Reducing Tsunami Hazards along U.S. Coastlines

Abstract

On April 25–26, 1992, a swarm of large earthquakes rattled northern California, injuring 98 people and causing $66 million dollars in damage. The swarm began with a Ms 7.1 thrust earthquake that generated a small tsunami recorded at tide stations in California, Oregon, and Hawaii. This earthquake/tsunami event provided importalt evidence that the Cascadia Subduction Zone is seismically active and that tsunamis are likely from earthquakes occurring along the zone. This new evidence also led the National Oceanic and Atmospheric Administration (NOAA), the U.S. agency responsible for tsunami warnings, to evaluate the state of tsunami preparedness for communities potentially affected.NOAA conducted workshops on tsunami hazard assessment, tsunami warnings, and public education over a 15-month period. Over 50 tsunami scientists, emergency planners, and educators participated and produced technical reports with findings and recommendations. The most significant findings that emerged from these workshops include: 1. Technology exists to produce tsunami inundation maps for emergency preparedness. 2. Technology exists to issue tsunami warnings within 5 minutes for earthquakes occurring along U.S. coastlines. 3. Technology exists to detect tsunamis in the offshore ocean. 4. Tsunami education for local and distant tsunami is deficient for west coast decision makers and residents. A summary of the three workshops is presented in this report, along with 12 recommendations that participants felt would mitigate U.S. tsunami hazards.KeywordsTsunami WaveCoastal CommunityFederal Emergency Management AgencyTsunami HazardTsunami WarningThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.