The deepest point in the world's oceans is the Challenger Deep, located in the Mariana Trench in the Western region of the Pacific Ocean. In this region, the ocean reaches its deepest point at The Challenger Deep. This region got its name from the British Survey Ship Challenger II, which discovered this location in 1951. The Mariana Trench, which lies to the east of the Mariana Islands, measures approximately 2,500 km (1553 miles) long and about 70 km (43 miles) across. Although many measurements of the Challenger Deep have been made in the past, the most accurate measurement was made by Japanese probe in 1995, resulting in a depth of 10.911 km (6.831 miles) below sea level.
Mariana's Trench formation
The Mariana Trench is situated in an area where two tectonic plates converge with one another, forming a subduction zone, where the western edge of the Pacific plate subducts underneath the edge of the Mariana plate. At the point where these two plates collide with one another, is where one of the plates submerges into the mantle, forming a feature called an ocean trench. Plate tectonics is also responsible for the creation of the Mariana Islands. The nature of its formation and the fact that the largest tectonic plate on Earth submerges under another tectonic plate makes the Mariana Trench the deepest ocean region on Earth.
The Challenger Deep
In 1951, the Challenger Deep surveyed the Mariana Trench during which the deepest point on the ocean was discovered at about 11,000 meters (11 km or 6 miles) deep. There have been various attempts to measure the challenger Deep; however, the closest measurements describe the Challenger Deep at a little less or a little more than 11,000 meters (6 miles) below the ocean's surface. It is been estimated that if Mount Everest, the tallest mountain on Earth, at 29,035 feet, was to be compared to the Challenger Deep, it would still need one mile up from its summit to reach the surface of the ocean.
There have been four recorded descents to the Marian Trench. The first attempt was made in January 23, 1960 by Don Walsh and Jacques Piccard in the bathyscaphe Trieste, during which they reached a depth of 10,916 meters (35,814 ft.). KAIKO, a remotely operated vehicle reached the deepest point at the Mariana Trench on March 24, 1995. Nereus, a remotely operated vehicle, reached the bottom of the Challenger Deep, at a depth of 10,902 meters (6 miles), on May 31, 2009. The most recent submergence to the Mariana Trench was made by film director James Cameron on March 26, 2012 in a submersible called The Deepsea Challenger during which he reached 10,898 meters (35,756 ft.) of depth.
Life found in the Challenger Deep
Despite the cold temperatures, ranging from 1 to 4 °C (34-39 ° F), and a pressure of more than 1,000 times that of the atmospheric pressure at sea level, life seems to exist at these depths. During the first manned expedition in 1960, scientists observed large marine creatures, such as crustaceans, invertebrates and fish. In subsequent expeditions, samples were collected containing tiny organisms. The decaying remains of marine animals are deposited in the ocean sea floor, forming biogenous ooze. Recent expeditions using dropcams have detected single-celled amoebas (xenophyophores) of 4 inches (10 cm) in size.
Hydrothermal vents, also called black smokers, are very common in the Mariana Trench. These vents emit sulfur compounds and other minerals. The water from hydrothermal vents, which is rich in dissolved minerals, supports huge amounts of chemoautotropic bacteria. These bacteria use sulfur compounds to produce organic material for food, creating complex food webs in which the smaller marine animals serve as food sources for bigger animals. The biodiversity thriving in this environment relies on hydrothermal vents as a source of energy.
Hawaiian scientists of the Hawaiian Institute of Geophysics and Planetology discovered a region on the Mariana Trench with a similar or even possibly larger depth than that of the Challenger Deep. During a survey in the region of Guam in the Pacific, they detected the deep spot with a sonar mapping system attached in the rear end of the research vessel. They named the new deep spot the HMRG Deep, which stands for Hawaii Mapping Research Group, after the research team of scientists who discovered the spot.