Earthquakes and why they happen

Section	Detail
Key Ideas	Earthquake strength is measured on the Richter Scale and the intensity of their effects on the Mercalli Scale. Earthquakes happen because of the stress where tectonic plates meet.
Terms	Distribution, Richter Scale, seismograph, Mercalli Scale, focus, shock waves, epicentre.
Starter	BBC Earthquakes Video
Main	1. TDIT    2. Using H p18 answer the following questions:    What are earthquakes?    How dangerous are they?    How many earthquakes are there each year?    Where do they occur (what is their distribution or global pattern)?    What is the link with where volcanoes occur?    3. What is the difference between a seismometer and a seismograph?    4. What do the Richter and Mercalli scales measure?    5. Explain how an earthquake measuring 6 on the Richter scale is 100 times stronger than one measuring 4.    6. What number on the Mercalli scale is an earthquake likely to be if it is the top story on the BBC news? Does this depend on the country the earthquake occurs in?    7. On what type of plate boundary do most earthquakes happen? Explain why many strong earthquakes occur along destructive plate margins.    8. Why are tectonic stresses lower along constructive plate boundaries?    9. Draw a diagram to illustrate the terms; focus, shock waves, and epicentre.    10. Read eyewitness accounts of earthquake survivers http://www.bbc.co.uk/news/world-asia-pacific-12711152 http://www.geography-site.co.uk/pages/physical/earth/witness/cal1.html http://news.bbc.co.uk/1/hi/8455735.stm
Plenary	Run through 'Earth shakes, rattles and rolls' powerpoint.

BBC Earthquakes Video - Starter

Earth shakes rattles_and_rolls

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Why is the earth's crust unstable?

Section	Detail
Key Ideas	The earth's crust is unstable, especially at plate boundaries. There are differences between oceanic and continental plates.
Terms	crust, plate, plate boundary/margin, mantle, convection currents
Starter	Apple. NT p8 A
Main	1.   TDIT. 2.   Students draw cross-section of earth and annotate with Key Terms. 3.   Pack of cards/plates simile. 4.   Students examine examples of basalt and granite for differences between oceanic and continental crust (physical and/or videos below). 5.   Students draw diagram NT p9 B 6.   NT p9 Qus 2b
Plenary	a.   What are the two types of plate called? b.   Give one difference between them. c.   What is the name for where plates meet? d.   What causes the plates to move?

Granite

Basalt