Week 3 Multiple Choice
Which statement is TRUE? a. Raleigh and Love waves are surface seismic waves. b. S-waves are compressional body waves P-waves are shear body waves. c. Surface waves are the first to show up on a seismogram recording of a quake. d. Shallow-focus quakes do less damage than deep-focus quakes.
a. Raleigh and Love waves are surface seismic waves.
At depths below 100 km, subduction zone earthquakes occur almost exclusively in the interior of the subducting oceanic lithosphere. a. True b. False
a. True
P and S waves do not follow simple paths as they pass through Earth they speed up, slow down, and change direction, and S waves even disappear when they reach Earth's core. a. True b. False
a. True
The biggest earthquake ever recorded instrumentally occurred on 22 May 1960 in southern Chile with a seismic moment magnitude of 9.8. a. True b. False
a. True
The biggest shaking event is called "the earthquake," the smaller ones before it is known as foreshocks, and the smaller ones after them are called aftershocks. a. True b. False
a. True
To describe the location in the three-dimensional space of a deformed rock layer or a fault surface, geologists make measurements known as dip and strike. a. True b. False
a. True
Aftershocks are smaller than the mainshock in an earthquake sequence. a. True b. False
b. False
Following the paths of P and S waves from Earth's surface inward, there is an initial increase in wave speed but then a marked slowing occurs at a depth of about 100 meters this defines the top of the lithosphere. a. True b. False
b. False
Normal faulting occurs when the hanging wall moves upward relative to the footwall. a. True b. False
b. False
The point where a fault first ruptures underground is known as the epicenter. a. True b. False
b. False
Which statement is TRUE? Earthquakes in California are: a. the result of reverse faulting along the San Andreas Fault. b. the result of widening along the San Andreas Fault, which will eventually cause western California to sink into the ocean. c. always above magnitude 7.5 because the San Andreas is such a large fault. d. shallow and occur in the upper 15 km of crust.
b. the result of widening along the San Andreas Fault, which will eventually cause western California to sink into the ocean.
The global occurrence of earthquakes reveals that: a. their locations are randomly scattered. b. they usually occur on the boundaries of plates. c. they usually occur at the center of plates. d. they prove that Earth is splitting apart (rifting) at all plate boundaries.
b. they usually occur on the boundaries of plates.
Which statement is TRUE? a. P, S, Love, and Raleigh are all body waves that pass through the Earth's interior. b. The hypocenter (focus) is the point on Earth's surface directly above the epicenter. c. Love waves travel faster than Raleigh waves d. S-waves travel twice as fast as P-waves.
c. Love waves travel faster than Raleigh waves
Three basic classes of collisions include all but which of the following? a. Oceanic plate versus oceanic plate b. Oceanic plate versus continent-bearing plate c. Continental plate versus continental plate d. Continental plate versus mantle plate
d. Continental plate versus mantle plate
The slide-past motions of strike-slip faults occur in all but which of the following? a. The North Anatolian fault in Turkey b. Along the San Andreas Fault in California with its famous earthquakes c. At the southwestern edge of the Pacific Ocean where the Alpine fault cuts across the South Island of New Zealand d. Where the Indian subcontinent touches Asia
d. Where the Indian subcontinent touches Asia
