Download Earthquakes 091216

Charleston Earthquake – 1886 (7.6)
Earthquakes close to home…
South Carolina Earthquake – Live!
What can we hypothesize about where the Earthquakes
happen often and close together?
Earthquakes close to home…
EARTHQUAKES 101
Real-Life Earthquake Footage
8.2 magnitude, Chile, 2011
REFLECTION
Why do scientists care about what
makes them happen?
Why do WE care about what makes
them happen?
What is the importance of knowing where
earthquakes can occur?
What is an EARTHQUAKE?
Earthquakes are produced when rocks break along a
fault.
The term earthquake describes the sudden slip on a fault
and includes the ground shaking and radiating seismic
energy that is caused by the slip. What can cause
EARTHQUAKES to occur?
Tectonic plates move past each other causing STRESS.
Stress causes the rock to collapse.!
This happens at:!
1. 
Convergent Boundaries!
2. 
Divergent Boundaries!
3. 
Transform Boundaries!
4. 
Faults !
What can cause
EARTHQUAKES to occur?
1. Earthquakes occur along plate boundaries where
pressure builds up and forms fault lines!
• 
When the pressure is released, an earthquake occurs
along the fault line!
2. Earthquakes can also occur along faults!
What can cause
EARTHQUAKES to occur?
Stronger earthquakes
are more likely to
occur along active
plate boundaries.
Strong earthquakes
are more common at
transform and
convergent plate
boundaries.
Parts of an Earthquake
• 
FAULT: a break in the rock of the
earth’s crust or mantle where an
earthquake begins
• 
FOCUS: the point below the Earth’s
surface that an earthquake’s
energy is released from
• 
EPICENTER: the point on the
Earth’s surface directly above the
focus where the earthquake’s
energy is the greatest
• 
SEISMIC WAVES: Vibrations of
energy that spread outwards from
the focus of the earthquake
What Kind Of Damage Can
Earthquakes Cause?
• 
There is evidence to support the idea that tectonic
activity (earthquakes, volcanoes, etc.) contributed to
the demise (failure/death) of ancient civilizations.
• 
Based on the locations of current population centers,
scientists have developed models that show that
populations today may be just as vulnerable to the
aftereffects of powerful earthquakes.
• 
Earthquakes can even cause giant waves called
TSUNAMIS.
EARTHQUAKES AND PEOPLE
• 
Many population centers are located near active
fault zones and/or active plate boundaries such
as the San Andreas Fault.
• 
Millions of people in these population centers
have suffered personal and economic (money)
losses due to volcanic and earthquake activity.
• 
When exposed to sudden lateral (side-to-side)
forces earthquakes buildings and bridges can
collapse, crushing the people in and around
them.
EARTHQUAKES AND PEOPLE
• 
Many cities now have a lot of very tall buildings.
This can pose a huge problem if an earthquake
occurs.
• 
Luckily over the past few decades (decade=10
years), architects and engineers have developed
technologies to help these tall buildings bend
instead of break.
• 
Because of these flexible buildings, the chances
for survival of the people in them is greatly
increased!
EARTHQUAKES AND PEOPLE
Exit Ticket
1. What causes earthquakes to occur?
2. Where do earthquakes occur the
most?
3. What are the 4 places Earthquakes
can occur at?
4. Why is it important to study WHY and
HOW Earthquakes occur?
Seismic Waves
• 
Primary Wave (P - Wave)!
• 
Secondary Wave (S - Wave)!
• 
Surface Wave (L - Wave)!
Primary Waves
• 
Travel through ALL layers of the Earth
(solid and liquids)!
• 
Travel in a straight line (back and
forth)!
Secondary Waves
•  ONLY
travel through solids!
•  Travel
side to side and up and down!
Slinky = Seismic Waves
• 
You will use the slinkys
to demonstrate how the
waves move.!