ERSC181 Verified Multiple Choice and Conceptual
Actual Exam Questions With Reviewed 100%
Correct Detailed Answers
Guaranteed Pass!!Current Update
1. P wave - ANSWER Seismic wave that compresses and stretches the
material it moves through
- fastest seismic wave
- slinky
- through rock and liquid
2. S wave - ANSWER Type of seismic body wave that can only move
through solids
- secondary wave
- slower than P wave
- only get transmitted through materials that are resistant to a change
in shape (only solid rock)
3. Surface wave - ANSWER Seismic waves that travel along the Earth's
surface
- slower than P and S waves
- cause rolling motion like ocean waves
- can cause side-to-side shaking
- generally cause of earthquake damage and have highest amplitude
on seismogram
,4. triangulation (for epicenter) - ANSWER If three different seismometers
record an earthquake, the location of the earthquake can be calculated. The
focus is the point in the Earth that broke based on elastic rebound theory
but the point on the map directly above the focus is the epicenter. Each
station will calculate the distance to the epicenter based on the arrival
times of P and S-waves. One seismogram can calculate the distance to an
earthquake, but not the direction that the waves are traveling. With three
sets of data, three circles of distance to the epicenter can be drawn and
where the three circles intersect is the location of the epicenter. This
process is called triangulation.
5. Richter Scale - ANSWER - based on the recorded heights of seismic
waves on a seismograph
- needs to be some accounting of how far away the epicenter is; it isn't
a strict measurement of the wave height on the seismograph
- Richter scale is logarithmic which means that the increase in
earthquake size between units is actually a 10-fold increase in energy
- magnitude 5 earthquake is 10 times larger wave height on a
seismogram than a magnitude 4 earthquake
- magnitude 6 earthquake is 100 times larger wave height on a
seismogram than a magnitude 4
- when considering the energy released in an earthquake and the
resulting damage, each unit on the Richter scale has 32 times more
energy
6. Difference between Richter scale and Moment Magnitude scale - ANSWER
primary difference between these two scales is that the Richter scale
assumes the earthquake focus is a small point from which the seismic
waves propagate. The Moment Magnitude scale considers that energy in an
earthquake may be released over a large area
, 7. Modified Mercalli Intensity Scale - ANSWER The Modified Mercalli
Intensity Scale is a ranking system of 12 levels describing how different size
quakes may feel. This scale is useful for the nontechnical person. The details
for the ranking include "some dishes, windows broken" or "fall of chimneys,
walls etc." There is no need for a seismometer to quantify the intensity of
an earthquake.
8. Three things can happen to seismic wave traveling through the Earth -
ANSWER 1. The seismic wave can refract which means the wave bends.
The bending of seismic waves or light rays happens when the wave passes
between two materials of different densities. The density impacts the speed
of the seismic wave.
2. The seismic wave can also be reflected which means it bounces back at the
boundary between two different materials.
3. The energy can also be absorbed which means it is blocked and essentially
disappears.
9. waves and seismic discontinuity - ANSWER The different layers in the
Earth have different chemistry, density, are liquid or solid and cause seismic
waves to be bent, reflected, or absorbed.
- These different layers are seismic discontinuities.
- Seismic discontinuities help geologists map the boundaries of the
core, mantle, and crust.
- P-waves are refracted at various seismic discontinuities at the
mantle/outer core boundary as well as at the inner/outer core
boundary.
- S-waves cannot pass through liquids so their absorption at the outer
core/mantle boundary indicates the outer core is liquid.
Actual Exam Questions With Reviewed 100%
Correct Detailed Answers
Guaranteed Pass!!Current Update
1. P wave - ANSWER Seismic wave that compresses and stretches the
material it moves through
- fastest seismic wave
- slinky
- through rock and liquid
2. S wave - ANSWER Type of seismic body wave that can only move
through solids
- secondary wave
- slower than P wave
- only get transmitted through materials that are resistant to a change
in shape (only solid rock)
3. Surface wave - ANSWER Seismic waves that travel along the Earth's
surface
- slower than P and S waves
- cause rolling motion like ocean waves
- can cause side-to-side shaking
- generally cause of earthquake damage and have highest amplitude
on seismogram
,4. triangulation (for epicenter) - ANSWER If three different seismometers
record an earthquake, the location of the earthquake can be calculated. The
focus is the point in the Earth that broke based on elastic rebound theory
but the point on the map directly above the focus is the epicenter. Each
station will calculate the distance to the epicenter based on the arrival
times of P and S-waves. One seismogram can calculate the distance to an
earthquake, but not the direction that the waves are traveling. With three
sets of data, three circles of distance to the epicenter can be drawn and
where the three circles intersect is the location of the epicenter. This
process is called triangulation.
5. Richter Scale - ANSWER - based on the recorded heights of seismic
waves on a seismograph
- needs to be some accounting of how far away the epicenter is; it isn't
a strict measurement of the wave height on the seismograph
- Richter scale is logarithmic which means that the increase in
earthquake size between units is actually a 10-fold increase in energy
- magnitude 5 earthquake is 10 times larger wave height on a
seismogram than a magnitude 4 earthquake
- magnitude 6 earthquake is 100 times larger wave height on a
seismogram than a magnitude 4
- when considering the energy released in an earthquake and the
resulting damage, each unit on the Richter scale has 32 times more
energy
6. Difference between Richter scale and Moment Magnitude scale - ANSWER
primary difference between these two scales is that the Richter scale
assumes the earthquake focus is a small point from which the seismic
waves propagate. The Moment Magnitude scale considers that energy in an
earthquake may be released over a large area
, 7. Modified Mercalli Intensity Scale - ANSWER The Modified Mercalli
Intensity Scale is a ranking system of 12 levels describing how different size
quakes may feel. This scale is useful for the nontechnical person. The details
for the ranking include "some dishes, windows broken" or "fall of chimneys,
walls etc." There is no need for a seismometer to quantify the intensity of
an earthquake.
8. Three things can happen to seismic wave traveling through the Earth -
ANSWER 1. The seismic wave can refract which means the wave bends.
The bending of seismic waves or light rays happens when the wave passes
between two materials of different densities. The density impacts the speed
of the seismic wave.
2. The seismic wave can also be reflected which means it bounces back at the
boundary between two different materials.
3. The energy can also be absorbed which means it is blocked and essentially
disappears.
9. waves and seismic discontinuity - ANSWER The different layers in the
Earth have different chemistry, density, are liquid or solid and cause seismic
waves to be bent, reflected, or absorbed.
- These different layers are seismic discontinuities.
- Seismic discontinuities help geologists map the boundaries of the
core, mantle, and crust.
- P-waves are refracted at various seismic discontinuities at the
mantle/outer core boundary as well as at the inner/outer core
boundary.
- S-waves cannot pass through liquids so their absorption at the outer
core/mantle boundary indicates the outer core is liquid.
