Section 12.6 – Location and Size of Earthquakes

41.On this time-travel curve, if a large earthquake is 400 km away from the station, what can you say about the arrivals of the P- and S-waves?             

a)the P-waves will arrive 40 seconds before the S-waves

b)the P-waves will arrive 400 seconds before the S-waves

c)no S-waves will arrive at this distance from the earthquake

d)none of these

42.Using this nomogram, what is the magnitude of an earthquake that is 500 km from a seismic station and has an amplitude of 0.2 mm?             

a)2.0

b)4.0

c)6.0

d)7.0

e)10.2

43.The diagram on the right shows the record of one earthquake on seismograms at three different stations in a seismic network. These three seismograms show:a)              ISCO station is closest to the earthquake

b)WUAZ station was right at the earthquake

c)DUG station is farthest from the earthquake

d)WUAZ is the closest station, followed by DUG, and then ISCO

e)none of these

44.The diagram on the right shows data from a single earthquake plotted on a diagram that shows the mathematical relationship between distance, magnitude, and S-wave amplitude. What do these data show?             

a)the distance between stations WUAZ and DUG is 680 km

b)station ISCO is 22 km from the earthquake epicenter

c)the local magnitude of the earthquake recorded by these three stations is 4.1 MI

d)station DUG was closest to the earthquake

45.The Modified Mercalli Intensity rating map on the right shows intensity values that range from more than X to less than III. What does this map show?             

a)this earthquake had a Richter magnitude of 10 or 11 near the source

b)this earthquake had a Richter magnitude of 3 or 6 along the East Coast

c)the earthquake was not felt in southern Florida

d)shaking was felt only very near to the earthquake

e)building damage occurred in all of the zones that are shaded on this map

46.How do we determine the location of a recent earthquake?

a)measure the amplitude of surface waves in a single station

b)point video cameras at the landscape to record which way the surface moves

c)use seismic records from three or more stations

d)read old newspaper accounts of how the land moved

e)none of these

47.Based on the three seismograms, which seismic station was closest to the epicenter of the earthquake?             

a)ISCO

b)DUG

c)WUAZ

d)All stations were the same distance from the earthquake

48.If three seismic stations have the following P-S intervals: DUG = 57 sec, WUAZ = 73 sec, ISCO = 14 sec, what is the order from closest station to the earthquake to the one farthest away?

a)ISCO-DUG-WUAZ

b)DUG-ISCO-WUAZ

c)WUAZ-DUG ISCO

d)ISCO-WUAZ-DUG

49.Which are true of “Richter” or “Local” magnitude calculations?

a)Use maximum S-wave amplitude on a seismogram

b)Use a nomograph to relate distance, magnitude, and amplitude

c)Most commonly used

d)All of these are true

Section 12. 7 – Earthquake Damage

50.Shaking during an earthquake can:

a)liquefy unconsolidated sediments, causing destruction of buildings on top of them

b)generate a tsunami

c)trigger landslides

d)cause rigid buildings to collapse

e)all of these