Final answer:
The Mariana Trench, with depths approaching 11,000 m, is located in the western Pacific Ocean and is part of the aphotic and benthic zones of the ocean.
Step-by-step explanation:
The Mariana Trench, known to contain the deepest parts of the world's oceans, is located in the western Pacific Ocean. The trench, including the Challenger Deep, extends approximately 11,000 m (about 6.8 mi) deep, far surpassing the average ocean depth of 4267 m or 14,000 ft. This region is a part of the benthic realm which covers the entirety of the ocean bottom - from shorelines to the deepest trenches. Furthermore, the trench lies within the aphotic zone, a zone where sunlight is unable to penetrate deep enough to allow for photosynthesis, usually at depths greater than 200 m (650 ft).