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.