Just off the coast of northern California near Cape Mendocino and the towns of Eureka and Petrolia, the Mendocino triple junction is the point where three tectonic plates meet: the North American Plate, the Gorda Plate, and the Pacific Plate. The point is thus the intersection of three faults: the San Andreas Fault, the Mendocino Fault, and the Cascadia Subduction Zone. The complicated interactions at the site make it particularly seismically active.