Spanish Section Review

Nombre
Clase
Fecha
Hoja de destrezas
Repaso de la sección
Efectos de las erupciones volcánicas
USAR TÉRMINOS CLAVE
1. Escribe una oración distinta con cada uno de los siguientes términos: cráter, caldera
y meseta de lava.
COMPRENDER LAS IDEAS PRINCIPALES
2. Predice los efectos que la ceniza y los gases de una erupción volcánica pueden tener
sobre el clima de la Tierra.
3. Explica por qué los volcanes de cono de escorias tienen bases más estrechas y
laderas más empinadas que los volcanes de escudo.
4. Compara los tres tipos de volcanes.
5. Compara los cráteres y las calderas.
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Volcanes
Nombre
Clase
Fecha
Repaso de la sección (continuación)
RAZONAMIENTO CRÍTICO
6. Inferir ¿Por qué los efectos de la erupción del Tambora no se sintieron en Nueva
Inglaterra sino hasta un año después?
FCAT PREPARACIÓN
______ 7. ¿Cuál de los siguientes efectos es más probable que se produzca durante una
erupción volcánica que libera una gran cantidad de ceniza y gas?
A. Aumenta la cantidad de luz solar que llega a la Tierra.
B. Disminuye la temperatura mundial promedio.
C. Baja el nivel del mar en todo el mundo.
D. Aumenta el rendimiento de las cosechas.
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Volcanes
ANSWER KEY
3. lava plateau: a wide, flat landform that
7. Aa and pillow lava have low viscosity
results from repeated nonexplosive
eruptions of lava that spread over a
large area
because they have a low silica content.
Blocky lava has high viscosity because
it has a high silica content.
8. A
SECTION: CAUSES OF VOLCANIC
ERUPTIONS
SECTION: EFFECTS OF VOLCANIC
ERUPTIONS
1. rift zone: an area of deep rock cracks
1. A crater is a bowl-shaped depression
that forms between tectonic plates
that are pulling away from each other
2. hot spot: a volcanically active area of
Earth’s surface, commonly far from a
tectonic plate boundary
Section Review
SECTION: VOLCANIC ERUPTIONS
1. Sample answer: A volcano is a land-
2.
3.
4.
5.
6.
2.
form created by repeated eruptions of
lava. A magma chamber is an underground body of magma that feeds a
volcano. A vent is an opening through
which lava or pyroclastic material
passes.
Lava is classified by its surface texture. The way that lava flows may also
be used to help classify it. Four types
of lava are aa, pahoehoe, blocky lava,
and pillow lava. Aa flows quickly and
has a jagged crust. Pahoehoe flows
slowly and has a wrinkled surface.
Pillow lava erupts underwater and
forms rounded lumps. Blocky lava is
cool, stiff lava that does not travel far
from the erupting vent.
an explosive eruption
The presence of water increases the
chance of an explosive eruption
because as the magma body moves
toward the surface, the water changes
to a gas and expands rapidly. This rapid
expansion causes an explosion. Silicarich magma tends to trap volcanic
gases and plug vents due to its high viscosity. The resulting pressure increase
can cause an explosive eruption..
A pyroclastic flow is a cloud of very
hot ash, dust, and gases that flows
from a volcano.
Magma and soda have carbon dioxide
dissolved in them. When the pressure
on the magma or the soda is reduced,
the carbon dioxide becomes a gas and
expands rapidly.
3.
4.
5.
6.
7.
that forms around the central vent of a
volcano. A caldera is a large, circular
depression that forms when the
magma chamber below a volcano partially empties and causes the ground
to sink. A lava plateau is a landform
that results when repeated eruptions
of lava spread over a large area.
The gases and volcanic ash from a
large eruption can cause the average
global temperature on Earth to drop.
Cinder cone volcanoes are made of
pyroclastic material, which is thick
and piles up like sand around the volcano. Shield volcanoes are made from
lava that is thin and that spreads out
over large areas.
Shield volcanoes are built of layers of
lava released from nonexplosive eruptions. They have gently sloping sides
and can be enormous. Cinder cone volcanoes are made of pyroclastic material produced by moderately explosive
eruptions. These volcanoes are small
and have steep sides. Composite volcanoes form from both explosive eruptions of pyroclastic materials and
quieter flows of lava. They have broad
bases and sides that get steeper toward
the top of the volcano.
When lava and pyroclastic material
pile up around a volcanic vent, a cone
with a central crater forms. If the
magma chamber below a volcano partially empties and causes the roof of
the chamber to collapse, a caldera
forms. A caldera is usually much
larger than a crater.
It took a year for the effects of the
Tambora eruption to be experienced
in New England because the ash and
gases from the eruption had to be circulated by global winds.
B
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Volcanoes

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