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.
A new study published in the current issue of Geoarchaeology claims that earthquake-prone areas along the edges of tectonic plates were far more likely to give birth to great ancient civilizations than less dynamic landscapes. The author of the paper, Eric Force, a (U of A Wildcat!) says that 13 of 15 ancient civilizations sites aren’t the product of chance. Instead, ancient people appear to have chosen to settle close to a tectonic plate boundary. The exceptions were in ancient China and Egypt. [Image Adapted from Eric R. Force, Geoarchaeology: An International Journal, 23 (2008)]