Download What is the crack in the ocean floor through which magma rises

What is the crack in the ocean floor through which magma rises?
a.
a ridge
c.
a rift
b.
a rip
d.
a rent
Magnetic patterns on the ocean floor were puzzling because they
a.
showed alternating bands of normal and reversed polarity.
b.
indicated that all ocean rocks had reversed polarity.
c.
were not symmetrical.
d.
contradicted the idea of sea-floor spreading.
Wegener’s hypothesis of continental drift was finally confirmed by
a.
fossils from the same reptile found on two continents.
b.
evidence supporting the idea of sea-floor spreading.
c.
continental coastlines that fit together.
d.
the formation of mountain ranges such as the Andes.
The Pacific Ring of Fire is
a.
a mid-ocean ridge.
b.
a chain of volcanic islands.
c.
d.
a zone of active volcanoes.
a rift valley.
The Himalaya Mountains were formed in a collision at a
a.
divergent boundary.
c.
transform boundary.
b.
convergent boundary. d.
fracture zone.
An example of a transform boundary is the
a.
San Andreas Fault in California.
b.
Nazca plate on the west coast of South America.
c.
Eurasian plate at the Mid-Atlantic Ridge.
d.
island arc of Japan.
The theory that explains why and how continents move is called
a.
continental drift.
c.
plate tectonics.
b.
paleomagnetism.
d.
sea-floor spreading.
Frequent earthquakes in an area may indicate
a.
tectonic plate boundaries.
c.
b.
sea-floor spreading.
d.
mantle convection.
reversed polarity.
Tectonic plates are blocks of
a.
magma.
b.
magnetic rock.
c.
d.
asthenosphere.
lithosphere.
At the center of a mid-ocean ridge is a(n)
a.
subduction zone.
c.
rift valley.
b.
fracture zone.
d.
deep-ocean trench.
What occurs at a transform boundary?
a.
Oceanic lithosphere collides with continental lithosphere.
b.
Magma rises to the surface and forms a mid-ocean ridge.
c.
Two plates slide past each other horizontally.
d.
Two plates collide and crumple.
Where do deep-ocean trenches form?
a.
in island arcs
b.
at convergent boundaries
c.
d.
in fracture zones
at transform boundaries
Isostatic adjustments occur in
a.
the ionosphere.
b.
the atmosphere.
c.
d.
the lithosphere.
volcanoes.
What is isostasy?
a.
gravitational and buoyant incongruity between the asthenosphere and the lithosphere
b.
gravitational and buoyant equilibrium between the asthenosphere and the lithosphere
c.
buoyancy in the asthenosphere overcomes gravity in the lithosphere
d.
gravity and buoyancy cause the atmosphere to rise
Folded mountains form
a.
when a state of isostasy occurs.
b.
when continents collide.
c.
d.
when continents diverge.
after huge earthquakes.
When the oceanic and continental lithospheres collide,
a.
the oceanic plate subducts.
c.
their momentum stops each other.
b.
the continental plate subducts. d.
they reach isostasy.
What happens when two oceanic plates collide?
a.
The denser plate fractures.
c.
The less dense plate subducts.
b.
The less dense plate fractures. d.
The denser plate subducts.
What type of mountain is formed when higher blocks fault?
a.
a folded mountain
c.
a fault-block mountain
b.
a salt-block mountain d.
a flawed-block mountain
What happens when two continental plates collide?
a.
Large mountains can form.
c.
b.
Dome mountains are likely to form.
d.
The plates subduct beneath each other.
The impact can cause huge earthquakes.
What is subduction?
a.
one plate collides with another c.
b.
one plate destroys another
d.
one plate goes beneath another
one plate divides another
Which of these are types of mountains?
a.
rolling, glacial, subterranean, cascades c.
b.
rocky, green, smoky, white
d.
fault-block, dome, volcanic, folded
salt-block, dome, magnum, frozen
A dome mountain is a mountain formed
a.
by the collision of continental plates.
b.
by the eruption of magma from below Earth’s surface.
c.
when faults break off dome-shaped rock blocks.
d.
by pressure from magma below Earth’s surface that does not erupt.
A volcanic mountain is formed by
a.
the uplift of rock during continental plate collisions.
b.
rock layers that are bent and squeezed through magma pressure.
c.
the pressure of magma that does not erupt on the Earth’s surface.
d.
magma eruptions on Earth’s surface.
What are the fastest body waves?
a.
P waves
c.
b.
T waves
d.
S waves
Q waves
Earthquakes generally occur at plate boundaries, where
a.
stress on rocks is greatest.
c.
stress on rocks is low.
b.
the most rock is found.
d.
magnetic pull is greatest.
To find the distance to an earthquake’s epicenter, scientists
a.
chart the lag time between preshocks and aftershocks.
b.
use radio wave detection devices.
c.
analyze the arrival times of the P waves and S waves.
d.
analyze the arrival times of the Love waves and Rayleigh waves.
To locate the epicenter of earthquakes, scientists use computers to
a.
analyze hypotheses and theories.
b.
perform triangulations based on data from seismograph stations.
c.
detect vibrations.
d.
determine magnitude and intensity.
If you are in a car during an earthquake, you should
a.
drive toward a bridge.
c.
get out and run.
b.
stop the car in a safe place.
d.
park near a tall building.
What happens to tsunamis as they move toward shore?
a.
The decrease in height.
c.
They turn into riptides.
b.
They die out.
d.
They increase in height.
At what location does the first motion of an earthquake occur?
a.
the focus
c.
the mantle
b.
the seismic gap
d.
the epicenter
Why do earthquakes usually occur at plate boundaries?
a.
The rock on the edges of tectonic plates is soft and gives in easily to various pressures.
b.
Rock in environments near tectonic plate boundaries experience great stress.
c.
The boundaries between tectonic plates have been seismically active for millions of years.
d.
Rock in environments near tectonic plate boundaries experience little stress.
P waves are also known as
a.
secondary waves.
b.
compression waves.
c.
d.
Love waves.
Rayleigh waves.
What is the epicenter of an earthquake?
a.
the location along a fault where the first motion of an earthquake occurs
b.
a seismic wave that travels along the surface of Earth
c.
the point on Earth’s surface directly above the earthquake’s focus
d.
the last place that motion in an earthquake is detected
What causes tsunamis?
a.
magnetic pole shifts, seismic gaps, extreme tides during winter
b.
tornadoes, volcanic eruptions, landslides
c.
changes in Earth’s ozone layer, world climate changes, glaciers
d.
undersea earthquakes, landslides, volcanic eruptions
This area is both a major earthquake zone and volcano zone.
a.
Pacific Ring of Volcanoes
c.
Oceanic Ring of Fire
b.
Pacific Ring of Fire
d.
Pacific Island Arc
What forms on the ocean floor in a subduction zone?
a.
hot spot
c.
lithosphere
b.
mantle plume
d.
trench