Geology 101 EXAM 3 (modules 7, 8, & 9)

What is the minimum number of seismic stations that is normally required to locate the epicenter of an earthquake?

3

The scientist who first hypothesized sea floor spreading was ________.

Harry Hess

Which of the following correctly lists the order in which seismic waves arrive at a seismograph station?

P waves, S waves, L waves

These types of seismic waves propagate by compression (push-pull).

P-waves

Most young mountain belts are located near plate boundaries.

True

When viewed horizontally, the limbs of a syncline resemble a "V" pointing up toward the Earth's surface.

True

For those standing on the shoreline, the first sign of a tsunami is usually:

a sudden drop in the water level that exposes the sea floor

Reverse faults result from:

compressional stress

Thrust faults result from:

compressional stress

Alfred Wegner's hypothesis for movement of the continents was termed:

continental drift

This is the angle that a rock surface makes with respect to Earth's horizontal surface.

dip

What two measurements describe the orientation of a fault plane at a given location?

dip and strike

A fracture in the Earth along which measureable movement takes place is called a:

fault

Earthquakes originate within the Earth at a point referred to as the:

focus

Plate tectonics is responsible for all the following except _________________.

hurricanes

A present day example of an oceanic-continental convergent boundary is:

Andes Mountains

This type of fault is commonly associated with convergent plate boundaries.

reverse

Left-lateral strike-slip faults result from:

shear stress

P waves moving through solid earth _______ when they encounter liquid.

slow down

The imaginary line formed by the intersection of an inclined sedimentary layer and a horizontal plane is called the ______.

strike

Which of the following conditions of natural deformation would be the most difficult to simulate in a laboratory experiment?

the duration of the deformation event

Which of the following measurements collected from seismograph stations gives scientists information regarding the type of faulting that occurred during an earthquake?

the first motion of the P waves

Transform faults are necessary to accommodate the motion of Earth's plates because:

the plates are all different shapes and move in different directions

As the distance from a seismograph to an earthquake increases, __________.

the time between the arrival of the P and S waves increases

The San Andreas Fault is much more complicated in the Los Angeles area than in Northern California because:

there is a kink, or bend in the plate boundary near LA

Earthquakes occur only on reverse and normal faults

False

New ocean floor is formed all along the western coast of South America.

False

P and S wave velocities slow down as they propogate deeper in Earth's mantle.

False

S wave velocities speed up in Earth's outer core.

False

The needle on a compass points south when the Earth's magnetic field has normal polarity.

False

When viewed horizontally, the limbs of an anticline resemble a "V" pointing up toward the Earth's surface.

False

Which of the following statements is true regarding P waves?

are faster than shear waves and surface waves

The surface that divides a fold into two halves is called the __________.

axial plane

The existence of mid-ocean ridges was first discovered by:

Harry Hess during World War II

Which of the following states has the highest earthquake risk?

Hawaii