On average, the Cascadia subduction zone produces an immense earthquake every 200 to 500 years. The most recent one was in 1700. Just how big is the Big One? The Richter scale, which measures ...

While the 1700 earthquake is the most studied, scientists have found evidence of eight to 10 other Cascadia quakes. These ...

Washington state emergency management officials posted on social media that while it can be scary to see a 6.0 magnitude quake happening near the Cascadia Subduction Zone, the one Wednesday was in ...

Portland is in the Cascadia Subduction Zone which hasn't produced an earthquake since 1700, but scientists say there's a 37% chance a major earthquake could rock the region within the next 50 years.