Impacts And Responses

Question 1

What are primary impacts?

Answer 1

Those that occur immediately following a volcanic eruption.

Question 2

What are secondary impacts?

Answer 2

Those that occur in the days and weeks following an eruption.

Question 3

What are the environmental impacts of a volcanic eruption?

Answer 3

• fires caused by lava flows and pyroclastic flows

• acid rain as a result of SO2 being released into the atmosphere

• release of CO2 from burning of plants

• aerosols released from eruption create a cooling effect (can stay in the stratosphere up to 3 years).

Question 4

What are the social impacts of a volcanic eruption?

Answer 4

• food/water shortages due to crop damage and water supplies contaminated by ash fall

• people injured or killed by pyroclastic flows or increased CO2, causing suffocation.

• lahars injure and kill people

• psychological problems

• loss of shelter

• evacuation - malnutrition due to change in diet (leading to further deaths)

• Isolated communities more susceptible to disease after evacuation

Question 5

What are the economic impacts of a volcanic eruption?

Answer 5

• lava and pyroclastic flows destroy roads and cause buildings to collapse

• lahars cause further destruction to roads and buildings, blocking emergency services, destroying businesses and causing high levels of unemployment.

Question 6

What are the political impacts of a volcanic eruption?

Answer 6

• Conflict - caused by increased competition for resources (eg housing, food, water, medicine and aid)

• more extreme political parties emerging due to desperate and scared people

Question 7

What are the short term responses of a volcanic eruption?

Answer 7

• evacuation of people at risk

• international aid

• deployment of emergency services

• aid from within the country sent to the area

Question 8

What are the long term responses of a volcanic eruption?

Answer 8

• risk management

• alert systems

• storage of emergency food, water and aid supplies

• creation of hazard maps to evacuation

Question 9

Define preparedness

Answer 9

The state of readiness for a volcanic eruption

Question 10

Define mitigation

Answer 10

The action of reducing the severity or seriousness of a volcanic eruption

Question 11

Define adaptation

Answer 11

The action of changing or adapting behaviour in order to reduce the severity of a volcanic eruption

Question 12

List 6 ways of preparing for an eruption

Answer 12

• monitoring gas emissions

• ground deformation

• thermal monitoring

• satellite images and remote sensing

• mass movements and mass failures

• seismic activity

Question 13

Describe monitoring gas emissions

Answer 13

• the main gas is sulphur dioxide

• an increase in gas quantity ca signal the start is volcanic activity

• gas levels drop rapidly in the few hours before an eruption

Question 14

Describe ground deformation

Answer 14

• magma moving in the lithosphere can deform the ground above

• volcanoes swell prior to an eruption due to gathering of magma

Question 15

Describe thermal monitoring

Answer 15

• magma movement and changes in gas release can alter temperatures

• magma heats up groundwater

Question 16

Describe satellite images and remote sensing

Answer 16

• monitors changes in volcanoes from the surface

• images can be used to compare to previous times

Question 17

Describe mass movement and mass failures

Answer 17

• movement of the land can happen before, during or after an eruption

• can show evidence of past activity and suggest if deformation is happening

Question 18

Describe seismic activity

Answer 18

• an increased frequency and intensity of earthquakes can signal an imminent eruption

• detected by seismometres producing seismographs

• short period quake - caused by the breaking and fracturing of rock as magma is forced upwards

• long period quake - caused by an increase in gas pressure throughout the vents and chambers

• harmonic tremor - caused by magma pushing against rock below the surface creating a humming effect