Transcript What`s shaking??? Earthquakes

What’s shaking???
S6E5. Students investigate
how the Earth’s surface is
formed
EARTHQUAKES
Def: the vibrations
caused by the
breaking of rock
within Earth
Where do
earthquakes
happen?
Along faults
(breaks in Earth’s crust)
What causes Faults?
–The movement of plates
puts stress on rocks
–After a lot of force, the
rocks break and move
along the faults
What are the 3 main
types of faults?
1 – Normal Faults
2 – Reverse Faults
3 – Strike-Slip Faults
(Earthquakes!)
How do earthquakes
occur?
• Pressure builds up and
stresses the rocks
• The rock breaks and
moves along the fault
Types of faults
depend on the
plate boundaries
and the stress
that moves the
rock of the
lithosphere.
Most stress is at boundaries
where plates meet
because…
The edges of the plates along
faults catch against each
other, lock up, stop the
movement, and stress builds
up!
What are seismic
waves?
Waves of energy
generated by an
earthquake that travel
through earth.
What is the epicenter of
an earthquake?
The point directly above the
earthquake focus is the
epicenter or where the
earthquake began.
Seismic
Waves
The FOCUS is the area beneath
Earth’s surface where rock that is
under stress breaks, triggering an
earthquake.
By predicting where an
earthquake is likely to
happen…
People can plan their
houses to be farther
away and/or build
seismic-safe structures
• Richter Earthquake Magnitudes Effects:
Less than 3.5 Generally not felt, but
recorded.
3.5-5.4 Often felt, but only minor damage.
5.5-6.0 Slight damage to buildings.
6.1-6.9 Can be destructive in areas where
people live.
7.0-7.9 Major earthquake. Causes serious
damage.
8 or greater Great earthquake. Total
destruction to close communities.
Earthquake Facts & Games
• http://earthquake.usgs.gov/learn/facts.php
• http://earthquake.usgs.gov/learn/kids/
• http://environment.nationalgeographic.com
/environment/naturaldisasters/earthquake-profile.html
What happens if
there is an
earthquake in the
ocean?
Tsunamis
A TSUNAMI…
HUGE ocean waves
created by
earthquakes that can
destroy everything in
the path.
Earthquake Resources:
• http://www.ecs.csun.edu/~shustov/ShakeZ
one.htm
• http://tlc.discovery.com/convergence/quak
es/interactives/makeaquake.html