Geo: Week six study question

What do vertical and horizontal surface waves have in common?

Both waves travel along Earth's surface and decrease in amplitude with depth below the surface

Alluvial fans are composed of material built up from sediment from the door of the mountains to the valley floor. They are evidence that ________.

Death Valley is tectonically active region

Which of the following might be seen where striking-slip movement has occurred?

offset fences

what is a scarp?

the trace of a fracture called a normal fault, where a portion of crust slides down the fault surface

Consider these real-word items. Which of them illustrates elastic rebound or behaves like rocks prior to and during an earthquake?

1. a rubber eraser 2. silly putty 3. bungee cord 4. play-doh Correct answer 2&4

On average, how many damaging earthquakes occur each year?

1000

What is the underlying principle of seismograph construction?

A heavy weight suspended within a moving box needs to overcome inertia, resulting in a slight delay in the motion of the weight after the box moves.

what causes an earthquake such as the one that occurred in San Francisco in 1906?

As plate move, stress builds up at the boundary. When the boundary eventually snaps, energy is released as an earthquake.

If the stress applied to the rock is greater than rock strength, what happens?

Blocks of rock will slide relative to one another along a fault, causing an earthquake.

Where do body waves and surface waves travel?

Body waves travel within Earth, and surface waves travel along Earth's surface.

Which of the following scenarios best describes the deformation that will occur in different parts of the crust?

Brittle deformation is dominant in the shallow crust: ductile deformation is dominant in the deep crust.

How are elastic rebound and elastic deformation different?

Elastic deformation causes objects to bend, whereas rebound causes objects to return to their original shape

Which of the following events allows rocks on either side of a fault to rebound elastically, causing an earthquake?

Friction along the fault plane is overcome

Name two types of body waves

P waves and S waves

What type of plate interaction produces the San Andreas Fault?

Plates sliding past one another

How does rock within Earth change as S waves pass?

Rocks within Earth are displaced up and down as S waves pass.

How do rocks within Earth change as P waves pass?

Rocks within Earth both expand and contract as P waves pass.

How are S waves and vertical surface waves different?

S waves are body waves, whereas vertical surface waves are surface waves. The amplitude of S waves does not decrease with depth, but the amplitude of vertical surface waves does not decrease with depth.

What will happen to a straight fence that undergoes elastic strain during an earthquake

The fence will bend in the direction of stress

The split cinder cone along the Southern Death Valley Fault is evidence that _______.

The pacific and North American plates are moving alongside each other along strike-slip faults

The bend in the stone walls in the town of Hollister, California are a result of __________.

a fault creep along the Calaveras Fault

When will the first earthquake waves arrive at a seismograph station?

a short time after the earthquake occurs

What is a seismograph?

an instrument used to record earthquake waves

What kind of force would create the fault in Figure 1

compression

Which type of force is responsible for reverse fault formation?

compressional force

The hanging wall moves______ relative to the footwall in a _____ fault.

down;normal

The Basin and Range consists of north-south trending mountain ranges separated by basins. What causes this distinct topography?

extension due to normal faulting causes valley floor to sink

When a fault is expressed at the surface, it is called a _______.

fault scarp

Most earthquakes are the result of movement along which of the following features?

faults

The point within Earth from which earthquake wave energy radiates is known by which of the following terms?

focus

Which of the following is an example of how rocks will respond to compressional stress?

folding and reverse faulting

What is a fault?

fractures along which rocks move

The name of the site where slippage begins and earthquake waves radiate outward is called the __________.

hypocenter

Earth's outer layer is composed of seven dominant plates. What is the name of this rigid outer layer?

lithosphere

Which fault will see the hanging wall move down relative to the footwall?

normal fault

______ faults combine elements of strike-slip and dip-slip motions

oblique-slip

which kind of fault is visible in Figure 1

reverse fault

The offset of Wallace Creek is caused by __________.

right-lateral movement along the San Andreas strike-slip fault

How long does it typically take for the first earthquake waves to arrive at a seismograph that is some distance away from the epicenter after the earthquake occurs

several minutes

Which type of force is responsible for normal strike-slip formation

shear force

Which of the following describes the type of deformation experienced by rocks before an earthquake?

slow deformation

Elastic deformation before an earthquake is like _______, whereas rupture is like__________.

stretching a rubber band; breaking a rubber band

Which type of fault has NO vertical motion of rocks associated with it?

strike-slip fault

what are the two primary types of waves generated by earthquakes?

surface waves and body waves

Which tectonic stress will result in a lengthening of the crust?

tension

Which type of force is responsible for normal fault formation?

tensional force

What are rocks below and above a fault called?

the footwall below and the hanging wall above