Test 2 Flashcards
Which of the following is most likely to be found the greatest distance from the side of the eruption
Basaltic lava
What do as and pahoehoe lavas have in common?
Both come from low-silica basaltic magmas
What region on earth has the largest concentration of composite volcanoes?
The pacific margin
Why do magma‘s rise towards earths surface?
Magma is less dense because it is hotter than solid rock of the same composition
Why do volcanoes like Mount Saint Helens irrupt explosively, whereas others like Kilauea are relatively quiescent?
The magma is associated with Mount Saint Helens or more viscous than those associated with Kilauea because they have more silica
Which of the following would be most helpful in determining where it would be safest to live near a possible active stratovolcano?
The ages, thickness, and distribution of welded tough, lahars, and Pyroclastic deposits around the volcano 
An increase in sulfur dioxide emissions is a sign that
A major eruption may occur within the next few days to years
The difference between soil and regolith is?
Soil is the layer of Material that includes a mixture of rock fragments in organic matter, well regolith is the layer of rock fragments
Soil is considered to be an interface between spears because:
It contains water, air, rock, and organic matter
The ideal place to develop a good soil is:
On gently varying topography
By definition, the blank is composed of “Partly alter the parent material”
C - horizon
Where would you expect to get the thinnest o layer in a soil profile?
In a desert
In terrain where a steep hill slopes, which crop and cultivation technique will minimize soil erosion?
Apples; land between the trees is planted in grass and not cultivated
The major types of stress are:
Sheer, tension, and compression
Which of the following make it more likely that a Rockwell bend instead of breaking?
High confining pressure, high temperature, weak chemical bonds
Reverse faults are associated with:
Compressional stresses that characterize convergent boundaries
The relationship between stress and strain is:
The strain is the result of stress
How is brittle deformation different from ductile deformation?
Brittle deformation produces joints and faults, well ductile deformation produces folds.
The Black Hills of South Dakota or a large storm that has been deeply eroded. Where would you find the youngest exposed rocks associated with the dome?
Along the outside edges of the dome
For the fault indicated in the figure below, which side is the hanging wall?
A is the hanging wall
Which type of fault is shown in the figure below?
Normal fault
For the fault shown in the figure below, how is the region changed or deformed?
It gets longer
If I drawl a line connecting to nearby points of equal elevation on an indicated there, the orientation of that line would be called the blank direction
Strike
Over the oceans, evaporation exceeds precipitation, so why doesn’t the sea level go down?
Because the runoff from continents is about the same as the lost evaporation
If the glaciers melted, sea level would rise:
Tens of meters
How Might a water gap form?
A stream may already exist when the land starts to uplift beneath it and the stream will stay on its channel and cut down as the land goes up
What are the three main zones of a river system?
Sentimental production, sediment transport, and sediment deposition
Why does the strength of a stream increase towards the center of the stream
Because that is where the frictional residence is the least
Why does discharge (volume/distance) in a stream usually increase downstream?
Because the volume of water in the stream increases with distance from the source
Which of the following is not influenced by stream velocity?
Dissolved load
Sorting happens in a stream because:
Streams deposit their largest particles first
How does a Oxbow Lake form?
An upper meander in a stream erodes enough of its bank to connect to a lower meander and cut off intervening loop which then becomes an oxbow lake
Slot canyons form in:
Bedrock of arid regions
If the best level for an existing graded stream rises, how is the stream likely to respond?
The stream will increase sedimentation starting near the new base level and moving upstream overtime
What is causing the Mississippi river delta in the wetlands to shrink?
The construction of dams in levees on the river has decreased the sedimentary supply to the Delta and wetlands
A 100 year flood
is larger than a 50 year flood
The type of deformation associated directly with the generation of seismic waves is:
Elastic
What causes earthquakes along the San Andreas fault zone in California?
It is a transform plate boundary we are one plate a sliding past another
What type of fault is the most destructive?
Reverse
What is the relationship between the length of the fault rupture, the size of the earthquake, and the duration of the earthquake,
The largest earthquakes have the largest rupture lengths in the longest duration because there is enough energy to overcome friction over a large distance
What type of wave motion is shown in the figure below
Secondary
What type of seismic waves tend to cause the greatest destruction two buildings?
Surface waves
Why are surface waves more destructive than body waves?
Because surface waves shake the ground for longer and are stronger than body waves
Blank have the highest velocity‘s
Primary waves
An earthquake magnitude of seven releases blank times as much energy as an earthquake with a magnitude of six
32
If you build a house in an earthquake prone area, which of the following would be the best choice for building materials?
Wood
In 2004 earthquake and tsunami in Sumatra was located in which of the following systems?
Alpine Himalayan belt
Why are seismic gap so useful in making long-term earthquake predictions?
Because stress builds up steadily along plate boundaries making it likely that earthquakes will occur the regularly
