Earthquakes
Deformation
• The process of when a rock changes
because of stress
– Compression-rocks push together
(squeezing)
– Tension-rocks pull away from each other
(stretching)
– Rock layers bend when stress is placed
on them. But when the stress is placed
on rocks, they can reach their elastic limit
and break
Folding
• Bends in rock that are the result of
heat and pressure
– Occur when the pressure is not great
enough to break the rock
– Mountain form when tectonic plates
collide
Fault- A break in rock that is due to
stress
When rocks
are pulled
apart
When rocks
are pushed
together
When rocks
are moved
horizontally
Seismology
• The study of earthquakes
– Seismologist-a scientist who studies
earthquakes
– Seismograph- used to record vibrations in earth
and determine the strength of an earthquake
– Seismogram- a tracing of earthquake motion
• Earthquake-a sudden, violent shaking of
the Earth caused by a shifting of the
Earth’s crust
Seismic Waves- a wave of energy that travels
through the earth (also called Body Waves)
P Waves
• Pressure/Primary Waves
• Fastest waves
• Travel through liquid, solid
or gas
• Move rock back and forth
which squeezes and
stretches the rock
S Waves
•
•
•
•
Shear/Secondary Waves
Second fastest
Travel through solids
Shear rock side to side as
they travel through the rock
http://www.classzone.com/
books/earth_science/terc/c
ontent/visualizations/es100
2/es1002page01.cfm
Surface Waves
• Move along the earth’s surface
• Travel more slowly and are
more destructive
• Move the ground much like
ocean waves move water
particles
• Epicenter- the point on the earth’s surface
directly above an earthquakes starting
point
• Focus-the point inside the Earth where an
earthquake begins
• Richter Scale- used to measure the
strength of earthquakes
Create a circle map about Earthquakes
• Earthquake Causes
– http://www.youtube.com/watch?v=P53OJd_lxew
• Earthquake Destruction
– http://www.youtube.com/watch?v=CtBXTvtFaCU
• Study Jams: Earthquakes
– http://studyjams.scholastic.com/studyjams/jams/science/rocksminerals-landforms/earthquakes.htm
• Mr. Parr It’s An Earthquake
– http://www.youtube.com/watch?v=sA6oZ4YgKCA