There is stronger compression on Eurasian plate at Nankai trough, while there is no compression at Ryukyu trench where an extension may exist, caused by the secondary mantle flow.

• 在南海海槽一带有较强的挤压，在琉球海沟一带由于两板块耦合较弱及冲绳海槽的开裂，没有形成对东亚大陆的挤压；