Cascadia GPS 2 “Locked and Loading” Lesson Plan

This classroom activity is an enhancement of the Cascadia GPS Gumdrop activity. It is intended for teachers who wish to provide their students with a more complete spatial picture of deformation of the Pacific Northwest continental margin. The big-picture is that coastal stations of Oregon and Washington are being pushed toward the northeast at about ½ the velocity of Juan de Fuca Plate motion with respect to interior North America. Urban corridor stations in the Puget Lowlands and Willamette Valley are being pushed toward the northeast at about ¼ of that velocity. Stations on the east sides of Oregon and Washington are not moving at all. The clear implication is that coastal areas are moving towards eastern areas as the active continental margin is compressed in SW – NE direction. Strain is building within the Pacific Northwest margin of the North American Plate as the Juan de Fuca Plate pushes the North American Plate margin toward the northeast. This accumulating strain will eventually be released in the next great earthquake on the Cascadia Subduction Zone. The plate boundary regions of the Juan de Fuca and North American plates are “locked and loading”.