Ryukyu Trench

A competing hypothesis claims that no transform fault motion is involved in the displacement, but rather the trench is continuous up to the northeast continental margin of Taiwan.

A third hypothesis maintains that the trench is continuous through the continental margin right up to the northeastern Taiwan coastline, also without the existence of a dextral north–south trending fault.

[6] Ocean bottom seismography methods combined with earthquake studies of the Wadati–Benioff zone constrain the dip angle of the Philippine Sea plate along the Ryukyu trench.

[7] Ocean bottom seismography studies of the Ryukyu trench provide insight into the P wave velocity structure of the area.

Separate ocean bottom seismography and multi-channel seismic studies provide insight into the structure of the northern end of the Ryukyu trench region.

[3] It has been hypothesized that the above structural heterogeneity, in particular the subducting paleo-arc crust and its associated bathymetric highs, is one reason why earthquakes in this region are not larger i.e. exceeding Mw  8.0.

Red line indicates the bathymetric low of the Ryukyu Trench
Undersea geographic features of the western Pacific