Diamantina Deep Diamantina Deep The Diamantina Deep is located in the Diamantina Trench southwest of Perth, Western Australia. The Diamantina Trench is in the eastern part of the larger Diamantina Fracture Zone, which stretches from the Ninety East Ridge to the Naturaliste Plateau, off the lower part of Southwest Australia. It is one of the deepest points (surpassed by the Sunda Trench) in the Indian Ocean at . It is located about west-southwest of Perth at . A survey in 1961 by the Australian oceanographic survey ship confirmed the bathymetry and conducted a scientific survey. The trench (and the Fracture Zone) was
Ryukyu Trench gentle, reaching only 40-50° at 70 km depth. Ocean bottom seismography studies of the Ryukyu trench provide insight into the P-wave velocity structure of the area. In the northern part of the trench, several transects have been studied, including a profile of the back arc region parallel to the trench, a transect spanning the trench, fore arc and back arc region, and a transect spanning the Ryukyu volcanic arc. The transect perpendicular to the length of the trench images many distinct velocity layers. The sedimentary wedge created by subduction has four distinct layers with p-wave velocities of 1.8 km/s, 2.8-2.9