Which is the best definition of a volcano?
a) a feature that forms when magma reaches the Earth's surface
b) a feature that forms when collisions between plates pushes the crust upward
c) a feature that forms when plates boundaries slide horizontally past ech other
d) a feature that forms when magma squeezes into cracks below Earth's surface
a) a feature that forms when magma reaches the Earth's surface
100
How does volcanic ash compare to ashes from wood?
A) They are exactly alike.
B) They are similar, except volcanic ash has
sharp particles.
C) There is nothing similar about them.
D) They are similar, except wood ash has no
grains of material.
B) They are similar, except volcanic ash has
sharp particles.
100
Fissure eruptions occur at _______.
A) island arcs
B) convergent plate boundaries
C) divergent plate boundaries
D) ocean trenches
c) divergent plate boundaries
100
Gas emissions from volcanoes can be hazardous because ________ can be formed.
A) ash clouds
B) acidic precipitation
C) a lahar
D) small earthquakes
B) acidic precipitation
100
What do colliding plates have to do with volcanoes?
A) The plate that gets pushed underground
melts to become magma.
B) Colliding plates have nothing to do with
volcanoes.
C) The plate that gets pushed up creates a
volcano.
D) The plates that separate create a
volcano.
C) The plate that gets pushed up creates a volcano.
Feedback: Colliding plates cause plates to get pushed underground. This melts the rock into magma, which is expelled from volcanoes as lava.
200
Because magma is less dense than the rocks surrounding it in the mantle, magma ______________.
A) causes quiet eruptions
B) is forced downward
C) causes explosive eruptions
D) is forced upward
D) is forced upward
200
Which of these is not a type of volcano?
A) composite
B) cinder cone
C) shield
D) sill
D) sill
200
A _______ forms when an oceanic plate slides under a continental plate.
A) ocean trench
B) island arc
C) mid-ocean ridge
D) volcanic arc
D) Volcanic arc
200
Volcanic ash from an eruption can bury plants and animals, and _______.
A) start fires
B) form acidic precipitation
C) contaminate water supplies
D) release smoke
C) contaminate water supplies
200
_________ is made up of alternating tephra and lava layers.
A) No volcano
B) Cinder cone volcanoes
C) Shield volcanoes
D) Composite volcanoes
D) Composite volcanoes
300
Magma is formed at a ___________when an oceanic plate slides beneath another plate and partially melts.
A) hot spot
B) divergent plate boundary
C) convergent plate boundary
D) batholith
c) convergent plate boundary
300
Dissolved gases in magma, such as water vapor, tend to cause _______.
A) explosive eruptions
B) quiet eruptions
C) fissure eruptions
D) shield volcanoes
a) explosive eruptions
300
The Hawaiian Islands were formed _______.
A) at a convergent plate boundary
B) at a divergent plate boundary
C) over a hot spot
D) over a mid-ocean ridge
c) over a hot spot
300
What kind of lava is most explosive?
A) lava that is low in silica
B) lava that is high in silica
C) lava that is high in iron
D) lava that is high in magnesium
B) lava that is high in silica
300
What is the connection between volcanoes and plate tectonic movement?
A) Volcanoes cause plate tectonic
movement.
B) No connection exists between volcanoes
and plate tectonic movement.
C) Plate movement causes rocks to melt into
magma.
D) Plate movement causes rock to harden
and cool underground.
C) Plate movement causes rocks to melt into
magma.
400
Explosive eruptions tend to occur if the magma _______.
A) is basaltic
B) has a low viscosity
C) contains a high percentage of silica
D) contains a low percentage of silica
c) contains a high percentage of silica
400
A _______ is the depression formed when the top of a volcano collapses.
A) batholith
B) dike
C) sill
D) caldera
d) caldera
400
The Hawaiian Islands are examples of _______.
A) fissure eruptions
B) composite volcanoes
C) shield volcanoes
D) batholiths
c) Shield volcanoes
400
Which of these is not an environmental hazard caused by a volcano? 2.d
A) lava
B) volcanic ash
C) acid rain
D) radiation
d) radiation
400
A collapsed volcano fills with water creating a lake. This is an example of a ________. 1.d
A) lava tube
B) caldera
C) lava dome
D) sill
B) caldera
500
Why do so many volcanoes form on divergent and convergent plate boundaries?
A) These plates get pushed up and create
volcanoes.
B) Converging and diverging plates have
nothing to do with volcanoes.
C) because melting plates cause magma to
form beneath the surface.
D) These plate separate to create volcanoes.
C) because melting plates cause magma to form beneath the surface.
500
A fast-moving mass of hot gases and solids produced by an explosive eruption is a _______.
A) lava tube
B) lava flow
C) lahar
D) pyroclastic flow
d) pyroclastic flow
500
Volcanoes in California are part of a volcanic arc formed where _______.
A) the Juan de Fuca plate subducts beneath the North American plate
B) the Juan de Fuca plate slides horizontally past the North American plate
C) the Pacific plate slides horizontally past the North American plate
D) the Pacific plate subducts beneath the North American plate
A) the Juan de Fuca plate subducts beneath the North American plate
500
Which of these describes granitic magma? 1.d
A) high silica, slow moving
B) high silica, fast moving
C) low silica, slow moving
D) low silica, fast moving
A) high silica, slow moving
500
What is tephra?
A) lava that is slowly released from fissures
B) lava that cools beneath the surface
before an eruption
C) very fluid lava
D) lava that has cooled in midair after an
eruption
D) lava that has cooled in midair after an
eruption