Les 7 - Samenvattingsles

• Aardrijkskunde
• Middelbare school
• vwo
• Leerjaar 2

Summary

I will summarize the things you need to know for the test!

Learning goals

• which layers the earth is made of
  
• that movement of the mantle causes the crust to break and move as well
  
• How the earth used to have a supercontinent
  

Learning goals

• You know that plates move
  
• You understand that colliding plates can lead to the formation of mountains, earthquakes, tsunami's and volcanoes
  
• You can point to areas on a map which are most likely to have earthquakes, volcanoes, tsunami's and mountain formation

Key words - 1.1

Three layers of the earth

1. Core: the centre of the earth
2. Mantle: Slowmoving magma between the crust and the core
3. Crust: The thin outer layer of the earth

Plate - A piece of the earths crust

Plate tectonics - Movement of the earths crust

Supercontinent - This is what it is called when all plates moved together to form one giant continent

Convection current (convectie stroming) - syrupy material that flows very slowly and makes the crust move. 

Plate tectonics

The movement of the earth's crust

• This leads to formation of mountains
  
• Volcanism
  
• Earthquakes
  

Plate boundaries

• Some move towards each other 

(Convergent)

• Others move away from each other
  

(Divergent)

• Others move alongside each other

(Transform)

3 types of convergent plate boundaries

• Oceanic - continental boundary
  
• Oceanic - oceanic boundary
  
• Continental - continental boundary
  

Oceanic - oceanic boundary

• Same story
  
• Heaviest plate subducts -> Rule: Older = heavier
  
• Mountains and volcanoes form under water
  

Continental - continental boundary

Less subduction -> less vulcanism

High mountains form -> for instance Himalaya

Fold mountains

Oceanic - continental boundary

• The heavy oceanic plate dives under the lighter continental plate, a process called subduction (subductie)
  
• The collision can form mountains
  
• The melting of the oceanic plate causes vulcanism
  

Key words §1.2

Earthquake - Vibration caused by a sudden movement of the earths crust

Epicentre - The point on the earths crust where the earthquake is the strongest

Magnitude - The power of an earthquake measured on the Richter scale

Richter scale - Scale used to measure the magnitude of an earthquake

Plate tectonics - movement of the earths crust

Learning goals

1. You know what an earthquake is and what the consequences can be.
2. You understand how earthquakes form

Earthquake

• Vibration caused by a sudden movement of the earths crust
• Why is it sudden?
• A little experiment

Plate boundaries

• Some move towards each other 

(Convergent)

• Others move away from each other
  

(Divergent)

• Others move alongside each other

(Transform)

Where do earthquakes form?

Convergent plates -> Heaviest earthquakes

Transform plates -> Heavy earthquakes

Divergent plates -> Mild earthquakes

Key words §1.3

Magma - Liquid rock in the earths mantle

Lava - Liquid rock from the earths mantle that comes out of the crater of a volcano

Crater - The place where magma flows out a volcano and turns into lava

Volcano - Place where liquid magma flows out from the earths mantle

Mid-ocean ridge - A place in the middle of an ocean where plates move apart and magma comes flowing out.

Stratovolcano - Coneshaped volcano with thick lava and explosive eruptions

Shieldvolcano - Relatively flat volcano with thinner lava and effusive eruptions

Learning objectives

1. You know what a volcano is and what the consequences of volcanic eruptions can be
2. You understand how, and where volcanoes are formed 
3. You understand why the consequences for people in poor countries differ from the consequences for people in rich countries.

learning objectives

• You understand the difference between a shield volcano and a stratovolcano
• You understand how these volcanoes are formed
• You know the difference between explosive and effusive eruptions

Mid-ocean ridge

This type of volcano froms when two oceanic plates move away from each other. This is what we call divergent plate movement. These volcanoes are usually quite calm, because the lava flowing out is not blocked by anything.

Magma

The liquid rock in the mantle is called magma

Subduction

Subduction happens when an oceanic plate dives below another plate. The plate that dives into the mantle melts and causes magma to start flowing up. This is what causes vulcanism.

Lava

As soon as the magma is outside the volcano it is called lava. 

Volcano

This is a volcano. A coneshaped mountain that can erupt and can have lava flowing out. When a volcano is formed by subduction the eruptions can be explosive, because the crater can get blocked by lava solidifying (stollen) in the crater.

Crater

The place where the magma leaves the volcano is called the crater

Trench

Depression of the sea floor. Occurs at subduction zones. Some trenches can be extremly deep. The Mariana Trench in Asia is at points 11 km deep.  That means that the Mount Everest could fit inside the Mariana Trench with more than 2 kilometers to spare.

Reasons to live near a volcano

1. A good place for generating geo-thermal energy

Reasons to live near a volcano

1. A good place for generating geo-thermal energy
2. The ground is fertile

Reasons to live near a volcano

1. A good place for generating geo-thermal energy
2. The ground is fertile
3. It is good for tourism

Reasons to live near a volcano

1. A good place for generating geo-thermal energy
2. The ground is fertile
3. It is good for tourism
4. Cultural reasons
5. lack of money for moving

Consequences of volcanic eruptions

• Ash clouds
• lavastreams
• Debris being tossed around
• Pyroclasic flow

Consequences of volcanic eruptions

• Ash clouds
• lavastreams
• Debris being tossed around
• Pyroclasic flow

Consequences of volcanic eruptions

• Ash clouds
• lavastreams
• Debris being tossed around
• Pyroclasic flow

Different volcanoes

Video 1: Stratovolcano

cone shaped

Thick lava

Dangerous eruptions, explosive

Video 2: Shieldvolcano

Flat volcano

Thin lava

People can come close, effusive

Different eruptions

Thick lava

Closed crater -> Explosive eruption

High cone shaped volcano

Thin lava

Open crater -> Effusive eruption

relatively flat volcano

Learning objectives §1.4

• You know what a tsunami is
• You know how a tsunami becomes as big as it does
• You know why a tsunami affects people in poor countries different from people in rich countries

Key words §1.4

• Trench (trog) – Depression of the sea floor. Occurs at subduction zones. 
• Tsunami (tsunami) – Big tidal wave that forms due to an earthquake at the bottom of the sea.

Tsunami creation 101

On the ocean the wave is low, but long and fast. Like this car.

Tsunami creation 101

Once it hits the shore the wave slows down rapidly at the front. Just like this car crashing into it.

Tsunami creation 101

The back of the car, however, is still moving quite fast.

Tsunami creation 101

This causes a massive tidal wave

or crash in the case of the car