Philippine Sea Plate
The eastern side of the Okinawa Plate forms a convergent boundary with the Philippine Sea Plate, forming the Ryukyu Trench and the island arc that forms the Ryukyu Islands. The Okinawa Plate is bounded on the western side by the Okinawa Trough, a back arc basin and divergent boundary with the Yangtze Plate. A section of the southern boundary between the Okinawa Plate and the Philippine Sea Plate is a former subduction zone that now accommodates oblique slip and was the location of the 1771 Great Yaeyama Tsunami. The northern side of the Okinawa plate is bordered by the Amur Plate.