Bathymetry and possible tectonic interaction of the Uyeda Ridge with its environment

Abstract

The Uyeda Ridge and the features surrounding it are discussed from the bathymetry provided by a total coverage multi-beam array sonar survey. Heffner's Fault is speculated on as having been the result of a leaky transform between two ancient NW Pacific Ocean plates. That boundary is still shown as a ridge-fault-ridge boundary consisting of the Ryofu-Kashima Ridge, Heffner's Fault, and the Uyeda-Round Ridge. Intraplate seismicity shows Heffner's Fault to be still active (Fig. 1). Presently, an across-trench manifestation of subduction processes of the Uyeda Ridge is observed through the interaction of the Uyeda Ridge and adjacent submarine canyons. These canyons may have originated as stress faults produced by a subducting feature such as the Uyeda Ridge. The provenance of these canyons is discussed with reference to their tectonic implications.