What tectonic plate is located west of a trench which reaches a maximum-known depth of 10994 m?
Mariana Plate The Mariana Plate is a small tectonic plate located west of the Mariana Trench and forms the basement of the Mariana Islands. It is separated from the Philippine Sea Plate by a long divergent boundary with numerous transform fault offsets. The boundary between the Mariana and the Pacific Plate to the east is a subduction zone with the Pacific Plate subducting beneath the Mariana. The Mariana Trench forms the southeastern boundary and the Izu-Ogasawara Trench the northeastern boundary.
Cobb Seamount Cobb Seamount is a seamount (underwater volcano) and guyot located 500 km west of Gray's Harbor, Washington, United States. Cobb Seamount is one of the seamounts in the Cobb-Eickelberg Seamount chain, a chain of underwater volcanoes created by the Cobb hotspot that terminates near the coast of Alaska. It lies just west of the Cascadia subduction zone, and was discovered in 1950 by MV "John N. Cobb". By 1967, over 927 km of soundings and dozens of samples from the seamount had been collected.