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.