Good Friday Alaskan Earthquake

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Good Friday Alaskan Earthquake
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8.3 Destruction from Earthquakes

• Damage to buildings and other structures from
  earthquake waves depends on
• Intensity and duration of the vibrations
• The material on which the structure is built
• The design of the structure.

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8.3 Destruction from Earthquakes
? Building Design
Factors that determine structural damage

• Stone or brick buildings are the most serious
  safety threats
• Steel is better than stone or brick

- Nature of the material upon which the
structure rests- sands are the worst
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Earthquake Damage
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Earthquake Design
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8.3 Destruction from Earthquakes
? Liquefaction
Saturated soil material turns fluid
Underground objects may float to surface
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Effects of Subsidence Due to Liquefaction
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8.3 Destruction from Earthquakes
? Cause of Tsunamis
A tsunami occurs when the vibration of a quake
sets an underwater landslide into motion.
Tsunami is the Japanese word for seismic sea
wave.
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Movement of a Tsunami
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8.3 Destruction from Earthquakes
? Landslides
With many earthquakes, the greatest damage to
structures is from landslides and ground
subsidence, or the sinking of the ground
triggered by vibrations.
? Fire
In the San Francisco earthquake of 1906, most
of the destruction was caused by fires that
started when gas and electrical lines were cut.
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Landslide Damage
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Fire Resulting from an Earthquake