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1. Features of an earthquake.2. Prediction, Protection and Preparing for earthquakes.
How many earthquakes have there been in the last 24hrs? HEREWhere do earthquakes occur?
Why do earthquakes happen?
Features of an earthquake• Epicentre and focus• Watch it here
• A = • B =
Features of an earthquake
Features of an earthquake
How can we measure earthquakes?
• There are two ways of measuring earthquakes;
1. The Richter Scale 2. The Mercalli Scale
Watch 30 seconds of this video
Features of an earthquake
1. Richter Scale • Although the Richter Scale has no upper
limit, the largest known shocks have had magnitudes in the 8.8 to 8.9 range.
• It is a logarithmic scale which means that a size ‘6’ on the Richter Scale is 10 times larger than a size ’5’ and 100 times larger than a size ‘4’.
• Measured using a seismograph.• Very common.
Features of an earthquake
Features of an earthquake
2. Mercalli Scale • Based on the effects of
an earthquake. E.g windows crack, tiles fall off roofs or bridges collapse.
• The scale goes from 1 to 12.
• Not very common.
2. Prediction, Protection and Preparing for earthquakes.
1. Can earthquakes be Predicted?
• Watch this video and write down what can be done to predict earthquakes.
Prediction, protection and preparation for earthquakes
1. Prediction
water levels can rise in wells and lakes because of cracks in the rock
foreshocks before the main quake can be detected by a seismometer
animals can act strangely before the earthquake
a tiltmeter can check any movement within the rocks
1. Can earthquakes be predicted?
Prediction, protection and preparation for earthquakes
2. Protection • Buildings can be made to protect people
who live and work in them. • Building codes can regulate the
design of buildings so that they are strong.
• For example the Transamerica Pyramid in San Francisco.
Prediction, protection and preparation for earthquakes
Two ways a building can withstand an Earthquake
Earthquake proof buildingsSkyscraper modification
– A wide base leading up to a thinner point helps to channel vibrations up and the building is designed not to sway from side to side.
– Large scale dampers can be placed on the bottom of buildings to help absorb the earth vibrations.
Prediction, protection and preparation for earthquakes
Earthquake proof buildings What is happening in Los Angeles?
– LA buildings Video
P30-31
Prediction, protection and preparation for earthquakes
Iceland, HEP station
3. Preparation
What should people pack in their emergency kit?Video here
make an emergency planBooklet here
organize regular ‘earthquake practices’ for offices and schoolsE.g. Japan has one annually - video
advise people to plan for an earthquake (e.g. tell them to turn off the gas, find a ‘safe’ place in their homes, pack an emergency kit)
enforce regulations to make some buildings earthquake proof
3. Preparation for an earthquake?
Prediction, protection and preparation for earthquakes
Prediction, protection and preparation for earthquakes
Prediction, protection and preparation for earthquakes
YOUR TURN!• Imagine you are an
architect and you need to come up with a design for a 20 story government office block in Haiti, where you know earthquakes strike.
• You need to come up with a building design that is as earthquake proof as you can make it!
• P31 has some more ideas to help
• Design a poster that will be put up telling people what to do before, during and after an earthquake.
• You will need to think about where people should shelter, what they should pack in earthquake emergency kit and how to look after themselves before help arrives.
Prediction, protection and preparation for earthquakes
What to do in an earthquake?
1. Drop to the floor and hold on!
Find a surface to hind under fast to protect yourself from falling debris
2. ……………….. 3. ………………..
Questions to Think about• How will you stop the building from
collapsing?• If it does not fall how will you prevent
accidents in the building as it moves?• What about falling glass and rubble on
the people outside?• What about problems after the
earthquake (fire, gas and water leaks, no power)?
• Where will you build it? Away from built up areas or near emergency services?
Prediction, protection and preparation for earthquakes
