earth science unit 3/4
Physical weathering rates are highest in areas with
constant freezing and thawing
Volcanoes that form far from plate boundaries form as the result of __________.
hot spots
What is a farming method that can reduce the effect of erosion?
planting wind barriers
What are most earthquakes associated with?
plate boundaries
Where do most volcanoes form?
plate boundaries
When a divergent plate boundary forms on continents, a ______ forms.
rift valley
What causes the seafloor to spread?
rising magma
When magma reaches Earth's surface it is called __________.
lava
Which wave arrives at a seismic facility first?
P wave
What is the rating from the Richter scale based on?
amplitude-size of the largest waves
How is a volcanic crater connected to a magma chamber?
by a vent
Which of the following could increase the rate of chemical weathering of a rock? a. moving it to a location with few plants and animals b. moving it to a drier climate c. increasing its total surface area d. moving it to a colder climate
c
What is the name of a large volcanic crater over 1 km in diameter?
calderas
The subduction of an oceanic plate beneath a continental plate produces a(n) ________.
chain of volcanos
The process by which rocks and minerals undergo changes in their composition as the result of chemical reactions is known as
chemical weathering.
What is formed by the deposition of large amounts of sediment into a body of water by a river?
deltas
In a process known as __________ , eroded materials are dropped in another location.
deposition
What are shallow, intermediate, and deep earthquake classifications based on?
depth of focus
Places where two tectonic plates are moving away from each other are called
divergent boundary.
______________ is the removal and transportation of weathered material from one location to another.
erosion
The process by which outer layers of a rock are stripped away is called
exfoliation
What evidence did Wegener use to estimate the time of Pangaea's break up?
fossils
The repeated thawing and freezing of water in the cracks of rocks is known as
frost wedging
The breakdown of rocks into smaller pieces is known as
mechanical weathering
Where are the youngest rocks on the seafloor located?
mid-ocean ridge
What is the polarity of a magnetic field that has the same polarity as the present magnetic field?
normal polarity
What type of instrument can measure the vibrations of an earthquake?
seismograph
A wide, dome-shaped volcano built from thin, freely flowing lava is called a(n) _______ volcano.
shield
How are the convection currents set in motion?
slab push and ridge pull
What is the process called when one plate is forced beneath another at a convergent plate boundary?
subduction
The rate of chemical weathering is less in Antarctica than in the rain forests of Brazil because of _______.
temps are lower; drier
Which type of stress pulls a material apart?
tension
Rock fragments thrown into the air during a volcanic eruption are called __________.
tephra
A place where two plates slide laterally past each other is called a __________.
transform boundary
A large ocean wave that is generated by vertical motions of the seafloor during an earthquake is called a(n) ____________.
tsunami
What is a rating for an earthquake from the modified Mercalli scaled based on?
used to measure intensity; damage caused
In what type of climate does chemical weathering readily occur?
warm lush areas
The process by which rocks on or near Earth's surface break down and change is
weathering
When does magma form?
when temperatures are hot enough to melt rock (1000 degrees)
What type of volcano forms alternating layers of tephra and nonexplosive lava?
composite
What is the name of Alfred Wegener's hypothesis about moving landmasses?
continental drift
What is thought to be the driving mechanism of plate movement?
convection currents in the mantle
The ____________ the total surface area, the _________ chemical weathering that can occur.
greater; more
_______________ is the erosion by running water of a small channel on the side of a slope.
Rill erosion
What is the study of Earth's magnetic record?
Paleomagnetism
Which of the following happens when a river enters a large body of water? a. The river water slows down and deposits large amounts of sediments. b. The river water increases its speed and carries out gully erosion. c. The river water flows over the delta, causing exfoliation. d. The river water erodes the shoreline and deposits barrier islands.
a
Which of the following is most likely to break apart a rock? a. Oxidation b. Frost wedging c. Dissolving products d. Feldspar weathering
b
Which of the following characteristics of water can be responsible for mechanical weathering? a. Water flows downstream under gravity. b. Water expands when it freezes. c. Water combines with atmospheric gases to form acid precipitation. d. Water reacts with and can dissolve many kinds of minerals.
b.
How does temperature affect chemical weathering?
it affects the rate of weathering
Why does magma move up to and through Earth's crust?
it is less dense then the surrounding rock