Tethyan Trench Tethyan Trench The Tethyan Trench was an ancient oceanic trench that existed in the northern part of the Tethys Ocean during the middle Mesozoic to early Cenozoic eras. The Tethyan Trench formed when the Cimmerian Plate was subducting under eastern Laurasia, around 200 million years ago, in the Early Jurassic. The Tethyan Trench extended at its greatest during Late Cretaceous to Paleocene, from what is now Greece to the Western Pacific Ocean. Subduction at the Tethyan Trench probably caused the continents Africa and India to move towards Eurasia, which resulted in the opening of the Indian Ocean. When the Arabian
Mariana Trench Mariana Trench The Mariana Trench or Marianas Trench is located in the western Pacific Ocean approximately east of the Mariana Islands, and has the deepest natural point in the world. It is a crescent-shaped trough in the Earth's crust averaging about long and wide. The maximum known depth is (± ) at the southern end of a small slot-shaped valley in its floor known as the Challenger Deep. However, some unrepeated measurements place the deepest portion at . For comparison: if Mount Everest were dropped into the trench at this point, its peak would still be over under water. At