Exam Notes - Tectonic Plates

Question 1

Igneous rock

Answer 1

Formed through cooling/solidification of magma or lava

Question 2

Metamorphic rock

Answer 2

The resulting transformation of a pre-existing rock. Original rock is subjected to very high heat/pressure, which causes obvious physical or chemical changes

Question 3

Sedimentary rock

Answer 3

Formed by the deposition of material at the earths surface

Question 4

Types of plate boundaries

Answer 4

• Converging
• Diverging
• Transformation

Question 5

Landforms associated with plate boundaries

Answer 5

Fold fault
rift valleys
ocean ridges
deep sea trenches,
island arcs

Question 6

Converging plate boundary (subduction zone)

Answer 6

• oceanic plate subduct underneath continental plate
• oceanic edge is destroyed
• continental crust leading edge is crumpled into fold mountains

Question 7

Diverging plate boundary

Answer 7

• creates either a deep sea trench or rift valley
• crust cracks, exposing magma from the crust
• creates new ocean floor or mid-ocean ridges

Question 8

Converging plate boundary (collision zone)

Answer 8

• 2 plates that are the same density converge
• neither subducts, instead the leading boundary crumples to form fold mountains
• volcanoes can also be formed

Question 9

Transform fault boundary

Answer 9

• 2 plates are moving in opposite directions, parallel to each other
• can occur between any types of plates
• doesn’t create landforms
• causes earthquakes

Question 10

Types of Volcanoes

Answer 10

Fissure
Shield
Dome
Ash-cinder
Composite
Caldera

Question 11

Fissure

Answer 11

low profile
created at divergent plate boundaries
basaltic
gentle eruption

Question 12

Caldera

Answer 12

Medium profile
skeleton of pre-existing volcano
rhyolitic
violent

Question 13

Shield

Answer 13

Low profile/dome shape
Composed of individual particles from past eruptions
Andesitic
Intermediate

Question 14

Cinder/ash

Answer 14

High profile
Crustal rock, lava flows too thin and far to cool, creating a low dome shape
andesitic
Intermediate

Question 15

Dome/Acid

Answer 15

High profile
Thick lava cools quickly and builds up volcano
andesitic/rhyolitic
Intermediate eruptions

Question 16

Composite volcano

Answer 16

High profile/classic volcano
Composed of alternate layers of magma and ash
rhyolitic lava
violent

Question 17

Types of lava

Answer 17

rhyolitic
andesitic
basaltic

Question 18

Rhyolitic

Answer 18

High silica content

very viscous

Question 19

Andesitic

Answer 19

Medium viscosity and silica content

Question 20

Basaltic

Answer 20

Highly fluid

Question 21

Magma vs Lava

Answer 21

Magma is below ground, lava is above

Question 22

Focus

Answer 22

Where the earthquake occurs on the tectonic plates

Question 23

Epicenter

Answer 23

The spot on the earth directly above where the earthquake is occuring

Question 24

Richter Scale

Answer 24

Measurement of how big the magnitude of an earthquake is

Question 25

P Waves

Answer 25

The first waves to arrive after an earthquake
“Pressure” waves
highest velocity

Question 26

S waves

Answer 26

secondary waves

move perpendicular to surface

Question 27

Primary Hazards

Answer 27

Ash clouds
Directed blast
lava flows
Nuee Ardente
Pyroclastic flows

Question 28

Ash Clouds

Answer 28

Rain down on surrounding areas, can bury areas many meters thick

Question 29

Lava flows

Answer 29

Commonly accompany volcanic eruptions
Can cause secondaru
usually accompanied by poisonous gases

Question 30

Directed blast

Answer 30

Explosion of vent, throws debris in the air

Question 31

Nuee Ardente

Answer 31

Ash and gas charged cloud that travels rapidly down the slope of volcano

Question 32

Pyroclastic Flows

Answer 32

Dense avalanche of hot gas, ash and blocks that cascade down slopes during eruption
Can also form in less energetic eruptions when material “boils” over

Question 33

Secondary Hazards of Volcanoes

Answer 33

Lahars (mudflow)
Tsunamis
Fire
Mass wasting
Disease

Question 34

Lahars

Answer 34

Debris flow
Slurries of water and rock particles that behave like wet concrete associated with volcanic eruptions
Extremely destructive but topographically controlled

Question 35

Tsunamis

Answer 35

Volcano is near the ocean, side blows off (possibly from direct blast) huge amount of debris falls into ocean creating a tsunami

Question 36

Mass Wasting

Answer 36

Icy ground cover of volcano melts and mixes with soil to form mud as the magma in the volcano stirs preceding eruption

Question 37

Disease

Answer 37

Health centres destroyed
Cut off from getting supplies
Lack of health care