Cascadia subduction zone 
Juan de Fuca Plate (Wikipedia) The Juan de Fuca Plate is a small tectonic plate (microplate) generated from the Juan de Fuca Ridge that is subducting beneath the northerly portion of the western side of the North American Plate at the Cascadia subduction zone. It is named after the explorer of the same name. One of the smallest of Earth’s tectonic plates, the Juan de Fuca Plate is a remnant part of the once-vast Farallon Plate, which is now largely subducted underneath the North American Plate. The Juan de Fuca Plate system has its origins with Panthalassa’s oceanic basin and crust. The remains of the Farallon Plate are the Explorer, Gorda, and Juan de Fuca plates, subducting under the northern part of the North American Plate; the Cocos Plate subducting under Central America; and the Nazca Plate subducting under the South American Plate.
