| What are the 2 scales to measure the intensity of an earthquake? | Mercalli Scale
European Macroseismic Scale |
| What are the 2 scales to measure the intensity of an earthquake? | Mercalli Scale
European Macroseismic Scale |
| What is the Hypocenter of an earthquake? | The area of origin of the earthquake waves. (Focal point) |
| What is the Epicenter of an earthquake? | Ther vertical projection of the hypocenter onto the surface. |
| What is the Hearth depth of an earthquake? | The distance from the hypocenter to the surface. |
| What is the Hearth area of an earthquake? | The area of the fault that causes the earthquake. |
| True or false: The hypocenter is an initiation point that lies on the fault and the focal plane. | True |
| True or False: During the earthquake, the focal area propogates toward the hypocenter in all directions. | False. The focal area propogates away from the hypocenter in all directions. |
| True or False: The focal area propogates slower than seismic waves. | False. The focal area propogates at the same speed. |
| What is the amplitude of a wave? | The height of the wave from the x axis. |
| What is a wavelength? | The distance between the highest point of two waves. |
| What is frequency? | The number of wavelengths that are measured over a period of time. |
| What is Reflection of a wave? | When waves bounce off a surface. |
| What is refraction of a wave? | When a wave passes into another medium and changes direction *slightly* |
| What types of space waves are there? How do they appear on a seisogram? | Primary waves (P-waves) arrive first, fast. P-waves travel through solids and liquids.
Secondary waves (S-waves) arrive later and slower. S-waves only travel through solid bodies. |
| What types of surface waves are there? How do they appear on a seismogram? | -Surface waves spread throught he surface of the earth, are very slow, have greater amplitude than space waves.
-Lowe-Waves: cause horizontal displacement.
-Rayleigh-Waves: cause longitudinal and transverse movements. |
| True or False: Only surface waves cause damage to buildings. | True |
| True or false: Lowe-waves cause side to side motion that cause strcutural damage. | True |
| True or False: Rayleigh waves cause side to side and up and down movement that liquifies soil. | True |
| True or False: Velocity is smaller in saturated material | False. Waves travel faster in saturated material. |
| True or False: Velocity travels slower in non-solid materials/sediments. | True |
| True or False: Velocity travels slower through unbroken broken rocks. | False. Waves travel faster through unbroken rocks. |
| True or False: If energy waves travel through the ground slower, they cause less damage. | False. They cause more damage because when the velocity slows the amplitude increases. (Less velocity -> More shaking) |
| What are the two scales to measure the magnitude of an earthquake? | Richter Scale
Moment Magnitude Scale |
| What are the 2 scales to measure the intensity of an earthquake? | Mercalli Scale
European Macroseismic Scale |
| True or False: In the Richter scale, each increase in magntiude is 32 times stronger. | True |
| Explain the formula for the Moment magnitude scale. | The seismic moment = Shear modulus x Average displacement x Hearth area |
| What is Peak Ground Acceleration? | Maximum ground acceleration recorded at a location of an earthquake, measured in G. |
| What is Spectral Acceleration? | Maximum acceration of a structure duing an earthquake, measured in G. |
| True or False: When a structure has a short occilation period, it receives more damage. | True. |
| True or False: Tall buildings have longer oscillation periods than short buildings. | True |
| M>6
M<4
M<5
Which of these magnitudes correspond with Zone A and B in Vietnam. | M>6 |
| M>6
M<4
M<5
Which of these magnitudes correspond with Zone C and D in Vietnam. | M<4 |
| M>6
M<4
M<5
Which of these magnitudes correspond with Zone E and D in Vietnam. | M<5 |
| Is the earthquake hazard in Vietnam classified as Low, Medium or High. | Medium. |
| Which fault zone are the strongest earthquakes in Vietnam associated with? | Red River Fault Zone |
| Name the effects of earthquakes (7) | Tsunami
Landslide
Coastal change
Liquefection
Surface rupture
Forestorm
Shaking |
| What kinds of earthquakes are there? | Tectonic earthquakes 90%
Volcanic earthquakes 7%
Collapse and other earthquakes 3% (when underground cavities collapse or triggered earthquakes from human activity) |
