Mariana Trench

Mariana Trench, world’s deepest ocean trench, located in the North Pacific Ocean. It is an arc-shaped valley extending generally north-east to south-west for 2,550 km (1,580 mi); its average width is 70 km (40 mi), and it reaches a maximum depth of 11,033 m (36,198 ft). The trench is the meeting place of two oceanic crustal plates. The older and denser Pacific Plate to the east is subducting beneath the younger and less dense Philippine Plate to the west at a rate of more than 10 cm (4 in) per year. The volcanic Mariana Islands were formed along the western margin of the trench as the result of this subduction activity.

Near the south-western extremity of the trench, 340 km (210 mi) south-west of the island of Guam, is the deepest point on earth. This point, the Challenger Deep, is estimated to be 11,033 m (36,198 ft) deep. It was named after HMS Challenger II, the vessel of those who discovered the point in 1948. In 1960 Jacques Piccard and a group of scientists in the bathyscaphe Trieste entered the Challenger deep to make the deepest yet descent of the Mariana Trench, to 10,924 m (35,840 ft).