By Ethan Banks
11/03/2010
Volcanoes
Shield Volcanoes
A shield volcano is a broad, gently sloping,
volcano where gently flowing lava hardens and
gradually builds up. This is the shield volcano
Mauna Loa in Hawaii.
Side vent
crater
Main
chamber
Lava flow
Composite Volcano
Layers of lava alternate ash, cinders, and bombs, to
make up a composite volcano which has both quiet
and explosive eruptions.
crater
Central vent
Layer of
ash
layers of lava
Cinder Cone Volcano
When cinders erupt explosively from a volcano vent, they pile up
around the vent creating a cone shaped hill called a cinder cone
volcano.
crater
cinders
Main vent
layers of cinders
Caldera
A caldera is a volcano that has blown all of its
contents becomes a hollow shell. One of the
biggest calderas is Crater Lake in Oregon.
Lake in old crater
extinct magma
chamber
Blown off
top
Hot Springs and Geysers
A hot spring is where ground-water has been heated inside a
pool. A geyser is where water trapped underground sprays from
underground. The most famous geyser is “Old Faithful” in
Yellowstone Nat. Park
spray of water
Pool of water
Lava pipe
Underground
pool
Lava
touching
water
Extra, extra, extra!
Did you know that there are two different kinds of lava? The two
kinds are, Pahoehoe ( pah hoh ee hoh ee ) and aa (ah ah).
Pahoehoe is a runny, thin lava that flows easily. Aa is cooler, slow
moving lava that hardens into huge chunks.
Pahoehoe
volcano
Aa volcano
Cooled
Pahoehoe
Cooled aa
Moving aa
Moving
Pahoehoe