Chapter 6 test questions

Faults where the movement is primarily vertical are called _____ faults. a. transform b. oblique c. dip-slip d. random e. strike-slip

c. dip-slip

The location on the surface directly above the earthquake focus is called the _____. a. ephemeral b. epicycle c. epicenter d. epinode e. epitaph

c. epicenter

Dense rocks like _____ are thought to make up the mantle and provide the lava for oceanic eruptions. a. limestone b. granite c. peridotite d. sandstone e. rhyolite

c. peridotite

Dip-slip faults are classified as _____ faults when the hanging wall moves up relative to the footwall. a. normal b. transform c. reverse d. tensional e. strike-slip

c. reverse

The study of earthquakes is called _____. a. seismogram b. seismicity c. seismology d. seismography e. seismogony

c. seismology

Where two oceanic plates converge _____ subduction zones often occur. a. Andean-type b. Himalaya-type c. American-type d. Aleutian-type e. Arctic-type

d. Aleutian-type

The rock immediately above a fault surface is commonly called the _____. a. anticline b. foot-wall c. syncline d. hanging wall e. dip-slip

d. hanging wall

The farther a station is from an earthquake

the greater the difference in arrival times of the P and S waves.,True

Vibrations known as earthquakes occur as rock slips and elastically returns to its original shape.

true

A refined Richter scale is used to describe earthquake magnitude.

True

Earth's inner core is a solid metallic sphere.

True

Earthquake body waves are divided into two types called primary (P) waves and secondary (S) waves.

True

Earthquake waves that travel through Earth's interior are called body waves.

True

Most earthquakes occur along faults associated with plate boundaries.

True

Most folds result from compressional stresses in the crust.

True

Most of our knowledge of Earth's interior comes from the study of earthquakes.

True

No reliable method of short-range earthquake prediction has yet been devised.

True

Strike-slip faults that are associated with plate boundaries are called transform faults.

True

The continental crust is mostly made of granitic rocks.

True

The epicenter of an earthquake is the location on the surface directly above the focus.

True

The mantle is solid because both P and S waves travel through it.

True

To locate an epicenter the distance from three or more different seismic stations must be known.

True

An earthquake with a magnitude of 6.5 releases _____ times more energy than one with a magnitude of 5.5. a. 10 b. 20 c. 30 d. 40 e. 50

c. 30

Which one of the following mountain ranges has formed where continental crusts have converged? a. Sierra Nevada b. Andes Mountains c. Himalaya Mountains d. Coast Ranges

c. Himalaya Mountains

The San Andreas fault zone separates two great sections of Earth's crust the North American plate and the _____ plate. a. Nazca b. Juan de Fuca c. Pacific d. Philippine e. South American

c. Pacific

The boundary that separates the crust from the underlying mantle is known as the shadow discontinuity.

False (Mohorovicic)

The lithosphere is situated below the asthenosphere.

False (above)

The adjustments that follow a major earthquake often generate smaller earthquakes called foreshocks.

False (aftershocks)

P waves arrive at a recording station after S waves.

False (before)

Fluids (gases and liquids) cannot transmit P waves.

False (can)

Most major episodes of mountain building have occurred along divergent plate boundaries.

False (convergent)

Earthquakes in the central and eastern United States occur more frequently than along plate-boundary areas.

False (less)

The study of earthquakes is called seismography.

False (seismology)

Earthquakes with a Richter magnitude less that eight are usually not felt by humans.

False (two)

Most tsunamis result from horizontal displacement of the ocean floor during an earthquake.

False (vertical)

Where oceanic crust is being thrust beneath a continental mass _____ subduction zones often occur. a. Andean-type b. Himalaya-type c. American-type d. Aleutian-type e. Arctic-type

a. Andean-type

5. Which earthquake body wave has the greatest velocity? a. P wave b. S wave

a. P wave

It is assumed that many of the terrains found in the North American Cordillera were once crustal fragments scattered throughout the eastern _____ ocean basin. a. Pacific b. Atlantic c. Indian

a. Pacific

The belt from about 105 to 140 degrees away from an earthquake where no P waves are recorded is known as the _____. a. shadow zone b. absent zone c. Moho zone d. reflective zone e. low velocity zone

a. shadow zone

The epicenter of an earthquake is located using the distances from a minimum of _____ seismic stations. a. three b. four c. five d. six e. seven

a. three

Which of the earthquake body waves cannot be transmitted through fluids? a. P waves b. S waves

b. S waves

The adjustments of materials that follow a major earthquake often generate smaller earthquakes called _____. a. tremors b. aftershocks c. foreshocks d. surface waves e. body waves

b. aftershocks

Earthquake epicenters are most closely correlated with _____. a. continental interiors b. plate boundaries c. population centers d. continental shelves e. high latitudes

b. plate boundaries

The two most common types of folds are anticlines and _____. a. domes b. synclines c. basins d. superclines e. batholiths

b. synclines

The difference in _____ of P and S waves provides a method for determining the epicenter of an earthquake. a. magnitudes b. velocities c. sizes d. modes of travel e. foci

b. velocities

In areas where unconsolidated materials are saturated with water earthquakes can turn stable soil into a fluid during a phenomenon called _____. a. libation b. lithification c. leaching d. liquefaction e. localization

d. liquefaction

It is estimated that over _____ earthquakes that are strong enough to be felt occur worldwide annually. a. 500 b. 1000 c. 10000 d. 20000 e. 30000

e. 30000

The source of an earthquake is called the _____. a. fulcrum b. ephemeral c. epicenter d. foreshock e. focus

e. focus

The cool rigid layer of Earth that includes the entire crust as well as the uppermost mantle is called the_____. a. asthenosphere b. lower crust c. oceanic crust d. Moho e. lithosphere

e. lithosphere

Long-range earthquake forecasts are based on the premise that earthquakes are _____. a. random b. destructive c. fully understood d. always occurring e. repetitive

e. repetitive