EarthquakesBy the end of this lesson you should be able to:

Describe what earthquakes are Explain what causes earthquakes Describe the ways in which earthquakes can be measured

Some of you will be able to: Explain the geographical location of earthquakes Evaluate the scales of measurement

What are they doing and why?

∗ Sudden and violent movement or fracture within the earth followed by the series of shocks resulting from the fracture

What are earthquakes?

Where do they happen and why?Which plate boundaries are they

associated with?

Can you name the plate boundaries?

Earthquakes can occur at the 4 main plate boundaries but the most powerful earthquakes are normally at and boundaries.

CONSERVATIVEDESTRUCTIVE

CONSERVATIVE

DESTRUCTIVE

∗ Using a flow diagram to explain how an earthquake happens

Plate boundaries, destructive, conservative, convection currents, friction, pressure, slips,

fault line

What causes earthquakes?

∗ The focus is a place underground where the rock slips

∗ Epicentre is the place directly above the focus on the surface

∗ The released energy travels outwards as shockwaves called seismic waves

∗ These waves lose energy as they pass through the crust so damage is less as you travel away from the epicentre

Where does it happen? Label the diagram

∗ How can we measure earthquakes?

∗ There are two scales we can use can you name either?

Measuring earthquakes

∗ Using page 207 look at the Richter Scale I want you to:

1. Describe how the scale is used to measure earthquakes?

2. How large is the scale?3. Evaluate how useful you think it is? What are

the negatives of using it?

Measuring earthquakes

Measuring Earthquakes

∗ Primary effects are the immediate effects caused directly by the earthquake. These include:

∗ Damage or collapse buildings∗ Damage to other infrastructure (e.g. roads,

bridges, railway lines)∗ Falling objects (signs or glass from buildings)∗ Injury or death to Human Life

The effects of earthquakes

∗ Secondary effects are indirect effects and problems faced after an earthquake. These include:

∗ Fires (caused by burst gas pipes)∗ Lack of food and water∗ Spread of disease (cholera and typhoid)∗ Tsunami (huge waves of up to 30 meters high

and travelling up to 500km hour)

The effects of earthquakes

∗ Discuss with a partner the following photographs taken after an earthquake and decide what effects they are trying to show.

∗ Then decide whether this effect is primary or secondary.

Task

Effect shown Primary Secondary1. Fire

2. Collapse buildings

3. Collapse bridge

4. Damaged railway line

5. Tsunami

6. Falling objects

7. Communication lines stopped8. Disease

1. Fire 2. Collapse buildings

3. Collapse bridge 4. Damaged railway line

5. Tsunami 6. Falling objects

7. Communication lines stopped 8. Spread of disease

Effect shown Primary Secondary1. Fire X2. Collapse buildings X3. Collapse bridge X4. Damaged railway line X5. Tsunami X6. Falling objects X7. Communication lines stopped X8. Disease X

Where?

∗ 5:46am 17th January 1995 an earthquake measuring 7.2 on the Richter scale occurred

∗ The focus of the earthquake was 20km SW of Kobe

Kobe, Japan

∗ Using the information on the page 270-271 I want you to write a news report for Sky News

∗ This broadcast is going out a year after the earthquake to mark the one year anniversary of the quake

∗ You must include:∗ Key details of the earthquake∗ What the effects (primary and secondary) were∗ How did they respond initially (short term)∗ What has happened since

So what happened?

Kobe: one year on

Good morning this is …… reporting live from Kobe on the one year anniversary of the disastrous earthquake which caused this city to come to a stand still. One year ago today ...

∗ Research the Haiti earthquake and find out:∗ What happened∗ What were the effects (primary and secondary)∗ How did they respond (short-term and long-

term)

Homework