SCIENCE 9: Volcanoes

Question 1

Molten rock beneath Earth’s surface.

Answer 1

Magma

Question 2

Molten rock that breaks through Earth’s surface and solidifies as it cools.

Answer 2

Lava

Question 3

A flat piece of rock formed when magma hardens in a crack of a volcano.

Answer 3

Sill

Question 4

An opening in Earth’s surface through which volcanic materials escape.

Answer 4

Vent

Question 5

An opening or vent in a planet’s crust from which molten rock, ash, and gases escape from below.

Answer 5

Volcano

Question 6

The side of a volcano.

Answer 6

Flank

Question 7

A depression larger than the original crater that forms when the summit is blown off or when the volcano collapses into the empty magma chamber.

Answer 7

Caldera

Question 8

Mouth of a volcano that surrounds a volcanic vent.

Answer 8

Crater

Question 9

An underground passage magma travels through.

Answer 9

Conduit

Question 10

Highest point, apex.

Answer 10

Summit

Question 11

Entrance of a volcano. The part of the conduit that eject lava and volcanic ash.

Answer 11

Throat

Question 12

Fragments of lava or rock smaller than 2mm size that are blasted into the air by volcanic explosions.

Answer 12

Ash

Question 13

A cloud of ash formed by volcanic explosions.

Answer 13

Ash Cloud

Question 14

A classification of volcanoes that have not erupted for the last 10,000 years.

Answer 14

Inactive Volcanoes

Question 15

Have not erupted for a very long time, but may erupt at a future time.

Answer 15

Dormant Volcanoes

Question 16

Has a record of eruption within the last 600 years (historical record) or 10,000 years ago based on the analyses of their materials.

Answer 16

Active Volcanoes

Question 17

A type of volcano that is almost a flat and broad like a warrior’s shield.

Answer 17

Shield Volcanoes

Question 18

Usually small and made up of pyroclasts or fragment of volcanic rocks that form steep slopes around their wide crater.

Answer 18

Pyroclastic Volcanoes

Question 19

A tall mountain with a crater on top which pyroclastic materials, gases and lava escape. Also known for its violent eruptions.

Answer 19

Stratovolcanoes

Question 20

Are found along the boundaries of tectonic plates, particularly divergent and convergent boundaries.

Answer 20

Continental Volcanoes

Question 21

Volcanoes that are usually found on the ocean floor.

Answer 21

Submarine Volcanoes

Question 22

Volcanoes found in high latitude countries like Iceland.

Answer 22

Subglacial Volcanoes

Question 23

A process which the two plates meet, one of them (usually the oceaning plate) goes under the continental plate.

Answer 23

Subduction

Question 24

What will be formed when two tectonic plates (contintental - continental) come together?

Answer 24

Volcano

Question 25

It is like a **jigsaw puzzle** which a **large chunk of plates on the Earth's lithosphere** (made up of crust and upper mantle).

Answer 25

**Tectonic Plates**

Question 26

Is the **property of a material's resistance to flow.** Also described as the **liquid's thickness or stickiness**. The **more viscous** and thicker the material is, the greater is its resistance to flow.

Answer 26

**Viscosity**

Question 27

What are the primary factors affecting the volcanic eruptive style.

Answer 27

* **Magma Temperature** * **Chemical Composition** * **Amount of Dissolved Gases**

Question 28

The **higher the temperature of magma is**, **the lower is its viscosity**.

Answer 28

**Magma Temperature**

Question 29

Magma's **high silica content are more viscous than those with low silica content**.

Answer 29

**Chemical Composition**

Question 30

**Gas (mainly *water vapor)* dissolved in magma tends to increase its ability to flow.**

Answer 30

**Amount of Dissolved Gases**

Question 31

Is a **stream-driven eruption**, as hot rocks come in **contact with water**. It is short-lived characterized by ash columns but may be an onset for a larger eruption.

Answer 31

**Hydrothermal**

Question 32

Is a **violent eruption due to contact between water and magma**. As a result, a large column of very fine ash, high speed and side-way emission of *pyroclastic* called **based surges** are observed.

Answer 32

**Phreatomagmatic**

Question 33

A periodic weak to violent eruption **characterized by fountains of lava**.

Answer 33

**Strombolian**

Question 34

Characterized by **tall eruption columns that reach up to 20 km high** with pyroclastic flow and ash fall tephra.

Answer 34

**Vulcanian**

Question 35

**Excessively explosive** type of eruption of gas and pyroclastics. Also considered as the **largest and most violent** of all types of volcanic eruption.

Answer 35

**Plinian** | Famous Example: Mt. Pinatubo last eruption (June 15, 1991)

Question 36

Mt. Mayon is an example of?

Answer 36

An **active stratovolcano**.

Question 37

A mixture of **volcanic ashes and dust** that is **mixed with water.**

Answer 37

**Lahar**

Question 38

Volcanic eruptions produce gases which are ____ and irritating on the skin.

Answer 38

**Dangerous**

Question 39

The **heat from deep inside the Earth is used to produce steam to generate electricity**.

Answer 39

**Geothermal Power Plants**

Question 40

The **heat flowing from the inside of the Earth is tapped as a source of *energy***.

Answer 40

**Geothermal Energy**

Question 41

The **heat coming from close to the Earth's surface to heat water or provide heat for buildings.**

Answer 41

**Geothermal Heat Pumps**

Question 42

Geothermal Power Plant works:

Answer 42

**Collection of Steam > Heat > Mechanical Energy > Electrical Energy**