has anyone been to the bottom of challenger deep
Challenger Deep On 26 March 2012 (local time), Canadian film director James Cameron made a solo manned descent in the DSV Deepsea Challenger to the bottom of the Challenger Deep.[9][10][11][26] At approximately 05:15 ChST on 26 March (19:15 UTC on 25 March), the descent began.[27] At 07:52 ChST (21:52 UTC), Deepsea Challenger arrived at the bottom. The descent lasted 2 hours and 36 minutes and the recorded depth was 10,898.4 metres (35,756 ft) when Deepsea Challenger touched down.[28] Cameron had planned to spend about six hours near the ocean floor exploring but decided to start the ascent to the surface after only 2 hours and 34 minutes.[29] The time on the bottom was shortened because a hydraulic fluid leak in the lines controlling the manipulator arm obscured the visibility out the only viewing port. It also caused the loss of the submersible's starboard thrusters.[30] At around 12:00 ChST (02:00 UTC on 26 March), the Deepsea Challenger website says the sub resurfaced after a 90-minute ascent,[31] although Paul Allen's tweets indicate the ascent took only about 67 minutes.[32] During a post-dive press conference Cameron said: "I landed on a very soft, almost gelatinous flat plain. Once I got my bearings, I drove across it for quite a distance ... and finally worked my way up the slope." The whole time, Cameron said, he didn't see any fish, or any living creatures more than an inch (2.54 cm) long: "The only free swimmers I saw were small amphipods"—shrimplike bottom-feeders.[33]
Mariana Trench The Mariana Trench or Marianas Trench[1] is the deepest part of the world's oceans. It is located in the western Pacific Ocean, an average of 200 kilometres (124 mi) to the east of the Mariana Islands, in the Western Pacific east of Philippines. It is a crescent-shaped scar in the Earth's crust, and measures about 2,550 km (1,580 mi) long and 69 km (43 mi) wide on average. It reaches a maximum-known depth of 10,994 metres (36,070 ft) (± 40 metres [130 ft]) at a small slot-shaped valley in its floor known as the Challenger Deep, at its southern end,[2] although some unrepeated measurements place the deepest portion at 11,034 metres (36,201 ft).[3] For comparison: if Mount Everest were dropped into the trench at this point, its peak would still be over 2 kilometres (1.2 mi) underwater.[a] In 2009, the Marianas Trench was established as a United States National Monument.[5]