Tsunami Inundation Modeling of San Juan Islands, Washington, due to a Cascadia Subduction Zone Earthquake

Tsunami inundation modeling for the coastal areas of the San Juan Islands, Washington, due to a great earthquake along the Cascadia subduction zone was conducted using a single earthquake source scenario and a high-resolution inundation model. Simulated results showed that the initial tsunami wave peak hits the southern coast of the San Juan Islands more than 1.25 hours after the earthquake, with tsunami flow depths higher than 3 meters occurring at certain coastal areas. The simulation also showed high current speeds in channels between the islands. The results of this study can be used to enhance the State of Washington’s mitigation efforts for the San Juan Islands.