While thousands of climbers have successfully scaled Mount Everest, the highest point on Earth, only two people have descended to the planet’s deepest point, the Challenger Deep in the Pacific Ocean’s Mariana Trench. Mr. Cameron plunged about 11 kilometres down the Mariana Trench in the western Pacific, the first one-person mission to the lowest point of the oceans.
“I felt like I — in the space of one day — had gone to another planet and come back,” he said, saying the ocean floor was a “completely featureless, alien world.” The Mariana Trench or Marianas Trench is the deepest known part of the world's oceans.
It is located in the western Pacific Ocean, to the east of the Mariana Islands. The trench is about 2,550 kilometres (1,580 mi) long with an average width of 69 kilometres (43 mi).
Now, researchers have released audio of a strange booming sound heard in the deepest part of the ocean, lasting between 2.5 and 3.5 seconds, the five-part call includes deep moans at frequencies as low as 38 hertz and a metallic finale that pushes as high as 8,000 hertz.