11.2.2

The Development of Volcanoes

Test yourself on The Development of Volcanoes

Test your knowledge with free interactive questions on Seneca — used by over 10 million students.

Volcanoes

A volcano is an opening in the Earth's crust that is formed when magma rises from inside the earth and erupts onto the surface. Volcanoes can be formed at constructive and destructive plate margins.

Destructive plate margins

Destructive plate margins

  • The denser oceanic plate is forced under the continental plate at destructive margins.
  • The friction and pressure cause cracks (vents) to form in the continental plate. The magma rises to the surface of the Earth through the cracks in the continental plate.
  • This usually creates highly explosive volcanoes (e.g. Mount Vesuvius in Italy) that produce a lot of gas and lava (magma above the surface).
Constructive plate margins

Constructive plate margins

  • At constructive plate margins:
    • Tectonic plates move apart (diverge) because the convection currents in the mantle diverge, creating outward pressure.
  • Magma bubbles up to fill the gap between the plates, creating a volcano.
  • This kind of volcano is common in Iceland.
Hotspots

Hotspots

  • Hotspots do not happen at plate boundaries. But they still count as volcanic activity.
  • Hotspots happen on parts of the Earth's crust over hotter parts of the Earth's mantle.
  • The rising hot air weakens the Earth's crust and magma can reach the surface, bubbling up through the weakness in the crust.
  • The Hawaiian islands all formed as a result of a mid-Pacific hotspot.

The Stages of Volcano Development

Volcanoes exist in one of the following three different states:

Active volcanoes

Active volcanoes

  • Active volcanoes are volcanoes that have a high likelihood of erupting.
Dormant volcanoes

Dormant volcanoes

  • Dormant volcanoes are volcanoes that have the potential to become active but have not actually erupted for at least 10,000 years.
Extinct volcanoes

Extinct volcanoes

  • Extinct volcanoes are volcanoes that are unlikely to ever erupt again and have not erupted for at least 1,000,000 years.
Jump to other topics
1

Geography Skills

2

Geology of the UK

3

Geography of the World

4

Development

5

Weather & Climate

6

The World of Work

7

Natural Resources

8

Rivers

9

Coasts

10

Glaciers

11

Tectonics

12

Climate Change

13

Global Population & Inequality

14

Urbanisation

15

Ecosystems

16

Life in an Emerging Country

17

Analysis of Africa

18

Analysis of India

19

Analysis of the Middle East

20

Analysis of Bangladesh

21

Analysis of Russia

Practice questions on The Development of Volcanoes

Can you answer these? Test yourself with free interactive practice on Seneca — used by over 10 million students.

  1. 1
  2. 2
  3. 3
  4. 4
  5. 5
Answer all questions on The Development of Volcanoes

Unlock your full potential with Seneca Premium

  • Unlimited access to 10,000+ open-ended exam questions

  • Mini-mock exams based on your study history

  • Unlock 800+ premium courses & e-books

Get started with Seneca Premium