Question 1

Where the frequencies of seismic waves match the natural vibration frequencies of local geology and buildings,destruction may be great.

Accepted Answer

This phenomenon is known as resonance and can amplify the effects of seismic waves, leading to greater destruction.

Question 2

The waveforms on the seismogram from the closest seismic station are dominated by low-frequency waves,while high-frequency waves dominate at the station farther away.

Accepted Answer

High-frequency waves attenuate more rapidly with distance than low-frequency waves. Therefore, the waveforms on the seismogram from the closest seismic station are more likely to be dominated by high-frequency waves, while low-frequency waves dominate at the station farther away.

Question 3

The duration of the shaking is not a significant factor in damages suffered and lives lost.

Accepted Answer

The duration of shaking can play a significant role in the damage suffered and lives lost. Longer duration of shaking can result in more extensive damage to structures and increase the risk of injury or death for those in the affected area.

Question 4

Earthquake magnitude scales such as the Richter scale assess the effects on people and buildings.

Accepted Answer

Earthquake magnitude scales, like the Richter scale, measure the energy released by an earthquake, not the effects on people and buildings. The Modified Mercalli Intensity Scale, however, assesses the effects of earthquakes on people, buildings, and the Earth's surface.

Question 5

High-frequency P- and S-waves will have their vibrations amplified by 1)rigid construction materials,such as brick or stone,and 2)short buildings.

Accepted Answer

This is true because high-frequency waves have shorter wavelengths and are therefore more effectively amplified by rigid materials and shorter buildings.

Question 6

Other measures of earthquake magnitude may include the two magnitude scales,body wave scale (m_b)and surface wave scale (M_s)

Accepted Answer

This statement is true as there are various magnitude scales used to measure earthquakes, including the body wave scale and surface wave scale.

Question 7

Earthquakes at divergent zones,such as the East African Rift system,are generated at shallow depth (<33km)and with magnitude 6.0 or less.

Accepted Answer

Earthquakes at divergent zones, such as the East African Rift system, are generally generated at shallow depths and with magnitudes of 6.0 or less. This is because in divergent zones, the plates are moving away from each other, causing tension and small earthquakes. Larger earthquakes, with magnitudes greater than 6.0, are more common in areas where plates are colliding, such as at subduction zones.

Quiz 3: Earthquake Geology, Seismology, and Engineering