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