Cascadia Subduction Zone map (IMAGE) University of Texas at Austin Caption The Cascadia Subduction Zone is located just offshore of the Pacific Northwest of North America and has a history of generating powerful earthquake. Credit National Oceanic and Atmospheric Administration Usage Restrictions No restrictions. License Public Domain Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.