Volcano Study Guide
November 21
• 1.
–
• molten rock that has
reached the surface of
the earth
• 2.
–
• molten rock within the
earth
VENT
HOT SPOT/ ASH
• 5.
–
• a localized zone of
melting in the mantle
that is fixed under a
plate
• 6.
–
• fragmented volcanic
material with particles
that measure less than
2 mm in diameter
• ov
LAVA
CRATER
• 9.
–
• a small, bowl-shaped
hole that forms when
rock explodes from a
volcano during an
eruption
• 10.
–
• pebble-sized pieces of
congealed (hardened)
lava and rock fragments
• 11. What is the
difference between
magma and lava?
• Magma is molten rock
beneath the earth’s
surface, and lava is
molten rock on the
earth’s surface.
VISCOSITY
• 12. Which lava is more
viscous: slow-moving lava
or runny lava? Name one
other liquid that you
consider to be very
viscous.
• Slow-moving lava is more
viscous.
• Corn syrup would be very
viscous.
13. Describe how
each volcano
type forms and
what it looks like.
Include a sketch.
a. It forms from
alternating
eruptions of
viscous lava and
ash. It is tall and
steep near the
summit.
b.
It forms when
cinders
accumulate
around a
volcanic vent. It
is small and cone
shaped.
c.
It forms
from
eruptions of
runny lava. It
is wide and
broadly
sloping.
• 14. How does the heat
content of a substance
affect the way it flows?
• Heating a liquid causes
it to be less viscous
(more runny).
DESTRUCTION
• 15. What are some of the
destructive (bad) effects of
volcanoes? Give at least 2.
• Volcanic ash can cause
suffocation, contaminate water
supplies, and collapse roofs.
• Earthquakes, flash floods,
rockfalls, and mudflows.
• Eruptions can cause tsunamis.
• Eruptions can destroy homes and
cause death.
• 17. What causes
earthquakes to
occur before a
volcano erupts?
• The force of
moving magma
pushing upward
causes colder rock
around the
magma to break
and shift.
RISING MAGMA…FLOWING
LAVA
• 19. Describe how rising magma and flowing lava can create the
following;
• a. New land or rock
• When molten rock cools, it hardens into new rock/land.
• b. Volcanic Islands
• Over time, the buildup of cooled magma that erupts under wat
• er can create volcanic islands.
• c. Underwater pillow lava
• Hot magma erupts onto the cold ocean floor and immediately cools
in the water.
• d. Bulges in the earth’s surface
• Magma under the earth’s surface rises and pushes upward on the
overlying rock.
• 20. What are some of the ways volcanologists predict
volcanoes?
• Scientists look for the following changes in a volcano:
emission of sulfur dioxide gas, growth of lava domes,
increased seismic activity, cracks in the earth, steam
and ash clouds.
• 21. Describe how
• each type of rock
forms.
• a. Igneous rock –
• It forms when magma
or lava cools and
crystallizes on or below
Sedimentary
rock –
b.
It forms from compacted
• C.
• It forms
when any
rock type is
changed by
the earth’s
high
temperature
and pressure.
Parts of a Volcano