2. Basic Background Information
What is an earthquake?
An Earthquake is what happens when two blocks of
Earth suddenly slip or crack past eachother.
How are earthquakes measured?
Earthquakes are measured in Seismic Waves
measured by Seismographs.
What does magnitude mean?
The size of an Earthquake is called its Magnitude
How is magnitude measured?
Magnitude is measured by the size of their Seismic Waves.
3. Damage Caused by Earthquakes
Buildings suddenly collapse
Tsunamis begin to occur
Buildings shake and shutter
4. Waves
What are earthquake waves called?
Seismic Waves
What two types of seismic waves are there?
Primary and Secondary Waves
What two types of body waves are there?
Love and Rayleigh Waves
5. Body Waves
How do P waves travel?
They push and they pull
How do S waves travel?
They travel side to side, and up and down.
Which move faster?
P-waves move faster.
6. Elastic Rebound
A mechanism used by Geolgists to
explain Earthquakes and suface
ruptures.
The Elastic Rebound occurs in Divergent
Boundaries
7. The Tohoku Earthquake
This quake occurred at :
5:30 PM
This quake occurred
In Honshu, Japan.
The magnitude of this quake was
9.0
8. Effects on the environment/earth
• Nuclear Wastes from
Power Plants escape
into the evironment
• Many cities and
Humans are heavily
damaged
• Large cracks and
sinkholes .
9. Effects on the People of Japan
• People do not have
power from destroyed
power plants.
• Tsunamis flood cities in
Japan.
• Houses and buildings
are toppled over.
10. Effects on the Economy of Japan
• Many offices shut down
and people lost jobs.
• Food and water
become scarce and
polluted.
• Fires burn down
buildings and kill
hundreds.
11. GPS Sensors
• One interesting fact about this earthquake is that it
moved several GPS sensors. This will require all of
the GPS sensors to be rearranged.
• How does elastic rebound explain this movement?
Because the boundaries at the Elastic Rebound
point shifted, moving Japan.
12. Tsunamis
• What is a tsunami?
A giant wave usually caused by an earthquake.
• How do tsunami waves appear at sea?
After an earthquake hits, the waves cause the water to rise up and
move.
• How high can tsunami waves be?
About 50 to 250 feet high.
• How fast can tsunami waves move?
One hundred MPH in deep ocean water.
