Transcript Glencoe Chapter 9

Glencoe Chapter 9
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Faults
• Rocks break and
move along surfaces
called faults.
Earthquakes
• Vibrations caused by
breaking of rocks
along faults.
Types of Faults
• Normal Faults:
– Force: Tension
– Direction: Apart
• Reverse Faults
– Force: Compression
– Direction: Together
• Strike-slip Fault:
– Force: Shearing
– Direction: Sliding
Normal Faults
Reverse Fault
Strike-Slip Fault
Seismic Waves
• Vibrations caused by
earthquakes.
Earthquake Focus
• The point in the Earth’s interior where the
is energy release occurs.
Primary Waves:
• Waves that move through Earth by causing
particles in rocks to move back and forth in
the same direction the wave is traveling.
Secondary Waves
• Move through Earth by causing particles in
rocks to move at right angles to the
direction of the wave.
Surface Waves
• Move by giving particles an elliptical
motion, as well as a back-and-forth
swaying motion.
Epicenter
• The point on Earth’s surface directly
above an earthquake’s focus.
Locating an Epicenter
1. S-P Interval: Take the difference in arrival
time of the primary and secondary waves.
2. Find the distance from the seismic station
and the epicenter. For 3 stations.
3. Plot the distances as radii on three
circles. Where they meet is where the
epicenter is located.
S-P Interval
Find Distance
Plot Epicenter
Seismologist
• Scientist who studies earthquakes.
Seismograph
• Instrument used to
measure the
vibrations caused by
earthquakes
A mile or so below you there are
large pieces of the Earth’s crust
known as __________________.
Plates
They move and float on a river of
______________ in the Earth’s
_______________.
Magma
Mantle
Where these plates break a
______________ will form.
Faults
At ______________ plate
boundaries ___________ forces
cause reverse faults to form.
Convergent
Compression
At transform plate boundaries
__________ forces cause
__________ faults to form.
Shearing
Strike-Slip
Lastly, as tension forces act on
the plates at
___________________ plate
boundaries, __________ faults
form.
Divergent
Normal
As plates interact they
sometimes produce large
vibrations known as __________.
Earthquakes
The _________ is the location
under the ground where the
energy of the vibrations was
released.
Focus
The point on the surface directly
above this location is known as
the ____________.
Epicenter
_____________, scientist who
study earthquakes use
instruments called
_______________ to measure
the vibrations caused by
earthquakes.
Seismologist
Seismograph
The first wave of energy released
by an earthquake is a
_______________ wave.
Primary
P-waves travel in a
_________ motion.
Side to Side
Second to arrive at the
_________ station is the
____________ wave
Seismic
Secondary
These waves travel in a
__________ motion.
Up and Down
The seismic wave that causes
the most damage is the
________________ wave.
Surface
Scientist read _____________ to
determine the difference in the
arrival time of the ___________
wave and the _____________
wave.
Seismograms
P-wave
S-wave
Once they have determined the
__________________ they use a
chart to determine the distance
the ____________ station was
located from the
_______________.
S-P interval
Seismic
Epicenter
The height of the _________ on
the paper tells the ___________
of the earthquake. __________
use the _________ scale to
measure the magnitude of
earthquakes.
Lines
Magnitude
Richter
Because the _______________
waves caused by earthquakes
move out in all directions,
scientist must have
measurements from __________
different __________ stations.
Seismic
3
seismic
Once they have the
measurements they use a
_____________ and plot the
distance as a radius out from
each seismic station.
Map
Where these circles cross the
_________________ of the
earthquake is located.
Epicenter
If a(n) ____________ takes place
under ________________ a
_______________ can take
place.
Earthquake
Water
Tsunami
This large wave can reach
_________ meters in height.
30
The ___________ plates that
make up the earth’s
___________ are on top of the
Earth’s ___________.
Tectonic
Crust
Mantle
Below the Mantle is the
_________ core and _________
core.
Outer Core
Inner Core
The ______ core is composed of
_________ and _________ and
is liquid.
Outer Core
Iron
Nickel
The _______ core is also
composed of __________ and
________ but is solid.
Inner
Iron
Nickel
The mantle is made mostly of
_______, __________,
_____________ and _________.
Magnesium
Silicon
Oxygen
Iron
______________ ___________
is the boundary between the
crust and mantle
Moho Discontinuity
___________ waves speed up
because they are passing into
the __________ which is the rigid
__________ and upper
______________.
Seismic
Lithosphere
Crust
Mantle