How Are Faults Hypocenters And Epicenters Related

Question: How are faults, hypocenters, and epicenters related?

Answer: The hypocenter is the exact point underground along a fault where the slippage of the two blocks of rock occurs. The epicenter is the point on Earth's surface that is directly above the hypocenter.

Question: What is meant by elastic rebound?

Answer: Elastic rebound refers to how the slippage along a fault (i.e., earthquake) allows the deformed rock to regain its original shape in a new location.

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

Answer: lithosphere

Question: What type of plate interaction produces the San Andreas Fault?

Answer: plates sliding past one another

Question: How does triangulation determine the epicenter of an earthquake?

Answer: On a map, a circle is drawn around each of three recording stations, with the radius being the distance from the station to the epicenter of the earthquake. The epicenter is located where the three circles intersect.

Question: Are accurate, short-range earthquake predictions currently possible using modern seismic instruments?

Answer: No

Question: Which type of fault tends to produce the most destructive earthquakes?

Answer: megathrust fault

Question: During an earthquake, _____.

Answer: the slippage continues along the fault until it reaches a point where rocks are not sufficiently strained to continue slippage

Question: What characteristics do faults that experience fault creep exhibit?

Answer: Fault creep tends to produce slow, gradual displacements of rock blocks with little seismic shaking.

Question: What are the differences between P waves, S waves, and surface waves?

Answer: P waves are the fastest and have the lowest amplitudes; S waves are the second-fastest and have the second-lowest amplitudes; surface waves are the slowest and have the highest amplitudes.

Question: Which type(s) of seismic waves tend(s) to cause the greatest destruction to buildings?

Answer: surface waves

Question: What information is used to establish the lower numbers on the Modified Mercalli Intensity scale?

Answer: how the earthquake is felt by people in an area

Question: Why is the moment magnitude scale favored over the Richter scale for large earthquakes?

Answer: The moment magnitude scale measures the total energy released, whereas the Richter scale only measures the amplitude of the largest seismic wave.

Question: What is liquefaction?

Answer: fluid behavior of water-filled sediment during shaking

Question: Which sediment below would have the highest cohesive strength during an earthquake?

Answer: sediment with many contact points between grains and air in pore spaces

Question: How are tsunamis generated?

Answer: through displacement of the seafloor under water

Question: What is a tsunami?

Answer: a series of water waves that travel away from a fault in all directions at high speed

Question: Why does the wave height of a tsunami increase as the tsunami enters shallow water?

Answer: In shallow water, the energy of the tsunami must be contained within a smaller water column.

Question: What type of plate boundary are most tsunamis associated with?

Answer: convergent plate boundaries