Volcanic hazards - 3.1.5.3

Question 1

Exclusion Zone

Answer 1

An area around a volcano established by the government to keep people safe.

Question 2

Hazard Risk Mapping

Answer 2

A map which identifies places which will be adversely affected by a hazard

Question 3

Volcano

Answer 3

An opening in Earth’s crust that allows molten rock from beneath the crust to reach the surface

Question 4

Magma Chamber

Answer 4

A reservoir of magma within the earth’s crust beneath a volcano.

Question 5

Composite volcano

Answer 5

Composite volcano
Volcanoes with steep-sided flanks due to the thick sticky lava not travelling far from the vent. Made up of layers of lava and ash. Normally very explosive due to build-up of pressure.

Question 6

Shield volcano

Answer 6

A large volcano with shallow sides due to the runniness (low viscosity) of the lava. Not very explosive.

Question 7

Basaltic lava

Answer 7

Lava which has low viscosity and is very runny. It has a low silica content and allows gasses to escape easily.

Question 8

Rhyolitic lava

Answer 8

Lava has a high viscosity and is very thick. It has a high silica content and does not allow gases to escape.

Question 9

Volcanic Explosive Index

Answer 9

The name of the scale measures how powerful a volcanic eruption is by the volume of material erupted and the eruption cloud height.

Question 10

Nuee Ardent (Pyroclastic flow)

Answer 10

Fast-moving currents of hot gas and rock, travel away from the volcano. Very deadly.

Question 11

Ash fallout

Answer 11

Small bits of pulverized rock called tephra cover crops, pollute water supplies, collapse houses and affect planes in flight.

Question 12

Larhar

Answer 12

Mudflows occur when volcanic material mixes with large amounts of water

Question 13

Volcanic bombs

Answer 13

Solidified pieces of magma and rock were thrown from the volcano.

Question 14

Volcanic Gases

Answer 14

Volcanoes release sulphur dioxide, which when mixed with water vapour can create sulphuric acid

Question 15

Acid Rain

Answer 15

Volcanic gases (sulphuric dioxide) can react with water vapour in the atmosphere, which then falls as sulphuric acid.

Question 16

Volcanic global cooling

Answer 16

Volcanic ash and gases (sulphuric acid) high in the atmosphere are very effective at reflecting back sunlight and reducing solar insulation.

Question 17

Geothermal Energy

Answer 17

Heat from the earth is used to turn water into steam to turn a turbine and create electricity.

Question 18

Seismometer

Answer 18

An instrument that detects the vibrations caused by an earthquake (when the magma chamber is growing).

Question 19

Tiltmeter

Answer 19

A piece of equipment is used to detect if a volcano is growing bigger by measuring the tilt of its slopes. If it gets bigger an eruption is likely.

Question 20

Spectrometer

Answer 20

A device which measures the amount of sulphur dioxide in the gases released by a volcano. The more SOx there is, the more likely an eruption (because the magma must be near the surface).

Question 21

Thermal imaging

Answer 21

Satellites take heat images of the volcano which record how hot the volcano is beneath the surface. The hotter it is, the closer the magma is to the surface and the more likely it will erupt.

Question 22

Eyjafjallajokull

Answer 22

Icelandic volcano

Question 23

Meltwater floods

Answer 23

Jakulhlaup - water released from a glacier/ice cap by the heat of a volcano.

Question 24

Volcanic Ash Advisory channel

Answer 24

A research company tasked with determining the density of ash a plane can safely fly through.

Question 25

Subglacial volcano

Answer 25

A volcano lies underneath an ice cap which affects the eruption intensity and the type of ash produced.

Question 26

Pinatubo

Answer 26

Philippine volcano

Question 27

Subsistence farmers

Answer 27

Inhabitants of LICs who grow food to eat and sell.

Question 28

Asphyxiation

Answer 28

Ash clogs up the lungs of cattle which eventually leads to their death (1 million in the Philippines).

Question 29

Shanty Town

Answer 29

An area of poor-quality housing lacking basic amenities. Displaced people in the Philippines lived in these.

Question 30

Exclusion Zone

Answer 30

An area around a volcano established by the government to keep people safe.

Question 31

Hazard Risk Mapping

Answer 31

A map which identifies places which will be adversely affected by a hazard.

Question 32

Frequency

Answer 32

The rate at which something occurs over a particular period

Question 33

Regularity

Answer 33

Recurring at uniform intervals

Question 34

Predictability

Answer 34

making it possible to know in advance what to expect

Question 35

Primary effect

Answer 35

Impacts caused directly by the hazard (the immediate damage

Question 36

Secondary effect

Answer 36

Impacts caused by the primary effects (indirectly by the hazard) and happen after the event (the after-effects

Question 37

Social

Answer 37

The effect of an event on people i.e. injury, disease, death etc…

Question 38

Economic

Answer 38

The effect of an event on the economy in an area i.e. loss of income, jobs, and insurance costs etc…

Question 39

Environmental

Answer 39

The effect of an event on the economy in an area i.e. loss of income, jobs, and insurance costs etc…

Question 40

Political

Answer 40

The effects on the local and national government and its ability to make decisions that improve people’s quality of life i.e. spending, planning, regulations etc…

Question 41

Mitigation

Answer 41

Reduce the severity of an event and lessen its impact. This can be done pre- and post-hazard.

Question 42

Prevention

Answer 42

Actions aimed at stopping the natural hazard from starting.

Question 43

Adaption

Answer 43

How people change their behaviour or surroundings to minimise the risks and maximise the benefits.

Question 44

Preparedness

Answer 44

What happens before the natural hazard to minimise risk and vulnerability