Chapter 6-Study Questions
Multiple Choice:Select the best answer to complete the statement.
___1. The movements that cause earthquake vibrations are usually associated with large fractures called _____.
a. domes b. anticlines c. faults d. tsunamis
e. seismograms
___2. Which of the following is true of P waves?
a. stopped by liquid b. greatest velocity
c. compression wave d. a and c e. b and c
___3. Which one of the following lists the order in which earthquake waves will be recorded by a seismograph located several hundred kilometers from an earthquake epicenter?
a. P,S, surface b. S,P, surface c. surface, S,P
d. surface, P,S, e. P, surface, S
___4. Each unit of magnitude increase on the Richter scale equates to roughly how much of an increase in the energy released?
a. 2-fold b. 10-fold c. 15-fold d. 20-fold e. 30-fold
___5. Seismic sea waves are also called_____.
a. swells b. tsunami c. breakers d. surf
e. currents
___6. The zone in the upper mantle consisting of hot, weak rock that is easily deformed is the _____.
a. lithosphere b. hydrosphere c. shadow zone
d. crust e. asthenosphere
___7. The rigid layer of Earth, which includes the crust as well as the uppermost mantle, is the _____.
a. lithosphere b. hydrosphere c. shadow zone
d. asthenosphere e. outer core
___8. Dip-slip faults in which the hanging wall moves down relative to the footwall are called _____ faults.
a. strike-slip b. normal c. reverse d. complex
e. oblique-slip
___9. Faults in which the dominant displacement is along the trend of the fault are called _____ faults.
a. strike-slip b. normal c. reverse d. complex
e. oblique-slip
___10. A chaotic accumulation of sedimentary and metamorphic rocks with occasional scraps of ocean crust scraped from a subducting plate and found on the landward side of an ocean trench is called a(n) _____,
a. fault b. dome c. plateau d. hot spot
e. accretionary wedge
True/False
___11. The actual place of origin of an earthquake within Earth is called the epicenter, while the location on Earth’s surface directly above is called the focus.
___12. Small earthquakes that precede a major earthquake are called foreshocks, while adjustments that follow a major earthquake often generate smaller quakes called aftershocks.
___13. The four major zones of Earth’s interior, from the surface to the center, are the lithosphere, mantle, outer core
inner core.
___14. Synclines are upfolded rock layers that form from the bending of previously flat-lying sedimentary and volcanic rocks.
___15. Most major mountain ranges form along convergent plate boundaries.
___16. Most of the motions that produce earthquakes can be satisfactorily explained by the plate tectonics theory.
___17. The slow, gradual displacement, with little noticeable seismic activity, along a fault is known as fault creep.
___18. Where unconsolidated materials are saturated with water, earthquakes may produce a phenomenon known as liquefaction.
___19. At least a portion of Earth’s outer core is liquid because S waves cannot propagate through it.
___20. Tensional stresses shorten and thicken the crust.