Hazards

This section can help educate communities about the array of potential coseismic hazards for the Pacific Northwest.

• Earthquakes
  An earthquake is a sudden trembling motion caused by an abrupt release or strain on the tectonic plates that form the earth's crust. Faults on or near the plate boundaries slip when the rock exceeds its elastic limit causing earthquakes.
  
  • Introduction
  • History
  • Future Risk
  • Amplification


• Tsunamis
  Tsunami is one or a series of huge sea waves caused by an earthquake, submarine earthquake, volcanic eruption, landslide, or other large-scale disturbance of the ocean floor. Sometimes referred to incorrectly as a tidal waves, tsunamis have nothing to do with tides. The word tsunami means "harbor wave" in Japanese.


• Ground Failure
  
  
  • Liquefaction -Liquefaction is a physical process in which saturated soils react to vibrations, lose their strength and stiffness, and act as viscous or jelly-like fluid. Earthquakes can cause the soil to liquefy.
  
  
  • Landslides - A landslide is the downward and outward movement of slope-forming material such as rocks, dirt, or mud due to gravity's forces. Earthquakes can trigger landslides causing severe damage to both the natural and man-made environment.
  
  
  • Subsidence - Subsidence is the loss of surface elevation due to the removal of subsurface support. For example, extensive mining in a place can cause subsidence to occur.


• Secondary Hazards

  Secondary hazards are triggered by an earthquake or seismic activity, and include such events as dam failures, fires, and oil or chemical spills.

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