To the north lies the Cascadia subduction zone, where a section of the Juan de Fuca Plate called the Gorda Plate is being subducted under the North American Plate, forming a trench (T). Another transform fault, the Mendocino Fault (F), runs along the boundary between the Pacific Plate and the Gorda Plate. Where the three intersect is the seismically active, F-F-T Mendocino Triple Junction. The Amurian Plate, the Okhotsk Plate, and the Philippine Sea Plate meet in Japan near Mount Fuji. (see Mount Fuji's Geology) The Azores Triple Junction is a geologic triple junction where the boundaries of three tectonic plates intersect: the North American Plate, the Eurasian Plate and the African Plate, R-R-R. The Boso Triple Junction offshore Japan is a T-T-T triple junction between the Okhotsk Plate, Pacific Plate and Philippine Sea Plate. The North Sea is located at the extinct triple junction of three former continental plates of the Palaeozoic era: Avalonia, Laurentia and Baltica. The South Greenland Triple Junction was an R-R-R triple junction where the Eurasian, Greenland and North American plates diverged during the Paleogene. The Chile Triple Junction is where the South American Plate, the Nazca Plate, and the Antarctic Plate meet. See also References Oreskes, Naomi, ed., 2003, Plate Tectonics: an Insider's History of the Modern Theory of the Earth, Westview Press, Plate tectonics