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Volcanoes (vent- the opening in the rock (crater- the bowl shape in the…
Volcanoes
vent- the opening in the rock
crater- the bowl shape in the top of a volcano
pipe- moves the magma to the crater
magma chamber- where all the magma collects underground
side vent- an opening on the side of the volcano
ash cloud- the smoke that comes out of the volcano
lava flow- the lava that runs down the side of the volcano
how do volcanoes form
60 potentially active volcanoes
occur over hot-spots
form at plate boundaries
ring of fire
where do volcanoes form
lava- molten rock that erupts from Earth
lave erupts an divergent plate boundaries
they form along convergent plate boundaries
more than 60% of volcano activity occours
what is a volcano
a volcano is a vent in Earth's crust which melted or molten rock flows
magma- molten rock below the Earth's surface
lava- molten rock above the surface
types of volcanoes
shield volcanos- common along divergent plate boundaries. large with gentle slopes of basaltic lava
composite volcanoes- large steep sided volcanoes that form from explosive eruptions
Cinder Cones- small steep sided volcanoes that erupt gas rich basaltic lava
Volcanic eruptions
volcanic ash- tiny particles of pulverized volcanic rock and glass
viscosity- a liquid's resistance to flow
lava flows are deadly and damaging
predicting volcanic eruptions
moving magma can deform ground shape or change volcano shape
moving magma can cause a series of earthquakes
increase of gas admission
volcanic eruption styles
Quiet erupition
pours out and runs down the side of the volcano
explosive eruption
start with vent blocked
pressure releases at weak points
ash, rock, pyroclastic flows
Mount St. Helens
march 16 100 earthquakes
legends
Pompeii
vacation place for the rich
very advanced city
frequent earthquakes
most buildings were destroyed or damaged
5 miles from the volcano