UNIT 3: VOLCANOES

Question 1

Parts of a Volcano (5) [ Top -> Bottom ]

Answer 1

1. Pyroclastic / Tephra
2. Vent
3. Crater
4. Conduit
5. Magma Chamber

Question 2

upward movement of molten rock to low pressure environment

Answer 2

decompression melting

Question 3

formed in
1. hotspots
2. mid-ocean ridges

Answer 3

decompression melting

Question 4

formed in
1. subduction zones
2. island arcs

Answer 4

flux melting

Question 5

when H2O / CO2 is added to rock

Answer 5

flux melting

Question 6

when a plate sinks underneath another

Answer 6

subduction zone

Question 7

when equilibrium of lithostatic & magmastatic pressure is interrupted due to change of the latter

Answer 7

eruption

Question 8

expresses size of volcanic eruptions

Answer 8

Volcanic Explosive Index (VEI)

Question 9

VEI is based on (3)

Answer 9

1. Volume of erupted ash
2. Duration of eruption
3. Type of explosion

Question 10

Factors of Viscosity (3)

Answer 10

1. Temperature
2. Composition
3. Dissolved Gases

Question 11

ejected molten rock from volcano

Answer 11

lava

Question 12

Magma Compositions (3)

Answer 12

1. Basaltic
2. Andesitic
3. Rhyolitic

Question 13

[COMPOSITION]
1. Silica Content - Least

Answer 13

Basaltic

Question 14

[COMPOSITION]
1. Viscosity - Low
2. Explosivity - Least

Answer 14

Basaltic

Question 15

[COMPOSITION]
Shield and Cinder Cones

Answer 15

Basaltic

Question 16

[COMPOSITION]
1. Silica Content - Most

Answer 16

Rhyolitic

Question 17

[COMPOSITION]
1. Viscosity - High
2. Explosivity - Greatest

Answer 17

Rhyolitic

Question 18

[COMPOSITION]
Lava Domes

Answer 18

Rhyolitic

Question 19

volcano deaths are caused mostly by

Answer 19

the explosive shower of the molten rocks

Question 20

active ingredients needed for the volcanoes to erupt

Answer 20

dissolved gases / volatiles

Question 21

volatiles depend on the _____ of the magma

Answer 21

composition

Question 22

[GAS]
1. Smell – lighting a match
2. Colorless

Answer 22

SO2 / Sulfur Dioxide

Question 23

[GAS]
1. Smell - Rotten Egg
2. Colorless

Answer 23

H2S / Hydrogen Sulfide

Question 24

[GAS]
1. Pale yellow

Answer 24

Fluorine / F2

Question 25

bone degeneration / mottling of teeth

Answer 25

fluorosis

Question 26

[GAS] 1. Colorless OR Fuming Liquid

Answer 26

Hydrochloric Acid / HCl

Question 27

reaction of SO2 to water

Answer 27

acid rain

Question 28

ejected materials such as volcanic rocks / gases / fragments

Answer 28

pyroclastic materials / tephra

Question 29

pyroclastic materials a.k.a

Answer 29

tephra

Question 30

Types of Tephra (3)

Answer 30

1. Pumice 2. Scoria 3. Pele

Question 31

[TEPHRA] ORIGIN: Plinian COMP: Gas rich high silica content TEXTURE: Lots of voids

Answer 31

Pumice

Question 32

[TEPHRA] ORIGIN: Strombolian COMP: Andesite & Basaltic TEXTURE: Vesicular

Answer 32

Scoria

Question 33

[TEPHRA] ORIGIN: Eruption of basaltic lava COMP: Basaltic lava TEXTURE: Tear drop / hair like

Answer 33

Pele

Question 34

mixture of different types of tephra moving down the slides of volcanic crater at high speeds

Answer 34

tephra flows

Question 35

falling of fine materials / ballistic projectiles from the sky

Answer 35

tephra falls

Question 36

Types of Tephra Flow (3)

Answer 36

1. Merapi 2. Pelean 3. Soufriere

Question 37

[TEPHRA FLOW] gravitational collapse of a lava dome

Answer 37

Merapi

Question 38

[TEPHRA FLOW] release of nuee ardente

Answer 38

Merapi

Question 39

[TEPHRA FLOW] turbulent fast movement of hot gas

Answer 39

nuee ardente

Question 40

[TEPHRA FLOW] formation of block-and-ash deposit

Answer 40

Merapi

Question 41

[TEPHRA FLOW] dome that blocks the conduit is exploded under pressure

Answer 41

Pelean

Question 42

[TEPHRA FLOW] collapse of eruption due to loss of pressure

Answer 42

Soufriere

Question 43

[TEPHRA FLOW] results in a pumice flow

Answer 43

Soufriere

Question 44

Effects of Tephra Flow (4)

Answer 44

1. Burns 2. Impact and Burial 3. Inhalation of hot ash and gases 4. Lahars and flooding

Question 45

size classification of tephra that's a little bigger than ash

Answer 45

lapilli

Question 46

Types of Projectiles

Answer 46

1. Volcanic Bombs 2. Volcanic Blocks 3. Lapilli

Question 47

[TYPE OF PROJECTILE] from fresh magma

Answer 47

Volcanic Bombs

Question 48

[TYPE OF PROJECTILE] from walls of the vent / crater

Answer 48

Volcanic Blocks

Question 49

wet cement-like mixture of volcanic material

Answer 49

lahar

Question 50

lahars mostly occur in _____ volcanoes

Answer 50

composite

Question 51

Lahar Sources (3)

Answer 51

1. Rainfall 2. Crater lakes 3. Snow-covered tops