EES Exam Review Part 4 Geohazards

Earthquakes are usually caused by the sudden movement of rocks

• at an epicenter

• at a hot spot

• along a fault scarp

• along a fault

Seismographs record

• love waves

• surface waves

• P wave

• Body waves

Which type of wave arrives at the recording station first?

• P waves

• S waves

• Rayleigh waves

• Love waves

The origin of an earthquake is

• at the epicenter

• at the focus

• where the first vibrations are felt

• only at transform faults

As the distance from the epicenter to a recording station increases, the time difference between the arrival of P and S waves __________.

• also increases.

• decreases

• fluctuates

• stays the same

The greater the distance between P and S waves

• the closer the earthquake epicenter is

• the further away the earthquake epicenter is

• the more difficult it is to tell how far the earthquake epicenter is

Use the graph to determine how far away the epicenter is if the P and S wave arrival Δt =70 seconds?

(a)  

In which seismogram is the time probe placed at the beginning of the P-waves?

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• A

• B

• C

• D

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  Suppose that an earthquake has just occurred, as pictured below. The first P-wave is shown as the larger circle (the purple one) and the first S-wave is shown as the smaller circle (the green one). What would the seismogram in Recording Station A display at the moment the image below was taken?

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1. Which of the following has the two vertical probes in the proper positions to find the correct value for Δt?

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