1.3 Volcanism (part 1)

• Aardrijkskunde
• Middelbare school
• havo, vwo
• Leerjaar 2

1.3: Volcanoes - part 3

This lesson

• Explanation 1.3 
• Videoclip
• Working for yourself (test preparation) 

Learning goals

1. You know what a volcano is and what the consequences of volcanic eruptions can be
   
2. You know the different types of volcanoes 
3. You can point out the regions with volcanic activity on a map showing the tectonic plates

Where do volcanoes form?

• Convergent plate borders (colliding)
  
• Divergent plate borders (spreading)
  

Ring of fire

How do volcanoes form?

1. Convergent movement (subduction zone) > oceanic plate and continental plate > stratovolcano 
2. Divergent movement > oceanic plate and oceanic plate > shield volcano 
   
3. Hotspots > shield volcano 

1: Subduction zone 

(volcanoes on land)

A volcano is formed by a series of eruptions of lava and ash

1.  Ocean floor is pushed into mantel
   
2.  Rock melts, magma is formed
   
3.  Heated substance lighter than surroundings
   
4.  Heated substance wants to rise
   
5.  Pressure too high: eruption
   
6.  Magma becomes lava and leaves volcano via the crater
   

Stratovolcano 

• Convergent movement 
  
• Oceanic plate and continental plate 
  
• Subduction zone 
  

Stratovolcano 

Stratovolcano 

• Explosive 
  
• Steep slopes
  
• Subduction zone

2: divergent movement (volcanoes in the ocean)

1.  Two parts of ocean floor move apart
   
2.  Crack in the Earth’s crust
   
3.  Filled with hot rock (lava)
   
4.  Lava comes into contact with water
   
5.  Lava solidifies
   
6.  A new piece of ocean floor is formed
   
7.  Mid-ocean ridge = sort of stretched out mountain range along the ocean floor
   

Mid oceanic ridge

• Divergent movement
  
• Oceanic and oceanic plate
  

Volcanoes in the oceans can become volcanic islands 

Shield volcano

• Effusive (niet explosief) 
  
• Flat slopes (vlakke hellingen)
• Divergent movement and hotspots 

How are volcanoes formed?

Bron: BuiteNLand HA1

3: Hotspot

• Burns through earth's crust and forms volcano
  
• Earth's crust slides over hotspot, volcano "floats" onward
  
• Shield volcano
  

Point out the regions with volcanic activity on the map

How do volcanoes form?

1. Convergent movement > oceanic plate and continental plate > stratovolcano 
2. Divergent movement > oceanic plate and oceanic plate > shield volcano 
   
3. Hotspots > shield volcano 

This lesson

• Explanation 1.3 
• Working for yourself (test preparation) 

Working for yourself

• Make a summary
  
• Worksheet
  
• Oefentoets
  
• Videoclips
  
• Extra explanation 
  

Preparation test: 1.1 and 1.2