The deepest oceanic trench 'Mariana' is located in -

Pacific Ocean

The deepest oceanic trench, the Mariana Trench, is located in the Pacific Ocean.

The Mariana Trench is the deepest part of the world's oceans and is situated in the western Pacific Ocean. It reaches its maximum known depth at a point known as the Challenger Deep. The Mariana Trench is a fascinating and extreme environment that provides valuable insights into the geology and biology of the deep ocean. It remains a significant area of scientific interest and exploration.