It is the Mariana Trench, a depression 2,550 km long and about 11 km deep, located between Japan and Australia. Close to it, giant landforms, such as Mount Everest (8.8 km high) and the Grand Canyon (446 km long), become small. The trench is formed by the collision between the Pacific and Philippine tectonic plates. Despite moving in the same direction, the Pacific plate is faster and runs over the Philippine plate. The deepest point is the Challenger Depression, discovered in 1960. At the time, Don Walsh, from the USA, and Jacques Piccard, from Switzerland, used a submersible to reach a depth of 10.9 km. In subsequent years, only unmanned missions explored the trench. The mini-submarine Nereus descended the most: 10,902 m below sea level in 2009.
DEEP IMPACT
James Cameron wanted to look for references for the sequel to Avatar in the Challenger depression. The idea did not work because there is a risk of tremors in the region since the Japanese tsunami of 2011.
SOURCES: BBC, The New York Times, hypertextbook.com, Faculty of Marine and Environmental Sciences of the University of Algarve and the US National Oceanic and Atmospheric Administration (NOAA).