Grade 9 Science Quarter 3 Lesson

1. Activity: Volcano Crossword
Directions: Complete the crossword puzzle for the unlocking of
terms. Use the word bank below.

5. TARGET GOALS
1. identify the types of volcanos according to shape and volcanic
eruption
2. perform a hands-on activity that determine the factors affecting the
viscosity of magma
3. discuss the importance of awareness about volcanic hazards
before and during a volcanic eruption.

7. Volcanic Eruption
• Happens when magma,
gases and other molten
materials are
discharged from the
opening of the volcano.

8. Types of Volcano According to SHAPE
• Are formed by the pile up of
non-viscous lava that oozes
out from the volcano.
• Since lava can flow freely, a
broad, slightly domed structure
is formed that resembles like a
warrior’s shield.
EIHLDS LOONVAC
SHIELD VOLCANO
MAUNA LOA IN HAWAII

9. Types of Volcano According to SHAPE
• Are formed due to alternating
solidification of both lava and
pyroclastic deposits which
makes it nearly a perfect sloped
structure.
• Pyroclastic flows occur when
these volcanoes erupt.
IEPMOOCST NLOVOCA
COMPOSITE VOLCANO
MT. MAYON IN THE PHILIPPINES

10. Types of Volcano According to SHAPE
• Are formed from alternating
ejected lava fragments and
ash.
• They have a steep slope, wide
crater on top and are the most
abundant of the three major
volcano types.
REDNIC SOCEN
CINDER CONES
MT. PARICUTIN IN MEXICO

11. MT. SAINT HELENS IN WASHINGTON
CINDER CONE VOLCANO

12. MAUNA KEA IN HAWAII
SHIELD VOLCANO

13. MT. FUJI IN JAPAN
COMPOSITE VOLCANO

14. Types of VOLCANIC ERUPTION
• is a steam-blast small
eruption as hot rocks
come in contact with
water
PHREATIC OR
HYDROTHERMAL

15. Types of VOLCANIC ERUPTION
• a violent & explosive
eruption resulting from
the interaction between
magma and water
PHREATOMAGMATIC

16. Types of VOLCANIC ERUPTION
• least violent type of
explosive eruption
characterized by a
fountain of lava
STROMBOLIAN

17. Types of VOLCANIC ERUPTION
• small to moderate explosive
eruptions characterized by
tall eruption that reach up
to 20 km high with
pyroclastic flow and ashfall
tephra
VULCANIAN

18. Types of VOLCANIC ERUPTION
• excessively explosive
type of eruption of gas
and pyroclastics
PLINIAN

19. KRAKATAU VOLCANO IN INDONESIA
VULCANIAN ERUPTION

20. MT. PINATUBO IN THE PHILIPPINES
PLINIAN ERUPTION

21. TAAL VOLCANO IN THE PHILIPPINES
PHREATIC ERUPTION

22. YASUR VOLCANO IN TANNA ISLAND
STROMBOLIAN ERUPTION

23. SOUFRIERE HILLS VOLCANO IN MONTSERRAT
PHREATOMAGMATIC ERUPTION

24. Factors that Affect Viscosity of Magma
VISCOSITY - the property of the material’s resistance to flow. The more
viscous and thicker the magma is, the greater is its resistance to flow.
1. Temperature : temperature viscosity
2. Chemical Composition : silica content viscosity
3. Amount of Dissolved Gases it Contain : amount of gas viscosity

25. Activity: Fact or Bluff
Directions: The following statements are facts and bluffs about volcanos.
All female students will stand if the statement is a fact and all
male students will stand if the statement is a bluff.
1. All volcanoes are cone-shaped.
2. Volcanoes are found only on land.
3. A volcano has an opening at the top (or in some case, on the sides).
4. Hot thick cloud of gas, molten rocks and ash come out of a volcano’s
opening.
5. All volcanoes erupt violently.

26. Activity: Fact or Bluff
6. A volcano is not dangerous if it does not produce lava.
7. Volcanoes are described according to their shape and type of
eruption.
8. A volcanic eruption happens when there is an earthquake
beneath the earth’s crust.
9. The pressure of dissolved gas building up in the magma
causes a volcanic eruption.
10. Strombolian is the same as Plinian volcanic eruption.

27. ASSESSMENT
Directions: Read the statements carefully and choose the letter of your
answer.
1. How do you describe a volcano?
a. A cone- shaped mountain formed by erupting lava, ash and gases.
b. A landform which has a summit but without a crater.
c. A mountain created by the faulting and folding of the Earth’s crust.
d. The movement of the Earth’s crust when plate boundaries move.

28. ASSESSMENT
2. The following are factors affecting the viscosity of the magma
EXCEPT
a. temperature of magma
b. size of the volcano’s crater
c. chemical composition of magma
d. amount of dissolved gases contained in the magma

29. ASSESSMENT
3. Mt. Mayon is an example of a ____________ volcano because
_____________.
a. cinder cone; it is formed exclusively of pyroclasts
b. composite; it is composed of alternating layers of pyroclastic
fragments and solidified lava flows
c. shield; it is constructed of solidified lava flows
d. Caldera; it was created when the summit was blown off by
exploding gases

30. ASSESSMENT
4. Mount Pinatubo erupted last April 2, 1991. What kind of
volcanic eruption was Mt. Pinatubo?
a. vulcanian
b. phreatomagmatic
c. strombolian
d. plinian

31. ASSESSMENT
5. What is the meaning of PHIVOLCS? The national
institution dedicated to provide information on the
activities of volcanoes, earthquakes, and tsunamis,
as well as other related phenomenon.