Post on 05-Dec-2014
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What happens during an Earthquake?
Learning Objective: To understand how an earthquake is created, the impacts they cause and how they can be managed
Plate Boundaries/ Margins
Conservative/ Transform Boundary
Destructive/ Convergent Boundary
Constructive/ Divergent Boundary
Which one is the odd one out?
Plate Boundaries/ Margins
Conservative/ Transform Boundary
Destructive/ Convergent Boundary
Constructive/ Divergent Boundary
Volcanoes = destructive & constructiveEarthquake = destructive & conservative
Type of plate margin Description of changes
Earthquake/ volcanic activity
Examples
Destructive (oceanic & continental)
Oceanic crust is forced down & melts
Volcanoes produced by melted oceanic rockEarthquakes produced by rock rising
Nazca & South American plates colliding
Destructive (two continental)
Continental plates pushed upwardsFold mountains
Earthquakes produced Indo-Australian collides with Eurasian = Himalayas
Constructive on land Plates move apart, magma moves to surface
Some volcanic activity, earthquakes along the faults
East African Rift Valley
Constructive under the ocean
Plates move apart Volcanoes occur when magma reaches the surface
Mid Atlantic Ridge
Conservative Plates slide past each other
Earthquakes produced from friction
San Andreas Fault
So how exactly do earthquakes happen?http://www.bbc.co.uk/news/science-environment-12739417
Earthquakes can occur when plates ______
towards each other, or ______ by _____
Normally these plates want to move
___________ at about 9 cm per year
But sometimes they get _______. Now the
energy ______ as the plates continue to
______
Eventually, they _____. All the stored _______
gets __________
The result is an _______________. The plates literally _______ up, displacing a lot of energy into the _____
Extension: how do you think an
earthquake might cause a tsunami?
v
http://www.bbc.co.uk/learningzone/clips/what-causes-earthquakes/14060.html
So how exactly do earthquakes happen?http://www.bbc.co.uk/news/science-environment-12739417
Earthquakes can occur when plates move
towards each other, or side by side.
Normally these plates want to move together at about 9cm per year
But sometimes they get stuck. Now the energy
builds as the plates continue to move
Eventually, they slip. All the stored energy gets
released
The result is an earthquake. The plates
literally flick up, displacing a lot of energy
into the crust
Extension: how do you think an
earthquake might cause a tsunami?
v
So why did Japan experience the huge tsunami this year?
Using the diagram, write clear definitions for ‘epicentre’ and ‘focus’
Focus – the point within the earth’s crust where an earthquake occursEpicentre – the point on the earth’s surface directly above the focus where an earthquake occurs
Which house, 1 or 2, would experience the larger effects from the earthquake? Why?
21
What would happen if the focus was at the red cross instead?
Other effects from earthquakes:Soil liquefaction – what is it?
saturated
groundwater
shaking
upwards
surface
sludge
The effect of liquefaction in New Zealand in February 2011 earthquake
What do you think the secondary effects of
liquefaction are?
Explain why Kobe was particularly suceptible to the effects of liquefaction in 1995
LO: To understand the three main ways to limit the damage from
earthquakes
How do you reduce the damage from Earthquakes?
Key Themes Exam 50%
• Weds 12th June• 29 days away• 15 hours of teaching time
• HOWEVER…. Still got to complete 2 case studies for earthquakes, hurricanes, drought and then 2 hurricane case studies.
• EVERY LESSON IS COMPULSORY• YOU SHOULD BE REVISING – RIVERS AND COASTS
AND ECONOMIC DEVELOPMENT
SDME resit meeting in here tomorrow
lunchtime for 5 minutes
Complete secondary effects
• Add them to your table.
• Come up with 5 and you get a point for every one you match with my list.
• Try linking them with your primary effects.
4-marker questions – explain
When a 4-marker asks you to explain, you need to make 2 descriptive points and explain them.
Example...Explain why some Year 11 students at Carterton CC might choose to go into Sixth Form. (4 marks)
Your turn….• Explain how humans are affected by
earthquakes (4marks).make 2 descriptive points and explain them.
How many marks?Roads get damaged and people cannot get to work.
Roads get damaged and people cannot get around, meaning that their business might lose money until the roads are repaired.
As water pipes burst, people cannot get fresh drinking water, so they have to buy bottled water, which might be expensive or run out.
Roads get damaged and people can’t go to work and they have no clean drinking water because pipes burst.
Predict – Use technology to warn people a hazard is
comingProtect – Put measures in place to reduce the threat of a
hazardPrepare – Get ready for the arrival of a hazard
Definitions...
Quick Definitions
• Predict – say when a hazard is coming• Protect – put protection in place• Prepare – get ready
Extension: can you think of an example of each of these for earthquake hazards?
Predict, Prepare or Protect?
Making sure people are ready for when an earthquake hits e.g. Earthquake drills
Designing earthquake proof buildings
Monitoring ground movements to see when an earthquake might hit
Extension: which one do you think is the best idea for a city that often gets earthquakes? Why?
PREPARE PROTECT
PREDICT
Earthquake definition
“A sudden and violent shaking of the ground, sometimes causing great destruction, as a result of movements within the earth's crust or volcanic action.”
How would you go about predicting an earthquake?
Knowing when the quake will arrive keeps getting easier in Japan. Official earthquake warnings that pop up in a window on your computer screen is the latest alert method. Already earthquake warnings are broadcast on TV. Cable TV providers and telecoms offer official earthquake warning emails to cellphones and computers. A cable TV company sells an earthquake warning receiver. A digital cordless phone knows a tremor is on the way.
http://www.youtube.com/watch?v=24KfBwkMw_M
Japan: an earthquake-proof country?
Watch the clip about earthquake proof buildings in JapanWhat have they added to the hotel to make it earthquake proof?
What have these architects added to the Akashi Kaikyō suspension bridge in Japan?How did it change during the earthquake??
http://www.youtube.com/watch?v=BpCjGiQqjRM
Earthquake proof buildings (retrofitting)
• What parts of the building do you think make it aseismic (posh word for earthquake proof!)
• Make a sketch of the building and label on the parts
• Page 146
Homework: Due next Friday• Write a short paragraph to answer the
question:“Is Japan ready for the next big quake?”
• Use your own research• Think about the 3 Ps!