The expected 2011 episodic tremor and slip (ETS) event has done the unexpected by starting months early. These events happen in the deep part of the Cascadia Subduction Zone, “down dip” from the area where the Juan de Fuca Plate is completely locked against the North American Plate. These “slow earthquakes” reoccur every 14 months on average and have been remarkably consistent over the past decade. Another of these events was expected to begin in late October, early November 2011 but has begun months early. Details from the Pacific Northwest Seismic Network.
Cannon Beach has been proactive on preparing for earthquakes, with a vital emergency preparations committee, leadership and citizens. Cannon Beach recently completed 2 important studies, one on geotechnical conditions which confirmed weak soils at the existing city hall location, and another on tsunami evacuation simulation. Please see more details from The Oregonian here.