Download VOLCANIC ERUPTIONS

VOLCANIC ERUPTIONS
Inside a Volcano
• Magma Chamber- A pocket of collected
magma beneath a volcano.
• Pipe- A long tube in the ground that
connects the magma chamber to Earth’s
surface.
• Vent- An opening where gas and molten rock
leave the volcano.
• Lava Flow- The area covered by lava as it pours
out of a vent.
• Crater- A bowl shaped area that may form at the
top of a volcano around the central vent.
• Pyroclastic Flow - Occurs when an explosive
eruption hurls out a mixture of hot gases, ash,
cinders, and bombs.
When a volcano erupts, the force of the
expanding gases pushes magma from the
magma chamber through the pipe until it
flows or explodes out of the vent.
Types of Eruptions (2 types)
• Quiet
– A volcano
erupts quietly if
its magma is
LOW in silica.
– Thin magma
that flows
easily
• Explosive
– A volcano erupts
explosively if the
magma is HIGH
in silica.
– Thick and sticky
magma.
– Clogs volcano’s
pipe and creates
more pressure.
Volcano Life Cycles
• Active: Also known as “live”… A volcano that
is erupting or showing signs that it will erupt in
the near future.
• Dormant: Also known as “sleeping”…A
volcano that is not currently active, but may
become active in the future.
• Extinct: Also known as “dead”… A volcano
that is unlikely to erupt again.