Water covers around 75 percent of the earth’s surface. The biggest chunks are the deep oceans which its majority are not yet explored, reach or measured by our today’s technologies.
The deepest known is the Mariana Trench. It is located in the western Pacific east of the Philippines, approximately 124 miles (200 kilometers) east of the Mariana Islands. The Mariana Trench is a crescent-shaped scar in the Earth’s crust that measures more than 1,500 miles (2,550 kilometers) long and 43 miles (69 kilometers) wide on average.
The first depth measurement in the Mariana Trench was made by the British survey ship HMS Challenger in 1875. They used ropes and lead weights to plumb the ocean’s depth. The greatest depth recorded at that time was 8,184 m.
In 1899 a USS Nero, Challenger II surveyed Mariana Trench with more sophisticated technology – the echo sounding technology which they recorded a 9,636m depth. This was followed by several discovery missions in 1957 the Soviet vessel Vityaz reported a depth of 11,034m, while a depth of 10,924 m is recorded by the Japanese survey vessel Takuyō with their technology narrow-multi-beam echo sounder in In 1984.
In 2012, the National Geographic together with its scientific discovery team launched the Deepsea Challenge mission aimed to advance the world’s understanding of the Mariana Trench vast biological and geological phenomena. The historic expedition was the first extensive scientific exploration in a manned submersible piloted by James Cameron who successfully landed and collected geological and marine samples at the Mariana Trench deepest depth of 10,999m below the ocean surface.
The Marian Trench discovery and other deep-sea discoveries combined only explored 5 percent of the vast ocean depth.