chapter 6: restless earth

which one of the following statements is true about the crust?

It is the thinnest of the major subdivisions.

which kind of seismic wave is fastest moving?

P waves

major earthquakes are often followed by somewhat smaller events known as

aftershocks

the richter magnitude of an earthquake is determined from the __________.

amplitude of the largest seismic wave

the distance between a seismological recording station and earthquake source is determined from the ________.

arrival times of P and S waves

________ is when a rock "snaps back" to its original stress-free form after an earthquake.

elastic rebound

the position on earths surface directly above the earthquake source is called the ________.

epicenter

when an earthquake occurs, energy radiates in all directions from its source. the source is also referred to as the __________.

focus

which of the following is determined by making direct observations in the area affected by an earthquake?

intensity

Earths core is interpreted to consist mainly of ______.

iron and nickel

the __________ is the cool, brittle, outer layer of Earth that includes the crust and uppermost mantle.

lithosphere

on a typical seismogram, _________ will show the highest amplitudes

surface waves

which kind of seismic wave is responsible for the shaking (and thus, the most damage to human structures)?

surface waves

Seismologists use a method called ________ to pinpoint the epicenter of an earthquake by using three or more seismic stations.

triangulation

a rapidly moving ocean wave generated by an earthquake that is capable of inflicting heavy damage in coastal regions is called a(n) ________.

tsunami

a tsunami can occur __________.

when an earthquake occurs in the seafloor like along an oceanic plate boundary

oceanic crust is composed primarily of ________.

basalt

how did the himilayas form?

collision of India and Eurasia

Most orogenesis occurs along ________ plate boundaries.

convergent

the collective term for any process that produces a mountain belt is called ______.

orogenesis

the ______________ is a layer in Earth's interior that is in a liquid state.

outer core

__________ occur in which the hanging wall block moves up relative to the foot wall block.

reverse faults

our greatest source of knowledge about earth's interior comes from _______.

seismic waves

The record of an earthquake obtained from a seismic instrument is a(n) ________.

seismogram

a ______ is an instrument that is used to record earthquake vibrations.

seismograph