The last megathrust earthquake at the Cascadia subduction zone was the 1700 Cascadia earthquake, estimated to have a moment magnitude of 8.7 to 9.2.

citation

Wikipedia contributors. (2023, September 26). Juan de Fuca Plate. In Wikipedia, The Free Encyclopedia. Retrieved November 1, 2023, from https://en.wikipedia.org/w/index.php?title=Juan_de_Fuca_Plate&oldid=1177150467

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.