The Restless Earth Flashcards
Name the plate margin where two plates are moving towards eachother
Destructive
Name two differences between continental and oceanic plates
Oceanic = denser Continental = thicker
What is an ocean trench?
Very deep sections of the ocean floor where the oceanic plate goes down
Name the type of plate margin where two plates are moving sideways against eachother
Conservative
How are fold mountains formed?
When tectonic plates collide the sedimentary rocks that have built up between them are folded and fired upwards to form mountains.
Give one way that humans use fold mountain areas
Farming Hydro electric power Mining Forestry Tourism (eg skiing/mountain biking)
Describe how farmers have adapted to the steep slopes in fold mountain areas.
- man made defences are used to protect against avalanches and rock slides.
- animals are grazed in most high areas as the soil isn’t great for growing crops.
- roads have been built over passes.
Name one range of fold mountains
The Alps
Name 3 ways that humans use the Alps
Walking
Mountain bikini
Skiing
Snow boarding
What’s magma called when it erupts onto the surface?
Lava
Which type of volcano is made up of layers of ash and lava?
Composite volcano
Eg Mount Fuji
Which type of volcano is formed when lava is runny?
Shield volcanoes
Eg Mauna Loa
Name a volcanic eruption and state where it happened
Soufriere Hills Volcano in Montserrat
Describe 2 negative secondary impacts of Montserrat
- Large areas were covered with volcanic material- the capital city Plymouth was buried under 12m of mud and ash.
- Over 20 villages and two thirds of homes on the island were destroyed by pyroclastic flows.
- Vegetation and farmland were destroyed.
- 19 people died and 7 were injured.
- Schools, hospitals, the airport and the port were destroyed.
Describe 2 secondary impacts of the eruption of Montserrat
- Fires destroyed many buildings including local government offices, the police headquarters and the town central petrol station.
- Tourists stayed away and businesses were destroyed, disrupting the economy.
- Population decline - 8000 of the islands 12000 inhabitants have left since the eruptions began in 1995.
Give two positive impacts of the eruption in Montserrat
- Volcanic ash from the eruption has improved soil fertility.
- Tourism has increased as people come to see the volcano.
Give to immediate responses to the eruption in Montserrat
- People were evacuated from the south to safe areas in the north.
- Shelters were built to house evacuees.
- Temporary infrastructure was also built, eg roads and electricity supplies.
- The UK provided £17 million of emergency aid.
- Local emergency services provided support units to search for and rescue survivors.
Give two long term responses to the eruption in Montserrat
- A risk map was crated and an exclusion zone is in place. The south of the island is off-limits while the volcano is still active.
- The UK has provided £41 million to develop the North of the island - new docks, and airport and houses have been built in the north.
- The Montserrat Volcano Observatory has been set up to try and predict future eruptions.
Where do super-volcanoes form?
At destructive ate margins or over parts of the mantle that are really hot (called hot spots).
Give one way that a super volcano’s eruption is different from a volcanic eruption.
A super volcanic eruption will throw out thousands of cubic km of rock ash and lava (much more than normal volcanoes, which usually produce a couple of cubic km)
Give one predicted effect of a super volcanic eruption
- A thick cloud of super heated gas and ash will flow at high speed from the volcano, killing, burning and burying everything it touches. Everything within tens of miles will be destroyed.
- Ash will shoot kilometres into the air and block out almost all daylight over whole continents.
What causes earthquakes?
Plates can get stuck against eachother. When they become unstuck you get earthquakes.
What’s the point in the earth where an earthquake starts?
The focus
What’s the name of the point on the surface of the earth where an earthquake starts?
The epicentre.
What does the Richter scale measure?
This measures the amount of energy released by an earthquake (called the magnitude)
Give an example of an earthquake in a rich part of the world
L’aquila, Italy
Give an example of an earthquake in a poor let of the world.
Kashmir, Pakistan
What causes a tsunami?
A tsunami is a series of enormous waves caused when huge amounts of water get displaced. This often happens when a volcano erupts or an earthquake happens out at sea.
