Evaluating Earthquakes

Evaluating Earthquakes
Jill Frank
September 2006
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Abrupt shakings of the Earth
caused by the release of
built up pressure on the
Earth’s surface.
 Earthquakes cause the Earth
to shake for less than a
minute but can do major
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Is the Earth’s Crust
One Solid Sheet?
The crust of Earth is actually broken
into 12 main plates that fit together
like puzzle pieces.
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The Floating Earth
The mantle is the layer of Earth just below
the crust. It is a made up of a liquid.
 Because the mantle is liquid, the hard
surface of the Earth is actually floating.
 The crust floating on the mantle is similar to
crackers floating on top of soup.
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Who’s Fault is it?
The space between two plates is called a fault.
 Because earthquakes occur when two plates
rub together, they are often said to occur on
fault lines.
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Plate Movement
Earth’s plates can move in three
– Divergent
– Convergent
– Transformational
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This movement
forms an
How Does an Earthquake Form?
When plates try to move in opposite directions,
they put pressure on each other because they do
not want to slide past each other.
 When the pressure gets too great the pressure
breaks and the plates are forced to slide. This
sliding, called friction, is rough and jerky which
causes the Earth to shake.
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The Center of it All
The point where the plates experience
the friction is called the epicenter.
 Where is the epicenter in this picture?
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Who Feels the Shaking?
The shaking starts at the epicenter and
spreads in circles outward much like the
ripples of water dripping into a puddle.
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Seismic Waves
The waves of shaking are called seismic
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The Richter Scale
The Richter scale is used to measure
how much shaking an earthquake causes.
 The Richter scale gives each earthquake
a number from 1-10.
– Less than 2 – cannot be felt
– 2 and 4 – can be felt but do not cause
– 5 and 6 – can cause damage
– 7-10 are major earthquakes and cause
severe damage
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How Do We Measure An
Earthquakes are measured using a
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A Homemade Seismometer
As the Earth shakes it causes the cup
and pencil to swing drawing lines on the
Would a major earthquake make big
lines or small lines?
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Earthquake Damage
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Does Mississippi Have
Yes, but they are very rare.
 In 1812 an earthquake of 8.2 magnitude
was recorded in Memphis, TN. Mississippi
felt the shaking.
 It is predicted that this fault will produce
another quake in the next 50 years.
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Works Cited
Berkley. 1995. Earthquake. Accessed 20 Sept. 2006.
CDLI. Earthquakes: seismic waves. Accessed 20 Sept. 2006.
ETI. 2006. Sniffing for oil and earthquakes. Accessed 20 Sept. 2006. http://www.etigeochemistry.com/gulfeq/images/pic07.html
FEMA. Earthquakes. Accessed 20 Sept. 2006. http://www.fema.gov/kids/quake.htm
Live Science. New Data Confirms Strong Earthquake Risk to Central U.S. Accessed 20
Sept. 2006. http://www.livescience.com/forcesofnature/050622_new_madrid.html
Maps. 2006. Earth’s tectonic plates. Accessed 20 Sept. 2006.
Maryland Geological Society. 2006. Earthquakes. Accessed 20 Sept. 2006.
Nana’s Recipes. Accessed 20 Sept. 2006. http://nanasrecipes.com/soup.html
North Mississippi GK-8. Earthquake activites. Accessed 20 Sept. 2006.
Physical Geography. 2006. Earthquakes. Accessed 21 Sept. 2006.
Provincial Emergency Program. 2006. Earthquake damage. Accessed 20 Sept. 2006.
The Tech. Earthquakes. Accessed 20 Sept. 2006.
Thinkquest. Earthquakes. Accessed 20 Sept. 2006.
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