Transcript Earthquake Hazards - Paramus Public Schools

Do Now – In Notebooks


What are some effects of earthquakes?
Why is intensity not always the same as magnitude
for an earthquake?
EARTHQUAKE
HAZARDS
How can earthquakes affect society?
Structural Failure

Stone and concrete
 Easily

damaged
Wooden structures
 Withstand
Earthquakes
Better

Steel-framed buildings
 High
rises are
reinforced to make them
earthquake resistant
Structural Failure
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“Pancaking”
 Supporting
above falls
walls of a building fail and an intact level
Aftershocks

A ground tremor caused by the repositioning of
rocks after an earthquake
Land and Soil Failure

Massive landslides
 Earthquakes
liquefy
surface materials which
then behave like
quicksand

Greatest damage in
soft soil
Earthquake Evidence

Fault scarps
 Areas
of great vertical offset
Tsunami

A tsunami is a series of water waves generated by a
disturbance in the ocean.
How do Tsunamis form?
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Tsunami sources displace water in the ocean
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Gravity then acts to restore displaced water
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A wave is generated that travels as an expanding
ring across the ocean’s surface
Earthquake Forecasting
Calculating the probability of an earthquake
 Done by following:
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 History
of Earthquakes in an area
 Rate at which strain builds up in the rocks
Where do Earthquakes Occur?
Earthquakes are not randomly distributed
 Majority of earthquakes occur along seismic
belts (Almost 80% at Circum-Pacific Belt)
 Seismic gaps

 Place
along an active fault that has not
experienced an earthquake for a long time