Volcanoes

Nota:

• This mind map supports the study of the earth's surface section of the syllabus and concentrates on volcanoes.

1. Key Words
   1. Magma
   2. Lava
   3. Geyser
   4. Vent
   5. Crater
   6. Ash
   7. Debris
2. Types of Volcanoes
   1. Active
      1. Erupts regularly
      2. Mount Etna
   2. Extinct
      1. Has not erupted for thousands of years
      2. Slemish, Antrim
   3. Dormant
      1. Cotopaxi, Peru
      2. Has not erupted in a long time
3. Formation of a Volcano
   1. 1. Magma reaches the earth's crust through a narrow vent
   2. 2. Pressure builds up in the vent
   3. 3. The volcano erupts, blasting lava, ash and mud into the air
   4. 4. This material collects around the vent and the cone shape forms
   5. 5. Repeated eruptions add to the cone shape mass
4. Positive Effects of Volcanoes
   1. New land is created
   2. Minerals created
   3. Fertility of soil increases
   4. Geysers formed
   5. Dormant and extinct volcanoes are centres for tourism
5. Negative Effects of Volcanoes
   1. Gases from volcanoes can be toxic
   2. Volcanic eruptions can destroy towns and villages and cause death
   3. Volcanic eruptions can generate tidal waves
   4. Eruptions can trigger avalanches