Earthquakes and volcanoes 3.3: Earthquakes

• Aardrijkskunde
• Middelbare school
• havo
• Leerjaar 3

3.3 Earthquakes

Goals

After studying this section, you will be able to:

- Explain why an earthquake takes place

Describe the effects of earthquakes

What is the effect of two continental plates moving divergently?

1. Horst and graben
2. Mid-oceanic ridge

What is the effect of two continents colliding?

1. Fold mountains
2. Volcanoes
3. Subduction
4. Trench

Divergent

Convergent

Earthquakes

Subduction

Volcano

Transform

What is the difference between oceanic crust and continental crust?

Fold mountains

Earthquakes

Fold mountains

Volcanoes

Earthquakes

Trench

Subduction

Island arcs

Volcanoes

Earthquakes

Trench

Subduction

Volcanoes

Earthquakes

Horst and graben

Fould blocks

Mid oceanic ridge

Volcanoes

Earthquakes

Earthquakes

Earthquakes

Earthquakes

Oceanic

Oceanic

Oceanic

Plate tectonics and its effects

Where in the world do earthquakes mostly happen?

5,8 magnitude on Richters scale. "Can cause a substantial amount of damage. In highest form building get lightly damaged."

Other effects of earthquakes:

- Landslides

- Liquefaction

Indian Ocean 2004

9,1 magnitude on Richters scale.

"A big natural hazard with possible total destroyment within thousands of kilometres."

Tsunami. 230.000 people got killed.

A tsunami in four steps

Water pulls back from the beach followed by a big wave coming back on to land

Tremors causes waves with a speed up to  800km/h

In shallow water the waves slow down and increase in height.

Earthquake(s) in the seabed 

Earthquake

Wave rises due to shallow coast

Wave pushed up by earthquake

Retreat from water on the beach followed by a big wave that crashes back on land