How Cascadia Is At Risk: Societal Exposure to Future Earthquakes

CREW and other groups have developed various tools to understand how future earthquakes would affect different parts of the region and what communities stand to lose after an event. Emergency managers and policymakers must know which communities are vulnerable — and which assets each community is most afraid to lose — in order to effectively reduce risk and make communities more resilient after an event.

For example, coastal towns in the Cascadia region are generally vulnerable to a subduction zone earthquake and the tsunami that would follow. But some towns are more vulnerable than others because a higher percentage of the town’s residents, economic activity and community assets lie in the path of a potential tsunami.

CREW has published three reports, called scenarios, that describe the major types of earthquakes that occur in the Cascadia region. These scenarios explain how these earthquakes affect the region and the damage and losses that have occurred or could occur in the future.

Community exposure assessments are based on overlays of hazard and socioeconomic data to provide a first-approximation of possible losses. Exposure assessments have been completed for:

  • Earthquake scenarios in Washington
  • Cascadia tsunami hazards in Washington
  • Cascadia tsunami hazards in Oregon

Loss estimates are based on earthquake, soil, engineering and other information to generate feasible estimates. Loss estimates have been completed for:

  • Cascadia subduction zone
  • Earthquake scenarios in Washington

In addition, FEMA’s Hazus model is a loss estimation tool that can be used to determine the vulnerability of certain areas or facilities to earthquakes and related hazards. This information can be combined with local building data to generate feasible loss estimates. Estimates using Hazus have been completed for many areas in the Cascadia region and can be obtained through local and state emergency management agencies. Many regions also have Hazus User groups.