A team of scientists said last week that a fault under Seattle triggered a large earthquake a millenium ago and possibly could pose a threat again.
Articles published Friday in the journal Science say the fault produced a large earthquake about 1,000 to 1,200 years ago. By today's measurements the quake probably registered about 7.0 on the Richter scale, the scientists said.
Although Seattle may be at greater risk than anticipated, the scientists stressed that they need more information about the history and stresses on the fault to assess accurately the potential danger to the region.
The fracture under Seattle, referred to informally by some as the Kingdome fault because it runs under the domed stadium, provides further proof of the earthquake possibilities in the Pacific Northwest. Large quakes have rattled Washington this century but have not struck heavily urbanized areas directly.
Seattle recently started work on serious earthquake planning. But many existing structures, including schools, were not built with seismic protection in mind.