| Plate
Tectonics |
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Make
sure you know the structure of the earth
• Copy the diagram below and label the core, mantle
and crust.
•
Add labels to show the nature of each of those layers (its temperature
and state -solid, liquid or gas).
• Show the convection currents.
Explain what these are and how they occur.
Explain
what tectonic plates are
• Draw a diagram to show continental
and ocean plates floating on the mantle.
• Which type of plate goes deeper?
• Which is denser, and which
less dense?
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Key
idea
There are three types of plate margin.
• Constructive
• Destructive
• Passive/Conservative
Remember:
Constructive = new plate material is being created.
Destructive = old plate is being destroyed (it does
not mean that there are lots of destructive earthquakes
although that happens to be true as well!).
Passive or Conservative = the total amount of plate
is being conserved. None is being created and none is being
destroyed.
You
should know how all three types work, and be able to give
examples of each. Draw a simple diagram of each type of
plate, like the ones shown below, add labels and then learn
all three diagrams. Practice drawing them until you can
remember them perfectly.
| Destructive
Margin |
Constructive
Margin |
Conservative
Margin |
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!
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If
you are entered for the Foundation paper you will
probably not need to learn to draw these diagrams.
You are likely to be given the diagrams in the exam
and asked to label them. So ask your teacher for some
blank copies of the diagrams and practice labelling
them.
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Learn
about the nature of earthquakes and volcanoes
• Where do they occur?
• Which types of plate margin
are likely to have earthquakes, which to have volcanic eruptions
and which to have both?
Earthquakes
are caused by:
• plate movement (What makes
this happen?)
• friction between plates slowing
down their movement
• pressure building up;
• BANG!
Volcanoes
erupt when:
• plates rub together and the
friction causes heat
• heat makes rocks melt below
the surface
• pressure of gas in magma builds
up
• WHOOSH!
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Three
simple stages are given here. You should be able to remember
these quite easily, but you will need to be able to develop
them by providing some more detailed information.
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You
will probably need to be able to describe the following:
• An earthquake in an MEDC (for
example, Kyoto)
• An earthquake in an LEDC (for
example, Turkey)
• A very destructive volcanic eruption (for example,
Montserrat)
• A more predictable and less destructive eruption
(for example, Hawaii)
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!
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Make
sure one of your eruptions is in an MEDC and one in
an LEDC.
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Learn
about the effects of the volcano and the earthquake on
the areas they hit. For instance, you should be able to describe:
• immediate consequences (for
example, buildings collapse)
• medium-term consequences (for
example, fires spread because gas mains rupture; fire brigades
cannot get through to the scene of the fire)
• long-term consequences (for
example, the economy suffers over the next year or two because
factories supplying essential parts have been destroyed)
• some details of the loss of
life (but not too much gore!)
• damage to housing, infrastructure
and jobs
• psychological damage to survivors
(such as guilt or insecurity)
• any benefits (such as fertile
soil from the eruption; or the chance to build new, safer roads
after the earthquake)
• how the landscape is physically
altered by the hazard
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You
will get credit for using technical terms such as 'infrastructure'
correctly. 'Infrastructure' means 'structures built to keep
the economy and day-to-day life going, such as roads, railways,
electricity networks, water and sewage systems'. If you
show that you know what this word means, by using it sensibly
and in the right context, you won't need to waste time explaining
its meaning.
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You
should also learn how people are attempting to predict and
manage the problems caused by the hazard.
• Prediction - includes a lot
of interesting ideas on remote sensing and measurement. (Some
nice links with science and high technology developments can be
used here.)
• Warning systems.
• Evacuation systems.
• Earthquake practice drills (these are especially
well developed in Japan).
• Zoning of building to avoid danger areas (difficult
in LEDCs, where squatters are often desperate for any land to
build on).
• Better building regulations
to stop buildings collapsing.
• Insurance - which is only really an option for richer
countries - but even in MEDCs insurers will not take on risks
that are too dangerous.
• Well trained and equipped emergency rescue services.
• International help. For example, after a recent
earthquake in Turkey, rescuers even came from Greece to help,
despite a long history of hostility between the two countries.
A few months later, when an earthquake hit Greece, Turkish rescuers
came to help. Many people saw this as representing a great change
in attitudes between the two countries. Was it an example of good
coming from a disaster?
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Geography
teachers will all have their favourite stories like this.
You will remember those that your own teacher has told you.
They may make you groan, but they may also help you to remember
some useful ideas for the exam. Remember to keep them simple
and make sure you only use them where they are relevant.
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