A brief overview of the different types of volcano and their characteristics (including examples)

1. Volcano Types
By Ella MacColl

2. Hot Spots
These are volcanoes which do not form at
plate margins but in the middle of plates, such
as the chain of volcanic islands in Hawaii in
the Pacific.
It is thought that these occurred due to a
localised hot spot.
This interplate volcanic activity is caused by
unusually hot mantle material forming in the
lower mantle, pushing it’s way into the upper
mantle to form a magma plume.
This magma plume pushes through the
lithosphere above, when the lava breaks
through the surface, active volcanoes form.
Magma plumes are stationary, so as the plate
moves over the top of it, a line of volcanoes is
created – such as the Hawaiian Ridge a top
the pacific plate. The Volcano above the hot
spot is active and the others remain dormant.

3. Dome Volcanoes
Often occur at destructive plate margins.
The lava from dome volcanoes tends to
be either rhyolitic or andesitic.
CHARACTERISTICS:
o Made up of layers of lava
o Steep sided - high viscosity lava (flows
slowly)
Similar to Stratovolcanos – except a
stratovolcano has alternating layers of
ash and lava.

4. Caldera
Often occur at destructive margins,
where they produce andesitic and
rhyolitic lavas. Formed when central
part of volcano has collapsed or blasted
off as magma chamber has emptied.
CHARACTERISTICS:
• Very wide circular crater – several
kilometres across.
Eg. Aira Caldera - Japan

5. Shield Volcano
Often occur at constructive margins or
hotspots. Usually produce basaltic lava.
CHARACTERISTICS:
• Gentle Sloping Sides – Caused by
low viscosity lava (flows over long
distances)
Eg. Mauna Loa - Hawaii

6. Fissure Volcano
AKA – Fissure Vent or Volcanic Fissure
Occur at constructive margins where plates
move apart allowing magma to erupt onto the
earths surface. Usually produce basaltic lava.
CHARACTERISTICS:
• Fairly flat surface – Low viscosity lava (flows
over long distances)
• Long linear vent – can be a few metres wide
but several kilometres long
Eg. Laki- Iceland