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.
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Geologic Hazard Photos
The National Geodetic Data Center (NGDC) of NOAA has an online collection of photos of various geologic hazards. Many of the photos are from older sets of 35mm slides that have been digitized. They are free to use provided you credit the photographer and the NGDC as the source. The would be really useful for educators and for powerpoint presentations. The only drawback is that they are in TIF format and some of them could use some retouching. (Photo by University of Colorado, made available by NOAA/NGDC)
Geologists Recover Pieces of San Andreas Fault from 2 Miles Deep
As a follow up to a previous post, the San Andreas Fault Observatory at Depth (SAFOD) team has announced that they have successfully completed their drilling and obtained cores of the San Andreas Fault at depths in excess of 2 miles below the surface. The zone of interest is approximately 135-ft in length. The core size is 4-in diameter. They have cemented in a 7-in casing and the next phase of the project will be to perforate the casing within the fault and install monitoring equipment consisting of seismometers, accelerometers, tiltmeters and a fluid pressure transducer. Read on for more info and links. (Image credit: EarthScope / NSF)