Okinawa ocean trough and Ryukyuislandarc were formed in late Miocene.
中新世晚期，冲绳海槽和疏球岛弧形成。
2
The east slope is slow, and is the inserting side from the northwest Philippine Plate into the RyukyuIslandArc, connecting with the ocean basin.
东坡（洋坡）缓，是西北菲律宾海板块向琉球岛弧下插的一边，与大洋盆地相连。
3
According to all of the results, we can concluded that, 1 the seismic sequences developed in the west shelf, trough basin and RyukyuIslandarc are different.