PORTLAND, Ore. -- A new study suggests some sections of the Oregon coast, and some areas inland, could shake much less than others during "The Big One."
The Cascadia Subduction Zone is a 600-mile long fault off the Oregon-Washington coast capable of producing a magnitude 9 earthquake.
"There's no question of the likelihood of it," said Oregon State University marine geologist Chris Goldfinger.
Goldfinger has been studying the fault for decades and recently found distinct differences in different sections of it. He found some sections are gradually creeping or slipping, releasing energy as they go. He calls those areas of the fault "unstuck."
"Lincoln City is right in the middle of the unstuck patch, so it could be that Lincoln City gets a bit of a break," he said.
But he also found other sections that are very "stuck." In other words, they haven't moved in a long time, so when they do finally break, they will break hard.
"It has the effect of being a bigger earthquake for places that are close to them."
Goldfinger says one stuck section stretches from Astoria down to Netarts Bay, and another from roughly Newport down to Florence. The section in between is the creeping section. People who live closer to that "unstuck" section may experience less severe shaking during the "Big One." And the tsunami generated may also be smaller.
But those closer to the stuck areas won't be so lucky, and that includes Portland.
"Portland is pretty much on the fully locked patch," said Goldfinger.
He hopes this research could be used to focus on seismically upgrading buildings in those areas - which will likely shake the hardest.
"The more data people have in their hands, hopefully the better decisions they can make," said Goldfinger.
Goldfinger says there's a roughly 30 percent chance of a mega quake striking our area in the next 50 years.