Transcript Earthquakes

Earth’s Crust in Motion
• When the Earth’s plates are in motion,
earthquakes may occur.
• Tier Word
• Motion-movement
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STRESS
• The movement causes stress in the crust.
• There are 3 types of stress in the crust
• Stress -pressure
Musical sliders
Tensional Stress
(gum)
Compressional Stress
What happens during an
earthquake?
• The stress builds and then releases. This
is the energy in an earthquake.
• An earthquake is the shaking and
trembling that is caused by the movement
of rock beneath Earth’s surface.
Faults
• Earthquakes are caused by stress at fault
lines.
• A fault line is found at the boundaries of
two different lithospheric plates.
• (it’s the faults fault! )
• haaaaaaaaaaaa
Strike slip fault
• Caused by shearing
• Rocks slip past each other
• San Andreas Fault
• Normal faults -the land is pulling apart or
stretching.
• The tension in the crust increases until the
rocks fracture.
• One block of land slips downward
•
Fracture-break
Reverse
Forms by compression
hanging wall slides up and over
footwall
Formed Appalachian Mountains
(Thrust)
Fault
• http://www.iris.edu/gifs/animations/faults.ht
m
• http://science.howstuffworks.com/nature/n
atural-disasters/earthquake3.htm
Safety Tips
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Have an earthquake readiness plan.
make your home sturdier, such as bolting bookcases to wall studs, installing
trong latches on cupboards, and strapping the water heater to wall
Locate a place in each room of the house that you can go to in case of an
earthquake. It should be a spot where nothing is likely to fall on you.
Keep a supply of canned food, an up-to-date first aid kit, 3 gallons (11.4
liters) of water per person, dust masks and goggles, and a working batteryoperated radio and flashlights.
Know how to turn off your gas and water mains.
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Mountain Building
• Takes millions of years
• Caused by compression/converging
forces
• Formed by folding –bends in rock that
form when compression shortens and
thickens part of Earth’s crust
Mountain Building Cont.
• Syncline
• Anti-cline
• Plateau
dip
=
peak
rock bends into an arch
=large area of flat land
elevated high above sea
level
Colorado Plateau
Folding
upward fold
Syncline
Syncline
folded arched rock
Anti-Cline-fold
Tier words to Know for the Test
and Beyond
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Compress -squeeze
Geologic event (earthquakes, volcanoes)
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Interior-inside
Motion -movement
Anything that starts with the prefix geo-earth
Volcanologist- studies volcanoes
Seismologist- studies earthquakes
Diverge -separate
Converge- come together
Transform- slip past
Stress –pressure/tension
Students Stop Here
Teacher notes
Questions to Think About
Essential Questions:
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Can we predict earthquakes? Can we predict when
volcanoes will erupt?
• What do earthquakes and volcanoes tell us about what
is happening inside the earth and on the surface?
• Do you have to worry about a volcanic eruption or
• earthquake where you live? Why or why not?
What students need to know for
the long run
– Unit Enduring Understandings:
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Studying historical earthquakes and volcanic eruptions improves our
understanding of earth's processes.
– Although it is known where earthquakes and volcanic eruptions are likely to
happen, there is currently no reliable way to predict precisely when an event will
occur.
– Volcanoes and earthquakes indicate the high temperatures and pressures that
exist in earth's interior.
– Volcanism(volcanic activity) and seismic(earthquake) activity vary across the
globe
Common misunderstandings
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What do students typically misunderstand?
Earthquakes don’t only occur when whole plates slide past each other.
Earthquakes don’t create a gap or hole in the earth's surface.
Earthquakes don’t occur at one depth.
Lava that erupts out of a volcano does not comes from earth's core.
Earthquakes don’t cause volcanic eruptions.
Plate boundaries are not the same as faults.
Lava does not come out of all volcanic eruptions