General = Volcanoes

Question 1

Vulcancity

Answer 1

Refers to all volcanic activities related to magma forced through crust

Question 2

Volcano (2)

Answer 2

Openings in earths crust
Lava ash and gas erupt

Question 3

Constructive margin - oceanic (2)

Answer 3

Oceanic ridges
Mid Atlantic ridge

Question 4

Constructive - Continental (2+)

Answer 4

Rift Valley
African Rift Valley - mt Kilimanjaro

Question 5

Destructive (2)

Answer 5

Ring of fire - Pacific Ocean
Most Violent

Question 6

Intraplate (3)

Answer 6

Over hotspots
Middle of pacific
Hawaiian islands

Question 7

Constructive type of lava

Answer 7

Basaltic

Question 8

Constructive characteristics (3)

Answer 8

Runny
Less viscous
Low in silica

Question 9

Constructive type of eruption (2)

Answer 9

Little violence
Gas escapes easily

Question 10

Constructive - form (2)

Answer 10

Shield volcano
Lava only

Question 11

Destructive - type of magma

Answer 11

Acidic

Question 12

Destructive lava characteristics (3)

Answer 12

Slow flowing
Viscous
High in silica

Question 13

Destructive - type of eruption

Answer 13

Potentially explosive

Question 14

Destructive - hazards (3)

Answer 14

Tephra
Pyroclastic flow
Ash + gas

Question 15

Destructive - form (2)

Answer 15

Composite cone
Layers ash and lava

Question 16

Primary hazards (6)

Answer 16

Lava flows
Pyroclastic flow
Tephra
Nuees ardentes
Ash fallout
Gases

Question 17

Secondary hazards (4)

Answer 17

Mudflows
Landslides
Tsunamis
Acid rain

Question 18

Lava flow (2++)

Answer 18

Basaltic = higher temp + flows for longer
Acid lava = slower + block neck of volcano = explosions

Question 19

Pyroclastic flow (3)

Answer 19

Hot rock, ash and gases rising
Moves at a rapid speed = up to 200m/s
Temperatures are between 350-1000°C

Question 20

Tephra (3)

Answer 20

Solid rock ejected from volcano
Largest = 1m in diameter = death
Smallest = carried for great distances

Question 21

Nuees ardente (3)

Answer 21

‘Glowing cloud’
Dense, rapid cloud of hot gases, ashes, and lava fragments
Type of pyroclastic flow

Question 22

Ash fallout (4+)

Answer 22

Ejected high in atmosphere
Can cover large area
Highly abrasive = breathing problems, disrupt machinery
Obstruct sunlight, reduce visibility and temps

Question 23

Volcanic gases (5)

Answer 23

Dominated by steam
Carbon monoxide, hydrogen sulphide, sulphur dioxide, and chlorine

Question 24

Mudflows / Lahars (3)

Answer 24

Formed when ash and other volcanic material mix with water
Speed = 60km/h
Highly erosive

Question 25

Acid rain (2+)

Answer 25

Volcanoes emit sulphurous gas = acidic rainwater when combined with atmospheric moisture

Question 26

Magnitude (2)

Answer 26

Logarithmic scale
Volcanic exclusivity index

Question 27

Frequency (3+)

Answer 27

Basaltic lava = continuous
Destructive = acidic lava infrequently = dormant
Yellowstone supervolcano = 3 times in 2.1million years

Question 28

Warning signs of volcano (4)

Answer 28

Measure local seismic activity = seismometer
Ground deformation = tiltometer
Changes in conc. of Co2 and sulphur dioxide = remote sensing
Temp of ground water = hydrological instruments

Question 29

Primary impacts examples (4+)

Answer 29

Direct result of volcano
Lava + pyroclastic flow = destroy roads and cause buildings to collapse
Ash = damage crops and water supply
Tephra + lava = kill people

Question 30

Secondary impacts examples (5+)

Answer 30

Lahars = kill, injure, damage roads = emergency services stopped = more death
Business collapse = unemployment
Psychological problems = loss
Shortages of food
Fires

Question 31

Protection offered through what (3+)

Answer 31

Risk management:
Preparedness = state of readiness
Mitigation = action of reducing severity of risk
Adaption = action if changing behaviour in order to reduce severity

Question 32

Prediction involves (3)

Answer 32

Hazard mapping = previous lava flow = geology

Question 33

Protection (5+)

Answer 33

Warnings issued
Instructions on how to act
Hazard maps = evacuation strategies
At risk areas = alert systems, shelters, evacuation camps
Emergency water + food supplies

Question 34

How many active volcanoes

Answer 34

1500

Question 35

% of eruptions associated with plate margins

Answer 35

95%