Chapter 3: Earthquakes and volcanoes

• Aardrijkskunde
• Middelbare school
• havo, vwo
• Leerjaar 1

Chapter 3: Earthquakes and volcanoes

Section 3.1.: Layers and plates
Section 3.2.: Plate movements
Section 3.3.: Earthquakes
Section 3.4.: Effects of earthquakes
Section 3.5.: Volcanoes
Section 3.6.: Living close to a volcano

Section 3.1.
The earth's layers and plates

Learning goals:
1. Describe how the earth’s layers fit together. 

2. Describe what tectonic plates and tectonic plate boundaries are. 

3. Describe the movements of plate tectonics in the past. (VWO)

The earth seems to be one solid sphere, but if you look more closely you'll notice that the earths crust moves very slowly. 

These movements are caused by the inner structure of the earth.

Layers of the earth

Mantle: thickest layer of the earth, solid but also moveable.

Crust: layer we live on, solid and very thin. Made of rocks.
 

Layers of the earth

Inner core: solid made out of nickel and iron. Very warm (4000 and 6000 degrees C.)

Outer core: liquid also made out of nickel and iron. Cooler around 3000 - 4500 degrees C.
 

Plate tectonics

The earth consists of tectonic plates, these plates moves in a process we call plate tectonics or continental drift.

These movements cause earthquakes.
Some plates are small (e.g. Carribbean Plate) others are huge (e.g. Eurasian plate).

Basalt

Granite

We have two types of tectonic plates:

Oceanic plates:

Found under oceans, thin (up to 10 kilometres) but heavier. Made of basalt.

Continental plates:
Found under continents, thick (up to 75 kilometres) but lighter. 
Made of granite.

Plate tectonics is nothing new.

   

The earth's history is filled with plate movements, 300 million years ago all the plates formed one huge supercontinent called Pangea.

Section 3.2.
The earth's layers and plates
Learning goals:
1. Describe in which direction the tectonic plates move. 

2. Expain why earth’s tectonic plates move 

3. Describe the effect of the three plate movements 

4. Describe the ridge-push and slab pull mechanisms

The earth seems to be one solid sphere, but if you look more closely you'll notice that the earths crust moves very slowly. 

These movements are caused by the inner structure of the earth.

Effects of the convection current

Three different plate movements

• Plates move away from each other = divergent movement
• Plates move toward each other = convergent movement
• Plates slide alongside each other = transform movement

Make a list with the three plate movements and write behind each plate movement the effect the plate movement has. 

Use pages 57 - 60 

in your text book.

Divergent plate movement:

e.g. earthquakes

Convergent plate movement:

e.g. earthquakes

Transform plate movement:

e.g. earthquakes

What is the difference between magma and lava?

Section 3.3.
Earthquakes

Learning goals:
1. Explain why an earthquake takes place 

2. Describe the effect of earthquakes 

3. Describe the effect of tsunamis

4. Explain how earthquakes in the Netherlands occur 

Most heavy earthquakes take place near plate boundaries. And especially plates that move convergent or slide along each other.

https:

Richter scale

We express the intensity or magnitude of an earthquake on the so called Richter scale.  

We measure earthquakes with a machine called a seismograph. 

Read the first paragraph on page 62.
What's the difference between the hypocentre and epicentre of an earthquake?

An earthquakes has direct but also indirect effects. Name examples of these.

When an earthquake occurs on sea it can cause a tsunami.  

A tsunami killed thousands of people in 2004 and 2011. 

Most large earthquakes happen on plate boundaries and are caused by the movement of tectonic plates.

Mercalli

To measure the effects of earthquake we use the Mercalli scale. 

Earthquakes in the Netherlands.

Sometimes also the Netherlands are hit by an earthquake, but these have a lower magnitude.

1. In South-Limburg these earthquakes happen because of smaller faults in the plate.

2. Because of the production of natural gas in Groningen.

https:

Section 3.4.
Comparing the effects of earthquakes

Learning goals:
1. Compare the effects of earthquakes in LEDCs and MEDCs 

2. Explain why the effects of earthquakes vary between LEDCs and MEDCs 

The effects of earthquakes are different in LEDC's then in MEDC's.

LEDC = less economical developed country

MEDC = more economically developed country

LEDC

More casualties and deaths but less economic damage

MEDC

Less casualties and deaths but more economic damage

Nowadays it's easier to predict some natural disasters.

To minimalize the effects of natural disasters we use hazard management. 

This deals about preventing casualties by e.g. evacuation plans or use modern building technology.

Section 3.5.
Volcanoes

Learning goals:
1. Describe what happens during a volcanic eruption

2. Explain what the effects of volcanic eruptions are

3. Describe three different types of volcanoes (shield, composite and hot spot) 

Not all the volcanoes are the same. In this section we discuss three different types of volcanoes.

If the magma comes out of the volcano during a eruption it is called lava.

Composite volcano

Shield volcano

Hot-spot volcano

Make a list with all the keywords in section 3.5. and write the correct definition behind the keywords.

Where do we find the different types of volcanoes?

Which volcanoes have the heaviest eruptions and why?

Section 3.6.
Living close to a volcano

Learning goals:
1. Describe what the benefits of volcanoes are  

2. Explain why the benefits differ between LEDCs and MEDCs

Living near a volcano can be very dangerous, although some people decide to live in these places.

Make a list of positive factors of living near a volcano.