8 and 9 review answers

A fault is ?
Faults are fractures in Earth where movement has occurred
An earthquake epicenter is ?
The epicenter is the location on the surface directly above the focus
When an earthquake occurs energy radiates in all directions from its source which is called the ?
Focus
Earthquakes are usually associated with ?
Large fractures in earths crust and mantle called faults
What causes earthquakes ?
Earthquakes occur due to the release of built up energy
Most earthquakes are produced by the rapid release of elastic energy stored in rock subjected to great forces ?
Elastic energy
During an earthquake the ground surface
Can move in any direction
The adjustments of materials that follow a major earthquake often generate smaller earthquakes called
Aftershocks
Major earthquakes are sometimes preceded by smaller earthquakes called
Foreshocks
The slow continuous movement that occurs along what fault ?
San Andreas fault
Which seismic waves travel most rapidly ?
P waves
What is true about p waves ?
They compress and expand rocks in the direction the waves travel
Overall which seismic waves are the most destructive?
The surface waves are because surface waves move in an up down side to side motion
What is the minimum number of seismic stations that is needed to determine the location of an earthquakes epicenter ?
Three
What instrument records earthquake waves?
seismograph
How much of an increase in wave amplitude is seen from an earthquake measuring 5.4 on the Richter scale compared to one measuring 4.4 ?
10 times greater
A succession of ocean waves set in motion by a submarine earthquake is called an ?
Tsunami
In areas where unconsolidated sediments are saturated with water,earthquakes can turn stable soil into fluid through a process called ?
Liquidfaction
Violent shaking from an earthquake can cause soil and rock on slopes to fail and cause a ?
Landslide
Why do earthquakes often cause damaging fires ?
The fires started when gas and electrical lines were cut
Long range earthquake forecast are based on the idea that earthquakes are ?
Repetitive or cyclical
What layers of earth make up the lithosphere ?
Crust and uppermost mantle
Through which Earth layer are S waves NOT transmitted ?
outer core because it is liquid
Earths core is made of an alloy of ?
iron,nickel
Wegners continental drift hypothesis stated that all continents once joined together to form ?
A single continent
The supercontinent in the continental drift hypothesis is called ?
PANGAEA
In the plate tectonics theory the lithosphere is divided into
plates and plates can be made up of both continental and oceanic lithosphere
A tectonic plate consists of
crust and uppermost mantle
A divergent boundary at two oceanic plates can result in a ?
Rift valley
What type of boundary occurs where two plates move together,causing one plate to descend into the mantle beneath the other plate ?
Convergent boundaries
Give an example of a transform boundary ?
San Andres fault
What occurs when divergence occurs between two oceanic plates ?
seafloor spreading
The Himalayas in south asia are an example of what type of plate boundary ?
Continental-continental
Volcanic island arcs are associated with what type of plate boundary ?
Oceanic-oceanic
Which of the following affects the amount of destruction caused by earthquake vibrations ?
The design of the structure,the intensity and duration of the vibrations,the nature of the materials on which structures are built
What hypothesis states that the continents were once joined to form a single continent ?
Continental drift
One kind of evidence that supports Wegener’s hypothesis is that ?
Fossils of the same organisms have been found on different continents
How did opponents of continental drift account for the existence of similar fossils on widely separated ?
Migration across land bridges
Which of the following statements correctly describes the asthenosphere ?
It permits plate motion
In the plate tectonics theory the lithosphere is divided into ?
7 major plates and many smaller plates
A tectonic plate consists of ?
crust and uppermost mantle
In the plate tectonic theory a plate can be made up of ?
both continental and oceanic lithosphere
A divergent boundary at two oceanic plates can result in a ?
rift valley
What type of boundary occurs where two plates move together causing one plate to descend into the mantle beneath the other plate ?
Convergent boundary
Which of the following is a geographic example of a transform fault boundary ?
the san andreas fault
New ocean crust is formed at ?
divergent boundaries
Which of the following results when divergence occurs between two oceanic plates ?
seafloor spreading
The Himalayas in South Asia are an example of what type of plate boundary ?
Convergent continental-continental boundary
Volcanic island arcs are associated with what type of plate boundary ?
convergent oceanic-oceanic boundary