Download Effects of Volcanic Eruptions

•
Effects of Volcanic Eruptions
Objectives
Explain how
volcanic eruptions
can affect climate.
• Compare craters,
calderas, and lava
plateaus.
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I. Volcanic Eruptions and Climate
Change
A. Change in Temperature As volcanic ash and
gases spread throughout the atmosphere, they
can block enough sunlight to cause global
temperatures to drop. Such a change in
temperature can disrupt climates all over the
world.
II. Different Types of Volcanoes
A. Volcanic eruptions can cause profound
changes in climate, but the changes to the
Earth’s surface are more familiar.
B. Perhaps the best known of all volcanic
landforms are the volcanoes themselves.
II. Different Types of Volcanoes
C. There are three basic types of
volcanoes:
II. Different Types of Volcanoes
D. Shield volcanoes are built of layers of
lava that are released from repeated
nonexplosive eruptions. The lava spreads
out over a wide area, creating a volcano with
gently sloping sides.
II. Different Types of Volcanoes
E. Cinder cone volcanoes are made of
pyroclastic material usually produced from
moderately explosive eruptions. The
pyroclastic material forms steep slopes.
II. Different Types of Volcanoes
F. Composite volcanoes are formed from
explosive eruptions of pyroclastic material,
followed by quieter flows of lava. These
formations, among the most common types
of volcanoes, have broad bases and sides
that get steeper toward the top.
III. Other Types of Volcanic
Landforms
A. Craters Around the
central vent at the top of
many volcanoes is a
funnel-shaped pit called a
crater.
B. Calderas A caldera is a
large, semicircular
depression that forms
when the chamber that
supplies magma to a
volcano partially empties
and the chamber’s roof
collapses.
III. Other Types of Volcanic
Landforms
C. Lava Plateaus A landform that results
from repeated eruptions of lava spread
over a large area is called a lava plateau.
Caldera
Lava Plateau