Why do people live near volcanoes?
Fatalistic Approach- These people assume everything will always be alright because there has never been a problem before so why would there ever be one?
Acceptance Approach- Feeling that the benefits of the volcano site outweigh the risks or because people are too poor to move away from the volcano so they learn to live with it.
Adaptation Approach- People who live near volcanoes as they trust in the scientists predictions of an eruption and the ability to be evacuated to safety if an issue arises.
Reasons to live near volcanoes:
- Tourism- Tourists come to see the beautiful scenery of volcanic landslides and to gain health benefits from hot springs and mud baths. This opens up jobs for local people in hotels, restaurants, souvenir selling, transport and tour guides.
- Agriculture- Ash from previous eruptions breaks down into the soil filling it with minerals making it fertile allowing the growth of crops like pineapples, olives and rice that can be grown in few places.
- Geothermal energy- a renewable source obtained from heated water under the surface driving turbines that power an electricity generator.
- Mineral extraction- Valuable minerals like gold/silver/zinc are formed after a volcanic eruption.
Types of Volcanoes
Active- Ready to erupt at any time.
Dormant (sleeping)- Has not erupted for many years but may erupt again.
Extinct- Hasn't erupted for thousands/millions of years and most likely will never erupt again.
- Violent eruptions forcing volcanic bombs out of the vent.
- Narrow base
- Steep sides due to build up of ash and lava.
- Viscous, treacly lava that moves slowly
- Found at destructive plate margins.
- Gentle eruptions with no volcanic bombs
- Wide base due to size of lava flow.
- Gentle slopes made only of lava
- Runny lava that moves quickly.
- Found mainly at constructive plate margins.
Monitoring and Predicting volcanic eruptions
- Seismographs- Rising magma causes vibrations in the ground which can be picked up by seismographs. Earthquake patterns may change indicating an eruption.
- Ground Deformation- Rising magma bulges and moved the ground to make room for itself. Sensitive GP instruments via remote sensing detect ground deformation. Little movement can indicate chances of an eruption.
- Gas- Gas escaping from a volcano ca be a sign of an eruption.
- Water- More water escaping from the volcano or density change can be a sign of an imminent eruption.
Protection from Volcanoes
Emergency Action-When an eruption happens, danger zones should be restricted to make sure no one is put in danger and people should also be evacuated to a safer place. Flights over the area should be banned as ash can cause problems for planes which could endanger more lives of those travelling on the plane.
Forward Planning-This means getting ready for an eruption and includes stocking up on supplies so they have everything should evacuation be necessary, taking out insurance so replacing damaged property is cheaper and creating evacuation routes making it easier for people to know where to go to get to a safe place.
Education-People should be taught what to do in the event of an eruption through drills that will show people evacuation routes. This will decrease cofusion in the real event. Children should be taught about volcanoes in school which will help them to be ready for eruption so they asa well as adults will know what to do making evacuation more effective and quicker.
Mt. Etna Case Study
Mt Etna is located on the North East corner of the Italian island of Sicily on the African plate and close to the Ionian micro plate.
Mt Etna is on a destructive plate margin.The African plate moves Northwards where the Eurasian plate moves Southwards. One will sink under the other and start to melt building pressure released as a violent eruption.
There were a series of earthquakes measuring up to 4.3 on the richeter scale. Magma was thrown 100m into the air and then ash fell onto the city of Catonia continuously.
Key: ECONOMIC SOCIAL ENVIRONMENTAL
Primary impacts: Ski lifts destroyed by lava. 100 homes destroyed in Santa Verina. Hundreds of hetacres of forest on the slopes of the volcano were destroyed.
Secondary impacts: Catonia airport closed for 4 days due to ash on runway. Holiday homes were needed to house the homeless.
- Government- declares a state of emergency.
- Rescue workers- attempt to divert lava
- Army- Used bulldozers to crack tarmac in order to redirect lava away from populated areas.