Preliminary results from a study related to the subduction of the Juan De Fuca Plate beneath the North American Plate off the coast of Washington and British Columbia indicate that the potential mega-thrust earthquake could strike closer to the Seattle-Tacoma area than previously thought. I believe this project is the same one where I posted their press release about two years ago. According to the article, the average return period for these mega-thrust earthquakes is 400 to 500 years with a range between 300 and 800 and the estimated magnitude of around 9.0. The last mega-thrust earthquake along the Cascadia Subduction Zone was in January of 1700. Previously, scientists predicted the earthquake would be centered just off the coast, they now think it could be 30 miles or more inland, under the Olympic Peninsula to the west of the Seattle-Tacoma area. Source: Physorg.com via Geology.com.
Thanks to approximately $100 million from President Bush’s proposed 2009 budget, the $1.8 billion project creating a light-rail line from downtown Seattle to the University of Washington is likely to break ground some time this year. The project will involve twin bored tunnels on the order of 3 miles in length. It is scheduled to open for use in 2016.
There is another notable tunnel project associated with the Seattle Light Rail, known as the Beacon Hill tunnel which I have blogged about before.