2.b types of volcanoes and impacts Flashcards
What is an active volcano?
An active volcano is defined as when there is evidence of magma moving underground and accompanying small earthquakes - and have a recent history of eruptions.
What are the three classifications of volcanoes?
Active / extinct and violent
What is an extinct volcano?
Are volcanoes that are not expected to erupt within the future.
What is a Dormant volcano?
Volcanoes that have erupted in the past but show no signs of activity today but may erupt at a future time
Why is the classification of volcanoes confusing?
It is difficult to distinguish between them as scientists are in disagreement about the classification of these so is blurred boundaries between them.
Social impacts of volcanic eruptions
- House insurance increased
- Damage to property / infrastructure
- People evacuated from houses
- Transportation routes closed
- Injuries of residents
- Deaths
- Being cut off from help - if in a remote area
- Respiratory issues
- Food and water insecurity
Economic impacts of volcanic eruptions
- Closure of national parks / businesses close to the area
- House insurance ^ / ^ in insurance
- Cost to replace infrastructure
- Airports having to close - losing business / closure of air space
- Closure of transport links
- Loss of crops
- Growth of tourism industry → can lead to an economic boom (long term)
But short term a lack of tourism
Environmental impacts of volcanic eruptions
- Set of minor earthquakes
- New lava flows emitted
- Sulfur dioxide can lead to risk of respiratory issues
- Impact on landslide
- Impact on climate (global cooling to an extent)
- Crop failure - covered in ash
POSITIVES
* Increased mineral deposits -> to fertility of soil / quarrying
- Fertile soils created - for farming
Why do people live near volcanoes list the four reasons?
- volcanic soil
- geo-thermal power
- mineralisaton
- tourism
Explain the volcanic soil reasoning for living near a volcano?
- Mineral rich volcanic soils formed the weathering of lava and ash have attracted farmers to work on the lower slopes
MT Etna (sicily) - Despite the ever present danger of further eruptions and lava flow
Explain the geo-thermal power reasoning for living near a volcano?
- Produced by heat generated by volcanic activity is harnessed by a number of countries to produce energy
- Generates jobs/ affordable electricity
Iceland + USA
Explain the mineralisation reasoning for living near a volcano?
Is associated with igneous activity
* Minerals (tin,copper,silver,zinc) are within the magma
* Important in economies which are mined
Copper in Chile etc
Explain the tourism reasoning for living at the base of a volcano?
Many tourists drawn to MT Etna
Cable cars + strenuous walk
MT Vesuvius → large numbers climb
Hot springs,mud volcanoes, geysers → tourist attractions
Some get guided tours
What is the volcanic explosivity index (VEI)
- Scale of 0-8
- Measures the magnitude and intensity of eruptions
Each increase in scale represents a (10 fold increase)
0- lava flows (Mauna Loa hawaii) 7= Mt Tambora, indonesia in largest living memory
In every increase in scale in the VEI how much does it increase by
10 fold
What is a hazard event profile?
A way of characterising a volcanic hazard
* duration
* magnitude
* speed
* frequency
* economic damage
* deathtoll and injury
