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.
Project Related
Rising Costs and Delays in Seattle Area Wastewater Plant and Tunnels
In keeping with our theme of rising costs on tunnel projects, the Brightwater sewage-treatment plant and treated waste pipeline project in King County Washington (Seattle area) is now up to at least $1.84 billion according to the lead consultant on the project. The treated waste pipeline is 13 to 14-miles long and at depths of 40 to 440-ft! It is being constructed nearly entirely by TBM. One source of delay was due to a tunneling subcontractor not being able to get parts (ball bearings?) because they were all being requisitioned by the US War Department for use in military equipment in Iraq and Afghanistan. Click through for information sources and links.
Geologic Hazards
Regulators aware for years of understated seismic risks to nuclear plants
With the events in Japan on everyone’s mind, it’s of course to be expected that seismic safety at nuclear power plants in the U.S. becomes a hot topic. This article discusses how the Nuclear Regulatory […]
Project Related
$1 Million More for Geotechnical Work on Seattle Light-Rail Tunnel
The Seattle Post-Intelligencer reports that Seattle’s "Sound Transit" board members have approved an additional $1 Million in funds for "unanticipated" geotechnical engineering related to the Beacon Hill light-rail tunnel. The project geotechnical firm is Shannon […]