By Ethan Banks
11/03/2010
Volcanoes
Volcanoes for dummies
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.
Shield Volcanoes
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.
Layer of ash layers of
lava
Central ventcrater
Cinder Cone VolcanoWhen cinders erupt explosively from a volcano vent,
they pile up around the vent creating a cone shaped hill called a cinder cone volcano.
layers of cinders
crater
Main vent
cinders
CalderaA 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.
extinct magma chamber
Lake in old craterBlown off top
Hot Springs and GeysersA 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. Parkspray of water
Lava pipePool of water
Lava touching waterUnderground
pool
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
Cooled Pahoehoe
Moving Pahoehoe
Cooled aa
Moving aa
Aa volcano