, K-12 Gr 8 Science)

Questions:
1. Where did the tropical cyclone form? On land or in the ocean? ______________
2. What can you say about the temperature of the bodies of water in the
vicinity of the Philippines? Is the water warm or cold? ______________________
3. In what direction did the tropical cyclones move? __________________________
4. Which part of the Philippines was hit by the four tropical cyclones? _________
5. In the case of Agaton, Yoyong and Huaning, where did they die out? Near
land or in the middle of the ocean? Why did they die out there?
___________________________________________________________________________
Activity 3: To-Go Bag

Directions: You heard in the news that a supertyphoon might hit your location in the
next few days. Your location is prone to floods and landslides that’s why
you are advised to evacuate. If you are going to put things in your bag,
what are these? (Enumerate at least 10)

Source:
https://www.pinterest.ph/pin/201958364517793796/?nic_v2=1aXMpgBix
 Gauge

Part 1. Directions: Read the weather forecast inside the box. Based from the weather
forecast, answer the questions below.

MANILA, Philippines – Signal No. 4 was raised in Cagayan and the

northern part of Isabela late Friday afternoon, September 14, as Typhoon
Ompong (Mangkhut) slightly accelerated and moved closer to the two
provinces.
In a bulletin issued 5 pm on Friday, the Philippine Atmospheric,
Geophysical, and Astronomical Services Administration (PAGASA) said
Ompong is already 340 kilometers east northeast of Casiguran, Aurora,
moving northwest at a slightly faster 30 kilometers per hour (km/h) from the
previous 25 km/h.
The typhoon continues to have maximum winds of 205 km/h and
gustiness of up to 255 km/h. Even if PAGASA does not yet classify Ompong
as a super typhoon, it remains to be a powerful tropical cyclone with a huge
diameter of 900 kilometers.
Ompong is expected to make landfall in the Cagayan-Isabela area on
Saturday, September 15, possibly between 1 am and 3 am. Stormy weather
is expected in areas under Signal Nos. 2, 3, and 4, while there will be
occasional rains and gusty winds in areas under Signal No. 1. The National
Disaster Risk Reduction and Management Council estimated that at least 5.2
million people are in the path of the typhoon.
Storm surge-prone areas in Cagayan, Isabela, Ilocos Norte, and Ilocos
Sur may also experience storm surges up to 6 meters high – dangerous and
potentially damaging.
Based on its latest forecast track, Ompong might leave the Philippine
Area of Responsibility (PAR) on Saturday afternoon or evening. This is earlier
than initially projected since Ompong speed up, but the time of exit could still
change if it slows down.

_____1. Where is the location of tropical cyclone “Ompong”?

A. East northeast of Cagayan C. East northeast of Casiguran, Aurora
B. East northeast of Isabela D. East northeast of the Philippines
_____2. In what direction does tropical cyclone “Ompong” move?
A. Northeast direction C. West-Northeast direction
B. Northwest direction D. West-Northwest direction
_____3. Where is tropical cyclone “Ompong” expected to move by Friday, September
14, 2018?
A. Cagayan and Isabela C. Isabela and Aurora
B. Cagayan and Aurora D. Ilocos Norte and Ilocos Sur
_____4. When is tropical cyclone “Ompong” expected to leave the Philippine Area of
Responsibility?
A. Saturday morning C. Saturday afternoon or evening
B. Saturday noon D. Sunday afternoon or evening
_____5. When is “Ompong” expected to make its landfall in the Cagayan-Isabela area?
A. Saturday, possibly between 12 am to 1 am.
B. September 15, possibly between 1 am to 3 am.
C. September 15, possibly between 2 am to 3 am.
D. Saturday possibly between 3 am to 4 am.
_____6. What particular areas will experience storm-surges up to 6 meters-high?
A. Cagayan, Isabela, Ilocos Norte C. Isabela, La Union, Pangasinan
B. Cagayan, Ilocos Norte, La Union. D. La Union, Pangasinan, Tarlac
_____7. What is the maximum wind of the tropical cyclone when it hits Cagayan and
Isabela?
A. 25 km/h B. 30 km/h C. 205 km/h D. 300 km/h

Part 2. True or False

Directions: Write TRUE if the statement is correct otherwise, write FALSE.

_____8. If the PSWS is #3, the winds of 30-60 kph may be expected in at least 36
hours.
_____9. Very strong winds of more than 185 kph may be expected in atleast 12 hours
if it is PSWS #4.
_____10. Tropical cyclones can be formed in the South Atlantic Ocean and in the
South Eastern Pacific since the water is cold.
_____11. A typhoon starts to form when a warm ocean air rises into the storm,
forming a low-pressure area.
_____12. Philippines is prone to typhoons because it is located in the Intertropical
Convergence Zone (ITCZ).
_____13. Mountain ranges can impede or slow down the wind speed of a typhoon.
_____14. The required temperature of an ocean water must be 23 0C or lesser in order
for a typhoon to form.
_____15. Bodies of water fuel and strengthen typhoons.

What I Have Learned (Post-test)

Multiple Choices: Read and answer the questions in the best way you can.
Write the letter of the correct answer on the space provided before each number.

_____1. Which of the following classification of tropical cyclone with utmost

sustained wind speed of 119-200 kph?
C. Supertyphoon C. Tropical storm
D. Tropical Depression D. Typhoon

_____2. Which of the following has a wind speed of greater than 200 kph?
C. Supertyphoon C. Tropical storm
D. Tropical depression D. Typhoon
_____3. If a typhoon had sustained winds of 60-100 kph, what is its typhoon signal
category?
B. 1 B. 2 C. 3 D. 4
_____4. All of the following are conditions needed in order for a typhoon to form
EXCEPT one. Which is it?
C. High vertical wind shear C. Atmosphere instability
D. Warm sea surface temperature D. Enough Coriolis force
_____5. How do landmasses affect typhoons? Landmasses __________.
A. are good source of warm and moist air C. serve as fuel to typhoons
B. supply enough water vapor D. weaken typhoons
_____6. Why is the Philippines prone to typhoons? Because Philippines is ________.
A. surrounded by landmasses
B. located in the Intertropical Convergence Zone
C. located at North Pole which makes the ocean waters warm
D. located near the equator which makes the ocean waters cold
_____7. Which of the following explains how typhoons develop?
A. When warm air mixes with cold air.
B. When cold air rises above warm air.
C. When winds exceed 200 km per hour but less than 220 km per hour.
D. When a warm ocean air rises into the storm, forming a low-pressure area.
_____8. Which of the following statements is TRUE in the development of typhoons
in an area?
A. Air from the low pressure area flows towards the high pressure area.
B. The warm and moist air rises causing the formation of high pressure area.
C. The warm and moist air rises causing the formation of low pressure area.
D. The sinking air cools down forming clouds in the process of condensation.
_____9. Why do typhoons die out when they travel over cooler sea surface
temperature? Typhoons die out because __________.
A. there is no enough water vapor to fuel them
B. there is high pressure in the atmosphere
C. there is Coriolis force
D. None of the choices.
_____10. How do bodies of water affect typhoons? Bodies of water __________.
A. fuel and strengthen typhoons
B. impede the wind speed of typhoons
C. serve as a barrier against strong winds
D. can weaken the impact of typhoons in an area

For question 11-15, refer to the figures below.

_____11. In what direction did the typhoons move? The typhoons move in_________.
A. north direction. C. westward direction.
B. northwest direction. D. northeast direction.
_____12. Which part of the country was hit by the four typhoons?
A. Eastern Luzon C. Extreme Luzon
B. Northern Luzon D. Western Luzon
_____13. Where did the tropical cyclones form?
A. On the land C. In the ocean
B. In Mindanao D. In the Philippines
_____14. In the case of Agaton, Yoyong, and Huaning, where did they die out?
A. The three tropical cyclones died out naturally.
B. The three tropical cyclones died out near the land.
C. The tropical cyclones died out near Northern Luzon.
D. The tropical cyclones died out in the middle of the ocean.
_____15. Which among the four typhoons developed within the Philippine Area of
Responsibility?
A. Agaton & Yoyong C. Harurot & Yoyong
B. Agaton & Huaning D. Yoyong & Huaning
Key Answer
References:

Books:

• Learner’s Module, K-12 Grade 8 Science

• Teacher’s Module, K-12 Grade 8 Science

Links:

• https://panahon.tv/beta/v2/web/blog/2016/11/anatomy-of-a-typhoon/

• http://bagong.pagasa.dost.gov.ph/learning-tools/philippine-area-of-
responsibility

• https://aldinhrnndz.files.wordpress.com/2015/06/grade-8-laboratory-
manual.pdf

• https://oceanservice.noaa.gov/facts/how-hurricanes-form.html

• http://bagong.pagasa.dost.gov.ph/information/about-tropical-cyclone

• https://www.pmfias.com/tropical-cyclones-favorable-conditions-tropical-
cyclone-formation/