The document discusses the formation, classification, and characteristics of volcanoes in the Philippines, which are part of the Pacific Ring of Fire. It categorizes volcanoes into active, dormant, and extinct and further classifies them by their shapes (e.g., stratovolcano, shield volcano, lava dome, caldera, and cinder cones). Additionally, it outlines the primary and secondary effects of volcanic eruptions and the benefits these geological features bring to the environment and economy.

1. Volcanoes in the
Philippines
Presented by: ADELINE P. DELA CRUZ
For the course Elements in Geography

2. A volcano is a mountain or hill, typically
conical in shape, having a vent or opening
through which lava, rock fragments, ash,
hot vapor, and gases are ejected by means
of eruption or explosion.

3. The magma that reaches the surface of the Earth
is called lava. The magma flows out through a
main vent, and in some cases, through several
secondary vents. A volcanic crater is formed when
an eruption blows off the top of the volcano.

4. HOW ARE VOLCANOES FORMED?
When tectonic plates collide and go through the process of
subduction, it sets the foundation for a volcano. The overlapping of
the tectonic plates causes the magma to break through the crust,
which is the cause of a volcanoes’ birth.
When temperature and pressure rises, the rock melts and moves
through the surface and crust, and releases gases and magma, then
volcanic eruption occurs.
A volcano forms when magma from under the Earth’s crust,
forces its way up to the surface where it erupts in a flow of lava and
volcanic ash.

5. Volcanoes occur along constructive and destructive
plate boundaries. A major area in the Pacific
Ocean basin which is a hot spot for earthquakes
and volcanoes is popularly referred to as the Ring
of Fire. It consists of a series of volcanic belts,
plate movements and seismic activity. The
Philippines this Ring of Fire is considered to be
one of the most tectonically active place on Earth.

6. Volcanoes are classified as active, dormant or extinct.
1. Active volcano are those which erupts frequently or have
recent history of eruptions.
2. Dormant volcanoes have not erupted for a very long
time, but may erupt at a future time.
3. Extinct volcanoes are not expected to erupt in the
future.
CLASSIFYING VOLCANOES ACCORDING TO
ACTIVITY:

7. There are 5 broad types of
volcanoes:
1. stratovolcano;
2. shield volcano;
3. lava domes;
4. Caldera; and
5. cinder cones.
TYPES OF VOLCANOES ACCORDING TO SHAPE:

8. 1. Stratovolcano:
They have relatively steep sides and are more
cone-shaped than shield volcanoes. They are formed from
viscous, sticky lava that does not flow easily. The lava
therefore builds up around the vent forming a volcano with
steep sides. Stratovolcanoes are more likely to produce
explosive eruptions due to gas building up in the viscous
magma. (Example: almost all volcanoes in the Phils.)
TYPES OF VOLCANOES ACCORDING TO SHAPE:

9. 2. Shield Volcano:
The name derives from the flat, shield-like shape of the volcanic
mountain. A shield volcano is flat with gentle slopes. Where a volcano
produces low viscosity, runny lava, it spreads far from the source and forms
a volcano with gentle slopes: a shield volcano. Most shield volcanoes are
formed from basaltic lava flows.
(Example: The Taal Volcano in the Philippines is considered as a shield
volcano because of its distinct shape and its nonviolent eruptions. It also
has a caldera system that is consistent with shield volcanoes.)
TYPES OF VOLCANOES ACCORDING TO SHAPE:

10. 3. Lava Dome:
A lava dome forms when the lava that flows out for long
distances. Lava collects around the opening and forms a
dome-shaped structure. As viscous lava is not very fluid, it
cannot flow away from the vent easily when it is extruded.
Instead it piles up on top of the vent forming a large,
dome-shaped mass of material. (Example: Mt. Musuan,
Maramag, Bukidnon, Northern Mindanao, Phils.)
TYPES OF VOLCANOES ACCORDING TO SHAPE:

11. 4. Calderas:
Magma is stored beneath a volcano in a magma chamber. When a very
large, explosive eruption occurs that empties the magma chamber, the roof
of the magma chamber can collapse to form a depression or bowl with very
steep walls on the surface. These are calderas and can be tens of miles
across.
Calderas can also be formed during an eruption that removes the
summit of a single stratovolcano. The top can literally be blown off!
Example: Taal Volcano in Batangas, Philippines.
TYPES OF VOLCANOES ACCORDING TO SHAPE:

12. 5. Cinder Cones:
Cinder cones are the simplest type of volcano. They are built from the
particles and blobs of congealed lava ejected from a single event. As the
gas-charged lava is blown violently into the air, it breaks into small
fragments that solidify and fall as cinders around the vent to form a
circular or oval cone. A cinder cone is best described as a short steep
volcano that ejects pyroclastic material from a central vent. Its structure
is simple, having steep sides around a single vent with occasional
low-viscosity lava flows around its base after the initial explosive eruption.
Example: Smith Volcano located in Calayan, Cagayan Valley, Phils.
TYPES OF VOLCANOES ACCORDING TO SHAPE:

13. A. In Southeast Asia:
In 1883, Krakatoa erupted. It released 200
megatons of energy, which is equivalent to
15,000 nuclear bombs. It was the loudest
sound ever reported in history.
EXAMPLE OF STRONG VOLCANIC ERUPTIONS

14. A. In Southeast Asia:
In the Philippines, Mount Pinatubo of
Luzon Volcanic Arc erupted in 1991. It was
the second-largest volcanic eruption of the
20th century, behind only to the 1912
eruption of Novarupta in Alaska.
EXAMPLE OF STRONG VOLCANIC ERUPTIONS

15. The Philippines, being located along the Pacific
Ring of Fire, has 100 volcanoes according to the
Smithsonian Institution’s Global Volcanism
Program (GVP), 23 of which are categorized as
active volcanoes. The next slides shall present
the 23 Active Volcanoes in the Philippines.
THE PHILIPPINES 23 ACTIVE VOLCANOES:

16. 23 ACTIVE
VOLCANOES
IN THE PHILIPPINES
*Arranged in alphabetical order

17. Elevation: 843 m. (2,766 ft.)
No. of Eruptions: 4
Last Eruption: 1924
Also known as: Mt. Pangasun
Mountain type: Stratovolcano
Location: Babuyan Islands,
City/Municipality: Calayan
Province: Cagayan
Region: Cagayan Valley Region,
Northern Luzon
1. Mt. Babuyan Claro

18. Elevation: 2,170 m. (7,120 ft.)
No. of Eruptions: 3
Last Eruption: 1909
Also spelled as: Banahao, Banajao
Considered as holy mountain, is popular
among pilgrims and mountain climbers.
Mountain type: Stratovolcano complex
Municipalities: Lucban, Majayjay,
Nagcarlan, Rizal, San Pablo, Sariaya, and
Tayabas.
Province: Laguna and Quezon
Region: CALABARZON
2. Mt. Banahaw

19. Elevation: 1,340 m. (4,400 ft.)
No. of Eruptions: 1
Last Eruption: Sept. 26, 1939
Mountain Type:
Stratovolcano Complex
Location: Biliran Island,
Biliran Province, Leyte
Eastern Visayas Region
Note: This volcano caused
the formation of Biliran
Island.
3. Mt. Biliran

20. Elevation: 620 m. (2,034 ft.)
No. of Eruptions: 2
Last Eruption: Jan. 4, 1641
Location: Jolo Island
Province: Sulu
Region: BARMM
Note: A tsunami occurred
in 1897, probably caused a
local submarine eruption
by this volcano.
4. Mt.Bud Dajo

21. Elevation: 1,565 m. (5,135 ft.)
No. of Eruptions: 17
Last Eruption: June 12, 2022
Mt. Type: Stratovolcano
Municipality: Bulusan,
Barcelona, Casiguran, Gubat,
Irosin, Juban
Province: Sorsogon
Region: Bicol
5. Mt. Bulusan

22. Elevation: 945 m. (3,100 ft.)
No. of Eruptions: 1820 +-30
Mt. Type: Stratovolcano
Location: Southern Leyte
Region: Region VIII
*Cabalian Lake (Lake Danao) is a
500m wide crater lake that
occupies the summit crater of the
volcano.
**Mainit Hot Spring in the
municipality of Anahawan, So.
Leyte has a temperature of 63.4 to
63.9 degrees Centigrade.
6. Mt. Cabalian

23. Elevation: 1,133 m. (3,717 ft.)
No. of Eruptions: 2
Last Eruption: October 1907
Mt. type: Stratovolcano
Municipality: Gonzaga
Province: Cagayan
Region: Cagayan Valley,
Northern Luzon
Parent Range: Sierra Madre
7. Mt. Cagua

24. Elevation: 712 m. (2,336 ft.)
No. of Eruptions: 1
Last Eruption: 1857
Also known as: Camiguin Norte to
distinguish it from Camiguin Sur
which is in Mindanao.
Mt. type: Stratovolcano
Location: Camiguin Island,
Calayan, Cagayan
8. Camiguin
Babuyanes

25. Elevation: 228 m. (748 ft.)
Last Eruption: Jan. 6-9, 1978
No. of Eruptions: 8
1) 1773
2) 1856
3) 1857
4) 1900
5) 1952
6) 1953
7) 1969
8) 1978
Mt. type: Volcanic Islands
Province: Cagayan
Region: Cagayan Valley
9. Mt. Didicas

26. Elevation: 1,332 m. (4,370 ft.)
No. of Eruptions: 5
Last Eruption: Sept. 1948 to
July 1953
Mt. Type: Stratovolcano
Province: Camiguin
Region: Northern Mindanao
It has 6 hot springs: Ardent
Spring, Tangob, Bugong,
Tagdo, Naasag, and Kiyab.
It has 3 craters: Kanangkaan
crater, Itum Crater, Ilihan
Crater.
10.Mt. Hibok-hibok

27. Elevation: 1,009 m. (3,310 ft.)
No. of Eruptions: 1
Last Eruption: 1454
Mt. Type: Stratovolcano
Province: Batanes
Region: Cagayan Valley
It is a sacred mountain of the
Ivatan people.
Mythology: 2 contrasting
tales…
11. Mt. Iraya

28. Elevation: 1,196 m. (3,924 ft.)
No. of Eruptions: 2
Last Eruption: Jan. 4, 1642
Also known as Mt. Asog
Mt. Type: Stratovolcano
City/Municipality: Buhi, Iriga
Province: Camarines Sur
Region: Bicol
12. Mt. Iriga

29. Elevation: 2,465 m. (8,087 ft.)
No. of Eruptions: 26
Last Eruption: June 3, 2024
Mt. Type: Stratovolcano
City/Municipality: Canlaon, La
Carlota, La Castellana, Murcia,
San Carlos
Provinces: Negros Oriental,
Negros Occidental
Region: Negros Island Region
Etymology: “Kanlaon” means
“place of Laon,” a precolonial
goddess of creation, agriculture
and justice. “Laon” also ancient.
13. Mt.Kanlaon

30. Elevation: 1,190 m. (3,900 ft.)
No. of Eruptions: 0
Last Eruption: 120 A.D.
Mt. Type: Stratovolcano
City/municipality: Mabini,
Marco
Province: Davao de Oro
Region: Davao, Mindanao
14. Leonard
Kniaseff

31. Elevation: 1,940 m. (6,360 ft.)
No. of Eruptions: 10
Last Eruption: March 1882
Mt. Type: Stratovolcano
Locally, it is called Palaw a
Magatoring.
City/municipality: Butig
Province: Lanao del Sur
Region: BARMM
15.Mt.Makaturing

32. Elevation: 2,286 m. (7,500 ft.)
No. of Eruptions: 1
Last Eruption: March 7, 1911
Mt. Type: Stratovolcano
City/Municipality: Tupi
Province: South Cotabato
Region: Soccsksargen
16.Mt. Matutum

33. Elevation: 2,463 m. (8,081 ft.)
No. of Eruptions: 49
Last Eruption: Sept. 2024
Also Mayon Volcano, famous for
its perfect cone shape, it is the
most active volcano in the Phils.
It is the main landmark of Albay
and the whole Bicol Region.
Mt. type: Stratovolcano
Cities/Municipalities: Camalig,
Daraga, Guinobatan, Legazpi,
Ligao, Malilipot, Santo Domingo,
Tabaco.
Province: Albay
Region: Bicol
17. Mt. Mayon

34. Elevation: 646 m. (2,119 ft.)
No. of Eruptions: 2
Last Eruption: 1887
Also known as Musuan
Peak, or Mt. Calayan
Mt. Type: Lava Dome
City/Municipality: Maramag
Province: Bukidnon
Region: Northern Mindanao
18. Mt. Musuan

35. Elevation: 1,824 m. (5,984 ft.)
No. of Eruptions: 1
Last Eruption: Jan. 4, 1640
Mt. Type: Stratovolcano
Municipality: T’boli
Province: South Cotabato
Region: Soccsksargen
*Now Mt. Melibengoy
19.Parker Volcano

36. Elevation: 1,486 m. ( 4,875 ft.)
No. of Eruptions: 3
Last Eruption: Nov. 30, 2021
Mt. Type: Stratovolcano
Provinces: Pampanga,
Tarlac, Zambales
Region: Central Luzon
Parent Range: Zambales
Mountain Range
*Known for its VEI-6
eruption on June 6, 1991.
20. Mt. Pinatubo

37. Elevation: 2,815 m. (9,236 ft.)
No. of Eruptions: 8
Last Eruption: July 1916
Mt. Type: Stratovolcano
Province: Lanao del Sur
Regions: BARRM, Soccsksargen,
Lanao del Sur
Parent Range: Piapayungan Range
Also known as: Mt. Piapayungan
21. Mt. Ragang

38. Elevation: 688 m. (2,257 ft.)
No. of Eruptions: 5
Last Eruption: 1924
Mt. Type: Cinder Cone
A.k.a. Mt. Babuyan
Municipality: Calayan
Province: Cagayan
Region: Cagayan Valley
22. Smith Volcano

39. Elevation: 311 m. (1,020 ft.)
No. of Eruptions: 33
Last Eruption: June 6, 2024
Mt. Type: Caldera
Location: Talisay and San
Nicolas, Batangas
Etymology: “Taal” is a
Tagalog word in the
Batangueno dialect which
means true, genuine, and
pure.
23. Taal Volcano

41. •The effects of volcanic eruptions can be divided
into primary and secondary effects.
•The primary effects are immediate and come
from the eruption itself.
•The secondary effects result from the primary
effects.
EFFECTS OF VOLCANIC ERUPTIONS:

42. 1. Volcanic gases: All magma contains dissolved gases. These
gases are mainly steam, carbon dioxide and compounds of
sulphur and chlorine.
2. Lava flows: These are streams of molten rock.
3. Pyroclastic flows - These are high speed avalanches of hot
ash, rock fragments and gas which move down the sides of
a volcano. These flows occur when the vent area or ash
column collapses.
PRIMARY EFFECTS OF VOLCANIC ERUPTIONS:

43. 1. Lahars - These are mixtures of water, rock, ash, sand and
mud that originate from the slopes of a volcano. Lahars
often happen because of heavy rainfall eroding volcanic
deposits.
2. Landslides - Heat from cooling magma can cause
hydrothermal alteration of the rocks, turning sections of
them into clay. This weakens the rocks and increases the
risk of slope failures.
SECONDARY EFFECTS OF VOLCANIC
ERUPTIONS:

44. 3. Flooding - Explosive eruptions can change the surface areas
around a volcano and could disrupt drainage patterns, leading
to long term flooding.
Other Secondary Effects of Volcanic Eruptions:
4. Food and water supply interrupted;
5. Homelessness; 6. Businesses forced to close; 7. High Cost of
insurance claims; 8. Unemployment; and 9. Long-term issues
with the tourism industry.
SECONDARY EFFECTS OF VOLCANIC
ERUPTIONS:

45. Six (6) ways volcanoes benefit our
Environment:
1. Atmospheric cooling;
2. Land formation;
3. Water production;
4. Fertile land;
5. Geothermal energy; and
6. Source of raw materials.
BENEFICIAL EFFECTS OF VOLCANOES:

46. Volcanic Eruption can cause heavy damage to human life
and property.
Although volcanic eruptions are threats to human life, but
they have beneficial effects to the area.
The land areas where the eruption occurred would be
enriched with minerals and making the land fertile.
They have helped create the beautiful Philippine Islands
and have boosted tourism activities in these areas.
CONCLUSION:

47. Famous Quotes on Volcanoes:
“The origin of volcanic energy is one of the blankest mysteries
of science, and it strange indeed, that a class of phenomena so
long familiar to the human race and so zealously studied through
all the ages should be so utterly without explanation.”
By Clarence Edward Dutton (1841-1912), American geologist who was the first head
of the USGS division of volcanic geology (1887). He coined the term “isostacy” for
his explanation that continents rise higher on the Earth’s surface by virtue of their
less dense crustal rock.
https://todayinsci.com/D/Dutton_Clarence/DuttonClarence-Quotations.htm

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