What are the chances of an earthquake in Seattle happening in the next decade?

the answer is 3

According to our fathead mayor, the chances are 100% and the sooner the better!

@drClaw: you are seriously misinformed. The true answer is 4 to 8.

The answer is that our methods are not advanced enough to know. That area is due, but it cannot be narrowed to a 10-year window. Here is and except from a 2007 scientific paper. (Emphasis mine)

“To date, non-volcanic tremor and LFEs have been found primarily in subduction zones—seismically active faults where two tectonic plates meet and one plate constantly dives beneath the other. The most destructive earthquakes ever recorded have occurred in subduction zones, in places such as Chile, Japan, Alaska, Washington state and British Columbia. A recent example was the devastating 2004 earthquake near Sumatra, where a magnitude 9.2 temblor triggered powerful tsunamis that killed more than 200,000 people.

These violent mega-thrusts occur every 100 to 600 years, depending on the location. Recent studies suggest that giant quakes, which form at relatively shallow depths, are preceded by a series of much deeper events called slow (or silent) earthquakes, which displace the ground without shaking it. A slow earthquake can last days, months or years without being felt at the surface.

“In early February, Cascadia experienced one of those slow events, and the Canadian Geological Survey issued a public warning based on increased tremor activity,” Shelly noted. “The survey announced that there was a greater likelihood of a major earthquake in the next two or three weeks based on the activity of the tremor. Fortunately, the earthquake didn’t happen, but the real utility of the warning was to get people thinking about earthquake hazard in that region. It shows that tremor is starting to be used for earthquake forecasting.”

The study, “Non-Volcanic Tremor and Low-Frequency Earthquake Swarms,” by D. Shelly et al., appears in the March 15 issue of Nature.

Source: Stanford University