The Juan de Fuca plate has a half spreading rate of approximately 25 mm/yr to 35 mm/yr (Govers & Meijer, 2001). The Juan de Fuca Plate itself has since fractured into three pieces, and the name is applied to the entire plate in some references, but in others only to the central portion. For example the Juan de Fuca Plate is actually three separate plates (Gorda, Juan de Fuca, and Explorer) that all move in the same general direction but at slightly different rates. The two plates became a destructive plate boundary – when a continental plate meets an oceanic plate. The Juan de Fuca plate is created by seafloor spreading just offshore at the Juan de Fuca ridge.If the magma at a continental arc is felsic, it may be too viscous (thick) to rise through the crust. TECTONIC PLATES thinking about the future TECTONIC PLATES Mt St Helens is on the plate boundary between Juan de Fuca and the North American plates, the boundary is also a part of the Ring of Fire. The Juan de Fuca Ridge is a mid-ocean spreading center and divergent plate boundary located off the coast of the Pacific Northwest region of North America. The molten mantle rock produced by this subduction is responsible for the major volcanoes in the Cascade Range. The Gorda plate is separated from the Juan de Fuca plate by a transform boundary along the Blanco Fracture zone (see figure 2) and the Explorer plate is separated by the Sovanco transform zone (Stock & Lee, 1994). 5 Earthquakes in the Juan de Fuca Plate ... We also considered a third type of plate boundary where plates neither converge nor diverge but instead move past each other without destroying or creating lithosphere. The Juan de Fuca microplates are believed to be the last remaining fractured portions of the Farallon plate in the continental U. S. region. These large bodies of intrusive igneous rocks are called batholiths, which may someday be uplifted to form a mountain range. Boundaries. EARTHQUAKES, FAULTS, AND PLATES As part of the investigation, H.F. Reid proposed the elastic rebound theory of earthquakes, where materials at distance on opposite sides of the fault move smoothly relative to each other, but friction on the fault “locks” each side and … The Juan de Fuca Ridge is a mid-ocean spreading center and divergent plate boundary located off the coast of the Pacific Northwest region of North America. Seals and sea lions can also often be seen playing offshore. The Juan de Fuca Plate also spans 300 miles. The Juan de Fuca plate and the North American plate are currently smashing into each other, and Juan de Fuca plate is subducting (sinking below) because it is denser. The tectonic plate that runs 250 miles away from the coast of Washington, and Oregon. Today, the Juan de Fuca Ridge pushes the Juan de Fuca Plate underneath the North American plate, forming the Cascadia Subduction Zone.