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
South Sandwich Trench South Sandwich Trench The South Sandwich Trench is a deep arcuate trench in the South Atlantic Ocean lying 100 km to the east of the South Sandwich Islands. The trench is produced by the subduction of the southernmost portion of the South American Plate beneath the small South Sandwich Plate. The South Sandwich Islands constitute a volcanic island arc which results from this active subduction. Mount Belinda on Montagu Island is an active volcano. It is the deepest trench of the Southern Atlantic Ocean, and the second deepest of the Atlantic Ocean after the Puerto Rico Trench. The trench is