Quarter 1 - Last quiz

Question 1

The Philippines is geographically located in the ___?

Answer 1

Pacific Ring of Fire or also known as the circum-Pacific Belt.

Question 2

This region is characterized by active volcanoes and frequent earthquakes. Its length is approximately 40,000 kilometers and borders the Pacific Ocean.

Answer 2

the Pacific Ring of Fire or also known as the circum-Pacific Belt.

Question 3

Around __ of the world’s volcanoes, comprised of more than ___ volcanoes, are in the Pacific Ring of Fire.

Answer 3

75%; 450

Question 4

In the Phi lippines, there are ___ active volcanoes based on the records of PHIVOLCS. These volcanoes erupted within the last ___ years.

Answer 4

23; 600

Question 5

3 Active Volcanoes in the Philippines

Answer 5

1. Mt. Mayon in Bicol Region
2. Mt. Kanlaon in Negros Oriental
3. Mt. Bulusan in Sorsogon Province

Question 6

Since July 2006, this volcano has had four eruptive phases (2008, 2009, 2013, 2014), bringing the total number of historical eruptions to 52.

Answer 6

Mayon Volcano

Question 7

This volcano had renewed volcanic activity towards the end of 2015.

Answer 7

Kanlaon Volcano

Question 8

After 2011, this volcano had an eruptive phase occurred in May-July 2015, with more
activity in February 2016.

Answer 8

Bulusan Volcano

Question 9

Why does the Philippines have many volcanoes?

Answer 9

The Philippines sits on a unique tectonic setting ideal to volcano formation. The archipelago is surrounded by subducting plates as manifested by the trenches that are related to volcano formation.

Question 10

The term signifies a vent, hill, or mountain from which molten or hot rocks with gaseous materials are or have been ejected.

Answer 10

Volcano

Question 11

The term also applies to craters, hills or mountains formed by removal of pre-existing materials of by accumulation of ejected materials.

Answer 11

Volcano

Question 12

Is a process wherein molten rock materials are emitted or ejected in the form of flowing masses of lava or fragmental particles called pyroclastic with gas from a crater, vent or fissure.

Answer 12

Volcanic Eruption

Question 13

PHIVOLCS Classification of volcanoes

Answer 13

1. Active
2. Inactive
3. Potentially Active

Question 14

A volcano is classified as active based on the following:

Answer 14

1. if it has had eruptions in historic times supported by numerous historical accounts;
2. if it has oral folkloric history which suggests an eruption that is remembered by our ancestors;
3. if it has shown indications of seismic activity and
4. if it has volcanic deposits less than 10,000 years as determined by radiometric dating.

Question 15

A volcano is said to be inactive if ___.

Answer 15

it has no record of eruptions and its form has been changed by agents of weathering and erosion with the formation of deep gullies.

Question 16

A volcano is said to be potentially active if ___.

Answer 16

it is geologically young-looking, which suggests it possibly erupted in less than 10,000 years. A volcano is said to be geomorphologically young as suggested by very little vegetation cover.

Question 17

Life Cycle of Volcanoes

Answer 17

1. Active: Has, is or showing signs that it will erupt
2. Dormant: Show signs or predicted to erupt
3. Extinct: Unlikely to erupt again

Question 18

Types of Volcanoes
There are different types of volcanoes based on the form or
shape of their edifice, which are dependent upon the type of eruptions a volcano is capable of and ultimately the
chemical composition of the magma it erupts.

Answer 18

1. Monogenetic cones (tuff/cones, cinder cones, maars)
2. Volcanic domes/Domes complexes
3. Strato-volcanoes
4. Calderas
5. Shield volcanoes

Question 19

Classification of Magma based on Silicon Dioxide Content

Answer 19

1. A basaltic magma is composed of the least silicon dioxide content, which is about 45 to 55%, contributes to least viscosity.
2. An andesitic magma is composed of an intermediate silicon dioxide content, which is about 55-65%, contributes to a moderate viscosity
3. A rhyolitic magma is composed of the highest silicon dioxide about 65 to 75%, which contributes to greatest viscosity.

Question 20

1. A ____ magma is composed of the least silicon dioxide content, which is about 45 to 55%, contributes to least viscosity.

Answer 20

Basaltic

Question 21

2. An ___ magma is composed of an intermediate silicon dioxide content, which is about 55-65%, contributes to a moderate viscosity.

Answer 21

Andesetic

Question 22

3. A ___ magma is composed of the highest silicon dioxide about 65 to 75%, which contributes to greatest viscosity.

Answer 22

Rhyolitic

Question 23

Low symmetrical accumulations of cinder (scoria) and or
tuff (ash). These volcanoes are usually associated with
low silica or basaltic magma, usually for during just one
eruption, and may be lateral vents associated with
bigger volcanic complexes.

Answer 23

Monogenetic cones (tuff/cones, cinder cones, maars)

Question 24

mound-shaped or convex volcanoes formed by repeated slow extrusion of viscous magma. Domes are associated with low- to high silica magma e.g. Hibok-hibok Volcano

Answer 24

Volcanic domes/ Domes complexes

Question 25

Cone-shaped volcanoes typically having one or several summit craters and formed by repeated alternate deposition of lava and pyroclastic. Stratovolcanoes are usually formed by intermediate silica or andesitic magma . e.g. Mayon
Volcano.

Answer 25

Strato-volcanoes

Question 26

Large volcanic edifices typically composed of several volcanic centers around a central 2 km wide crater. Calderas are formed by highly explosive eruptions in between long periods of dormancy and are typically associated with high-silica or rhyolitic magma, e.g. Taal Caldera

Answer 26

Calderas

Question 27

Gentle-sloped but large diameter volcanoes. Typically island volcanoes, partially submerged. Formed by frequent, long-period lava eruptions in rift zones, mantle hotspots. Low-high SiO2 (basaltic) magma. E.g. Kilauea, Mauna Loa, Pu’u O’o, Hawaii; Mt. Etna, Italy

Question 28

Types of Volcanic Eruptions

Answer 28

1. Phreatic or hydrothermal eruptions
2. Phreatomagmatic eruptions
3. Strombolian eruptions
4. Vulcanian eruptions
5. Plinian eruptions

Question 29

1. Steam-driven eruptions caused by contact of groundwater w/ hot country rocks (no magma involved)
2. Usually precursory to magmatic eruptions
3. Short ash columns, ashfall

Answer 29

Phreatic

Question 30

1. Very violent eruption generated by the explosive contact of erupting magma with water
2. Voluminous, slightly tall ash columns, laterally-projected pyroclastic currents (base surges) & blasts

Answer 30

Phreatomagmatic

Question 31

1. Canon-like explosions produced by the detonation of a solidified magma plug in the vent by gas accumulated beneath it
2. Ca. 20 km tall eruption columns; pyroclastic flows, ashfall

Answer 31

Vulcanian

Question 32

1. Weak to violent eruption of gas- charged fluid magma characterized by lava fountaining & flowing
2. Lava flows

Answer 32

Strombolian

Question 33

1. Very explosive, energetic release of voluminous magmatic gas, fragmented magma w/c propel w/ great force high in the air, forming huge mushroom clouds
2. Tall eruption column >40 km high, penetrating stratosphere
3. Well-defined umbrella cloud
4. Extensive ashfall
5. Pyroclastic flows
6. Large volcanic calderas

Answer 33

Plinian

Question 34

Volcanic phenomena directly associated with
eruption

Answer 34

1. Lava flow, dome growth
2. Pyroclastic flow, pyroclastic surge, lateral blast
3. Tephra fall - ash fall, volcanic bomb
4. Volcanic gas

Question 35

Volcanic phenomena indirectly associated
with eruption

Answer 35

1. Lahar, flooding
2. Debris avalanche, landslide
3. Tsunami, seiche
4. Subsidence, fissuring
5. Secondary/hydrothermal explosion
6. Secondary pyroclastic flow.