Download Three basic types of volcanoes

When Volcanoes Erupt PG. 107
Volcano

a break/hole on the crust of
Earth that emits lava, ash, and
gases. (usually forms a
mountain)
What’s inside a volcano?
Crater The central
funnel shaped vent at
the top of a volcano
Vent—an opening at
the surface of the Earth
through which volcanic
material passes
Magma Chamber—the
body of molten rock
that feeds a volcano
Magma Chamber
What are nonexplosive eruptions?
Volcanoes that
erupt only lava and
gas
The most
common type of
eruption
What erupts
from a volcano?
1. Lava-- 4 types
Pahoehoe
Low viscosityflows quickly,
smooth glassy
surface
A’a—high viscosity- flows
slowly, brittle jagged surface
Pillow lava—lava
that erupts under
water
Blocky lava—sharp edged
chunks of stiff lava
What are explosive
eruptions?
Clouds of hot rock,
ash and gas rapidly
shoot out from the
volcano
Millions of tons blast out
in a few seconds
2. Pyroclastic material
4 types of material
Bombs—large blobs of
magma that harden when
they fly through the air
Blocks—largest pieces of
solid rock blown away
from the volcano
4. Volcanic ash–
magma explodes
into tiny glass like
slivers
3. Lapilli—little
stones of magma
that harden before
they hit the ground
What are pyroclastic
flows?
Enormous amounts of
hot ash, dust and gas
are ejected from a
volcano
Races downhill at
more than 200 km / hr
Temperatures can
exceed 700 degrees C
What are the effects of
volcanic eruptions?
Climate can be
changed as ash
and gas spread
throughout the
atmosphere
Eruptions can
affect the
whole Earth
with lower
temperatures
Other effects…
Lava can be very
destructive—it’s
very hard to stop
Pyroclastic materials
(ash and rock)
can travel at high speeds
and can be deadly
Mt. Vesuvius and Pompeii
Mt. Vesuvius and Pompeii
What are other types of
Volcanic Landforms?
A
3 types
1. Lava Lakeslarge amounts of
molten lava
contained in a
depression
2. Calderas
A semicircular
depression that forms
when the magma
chamber partly
empties and causes
the ground above to
sink
Many times
larger than a
crater
3. Lava Plateaus
A wide flat area
caused by repeated
nonexplosive
eruptions of lava
that spread over a
large area