1. Prepare for a shock! Aim: To discover what causes earthquakes and how they are measured. Resources p.108-109 Geog.1 Richer Scale Outline

3. How do they happen? Two plates try to SLIDE past one another. Over hundreds of years the friction builds up and then BANG, the pressure is released and the plates JOLT past one another. This causes an earthquake. Epicentre – The place directly above the focus where the quake is felt Focus is the point underground where the plates slip See b/works slide 6 for animation

4. Alaska, 1964

5. How are they measured? Magni tude Richter Number Relative Intensity Low Less than 2.0 Barely felt, minimal or no damage. Moder ate 2.0 to 4.4 Noticeable, damage to buildings, sidewalks, weak structures. Strong4.5 to 7.0Heavy shaking, falling walls and bridges. Very strong Greater than 7.0 Massive shaking, ground moving, landslides, great damage to structures. Liquefaction ****Seismographs measure the strength of the quake****

7. The three types of earthquake - Extension Work - Using page 3 of your booklet, explain with illustrations the three different types of earthquake. Homework: Find out if we have ever had an earthquake in France. When was the last one and where was the epicentre? Use Google images or visit the library. Marked /10 S