Download Volcanoes

Volcanoes
By: Cody and Jennifer
• When a volcano erupts, it either has a lava
flow or pyroclastic flow
• Magma that flows onto earth’s surface is
called lava, and when it’s underground it is
called magma
• There are four types of lava
o Blocky lava- cool, stiff lava that cannot travel
far
o Pahoehoe- flows slowly, forming glassy surface
with rounded wrinkles
o Aa- lava has a jagged surface
o Pillow lava- forms when lava erupts
underwater
Block lava
Pillow lava
Aa
pahoehoe
• There are three different types of volcanoes;
shield volcano, cinder cone volcano, and
composite volcano
• Shield volcano- built from layers of lava from
repeated nonexplosive eruptions
• Cinder cone volcano- made entirely of
pyroclastic material from explosive eruptions
• Composite volcano- formed by explosive
eruptions of pyroclastic material followed by
quieter outpourings of lava
Volcanoes
Vocabulary Section 1
• Volcano – mountain that forms when magma
is forced to earth’s surface
• Lava – magma that flows onto the earth’s
surface
• Pyroclastic material – consists of rock
fragments created created by explosive
volcanic eruptions
Vocabulary Section 2
• Shield volcano – built out of layers of lava
• Cinder cone volcano – made of pyroclastic
material
• Composite volcano – formed by explosive
eruptions of pyroclastic material followed by
quieter outpourings of lava
• Crater – central vent in volcanoes is a funnelshaped pit
• Caldera – magma chamber empties and it’s
roof collapses
Vocabulary Section 3
• Rift – when the tectonic plates separate, a
deep crack forms between the plates
• Hot spots – places on the earth’s surface that
are directly above columns of rising magma,
which is also called mantle plumes
Summary
So there are three different types of
volcanoes which are shield volcano, cinder
cone volcano, and composite volcano. Craters
are funnel-shaped pits that form around the
central vent of a volcano. Calderas are a large
bowl-shaped depressions formed by a
collapsed magma chamber.