Volcanoes (ch.3) Flashcards
(15 cards)
How do volcanoes form?
Volcanoes form as a result of constructive plate boundaries, i.e. Plates are pulled apart from each other
e.g. North American plate and Eurasian plate
Draw, label and explain the structure of a volcano
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Active Volcanoes
Volcanoes which erupt regularly e.g. Mount Etna, Sicily
Dormant Volcanoes
Volcanoes which haven’t erupted for a while but may erupt in the future e.g. Mt. Rainier, Washington, USA
Extinct Volcanoes
Volcanoes which haven’t erupted in historic times (last 10,000 years) and are unlikely to erupt again. e.g. Mt. Slemish Co. Antrim
Name and outline a volcanic island you have studied.
-Iceland
- Iceland is 20 million years old.
- It is a volcanic island located directly on top of the Mid-Atlantic Ridge.
- It has a number of volcanic mountains such Hekla and Krafla.
- It has many hot springs and geysers. Geysers are spouts of very hot water which has been heated by magma underground.
- Surtsey, a small island off the coast of Iceland, was formed in 1963 after many eruptions along the Mid-Atlantic Ridge.
Geyser
A spout of very hot water which has been heated by magma underground.
The Pacific Ring of Fire
A zone of active volcanoes running around the edge of the Pacific Ocean. These volcanoes are the most active in the world.
Draw the location of The Pacific Ring of Fire on a map.
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List three advantages of the existence of volcanoes
- Tourists often visit volcanic features such as hot springs. This brings in valuable revenue to the country and provides jobs for the local people in accommodation, transportation and retail.
- Geothermal energy is a renewable energy source which is generated when molten magma rises in the crust and heats water close to the Earth’s surface. It is used to generate electricity which heats people’s homes. 90% of homes in Iceland use geothermal energy. It is a cheap fuel.
- Iceland’s capital Reykjavik is one of the cleanest cities in the world, as it uses geothermal energy as a clean fuel source and has very low carbon dioxide emissions. The use of geothermal energy has improved air quality and, as a result, people’s health. It has also helped to reduce Iceland’s impact on climate change.
List three disadvantages of the existence of volcanoes
- In March 2010, a volcano called Eyjafjallajökull erupted in Iceland. By April, the glacier the volcano was under had melted and a hot cloud of volcanic glass erupted into the atmosphere. European air control immediately banned airplane flights. Airplanes were not allowed to fly for 6 days, with cancellations lasting 8 days. Over 100,000 flights, affecting 10 million people, were grounded. The impact was felt globally by airlines, and the overall cost was estimated at 1.3 billion euro.
- Iceland’s volcanic activity acts as a barrier to the spread of settlement. Most of the country’s population of 338,000 people lives in or near Reykjavik on the west coast. The Mid-Atlantic Ridge runs through the middle of Iceland and is marked by several volcanoes along its length. As a result, large-scale settlement tends to avoid the centre of the island.
- When volcanic eruptions occur, the prevailing wind (south-westerly) carries the ash cloud to the east. Reykjavik is located in the west of the island and avoids this hazard.
Outline an eruption which occurred in a developed country and how it was handled.
Japan
Mount Ontake
27 September 2014
Location: Honshu Island, Japan
Summary: Just over 3,000 metres high, the stratovolcano erupted without warning.
Deaths: 63
Social impact: No major injuries with the exception of deaths. Some hikers were trapped by the ash cloud and had to be rescued.
Economic impact: No major financial impact.
Buildings destroyed: The mountain was covered in a layer of ash that affected several buildings.
In reference to the volcanic eruption in a developed country which you explained previously, outline three ways in which the country’s status as a developed country affected its response to the eruption.
- Developed countries have better housing which have been designed to withstand the impact of volcanic eruptions. They are less likely to be destroyed in the event of a eruption.
- Their populations are educated about the hazards of volcanoes which can help save their lives during an eruption.
- Governments have more jurisdiction to ensure that large populations do not build up around volcanoes. Hazard mapping can predict the likely path of lava flows. This allows governments to create ‘exclusion zones within which people may not live.
Outline an eruption which occurred in a developing country and how it was handled.
Indonesia
Mount Sinabung
22 May 2014
Location: Karo, North Sumatra, Indonesia
Summary: The stratovolcano formed from the collision of the Indo-Australian Plate and the Eurasian plate. It has four craters.
Deaths: 16
Social Impact: 30,000 people were evacuated before the eruption. They were housed in temporary accommodation such as schools and public buildings.
Economic impact: Evacuated people were unable to tend to their farms. Crops were covered in ash. Farmers lost income as a result.
Buildings destroyed: Farms, trees and villages were covered in a layer of thick grey ash.
In reference to the volcanic eruption in a developing country which you explained previously, outline three ways in which the country’s status as a developing country affected its response to the eruption.
- Although the Indonesian government were aware that the eruption was going to occur, they did not have the resources to handle it.
- The people of the country have poor education about volcanic eruptions. This means they cannot prepare for an eruption.
- Poor housing which is unsuitable to withstand volcanic eruptions.
