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The mysterious and terrifying Mariana Trench

author:AI answers 100,000 whys

The Mariana Trench (Marianas Trench), also known as the Mariana Trench, is the deepest trench on Earth, located on the eastern side of the Mariana Islands in the western Pacific Ocean, even if you put Mount Everest upside down. Let's take a look at some details about the Mariana Trench:

The mysterious and terrifying Mariana Trench

Location: The Mariana Trench is located between 11°21' N and 21°30' N and 142°12' E and 166°48' E. That is, the bottom of the Pacific Ocean near the Mariana Islands in the northeast of the Philippines, from Iwo Jima in the north to near Yap Island in the southwest. It has trenches such as Aleutian, Kuril Islands, and Ogasawara in the north, and New Britain and New Hebrides in the south. It runs north-south and is about 2,550 km long and 70 km wide. The deepest part of the Mariana Trench is 6~11 kilometers, which is the deepest known part of the ocean, where the water pressure is high, completely dark, the temperature is low, the oxygen content is low, and the food resources are scarce, so it has become one of the most environmentally harsh areas on the earth. The deepest part of the Mariana Trench is the Challenger Deep, which reaches a depth of 10,994 meters, the deepest known point on Earth. In 1957, the Soviet research ship Vityaz echoed a depth of 11,034 meters (36,201 feet), naming the site "Mariana Deep Depression"; However, this data is never measured again and is therefore not used as a standard value.

The mysterious and terrifying Mariana Trench

Causes: The formation of the Mariana Trench is mainly due to the westward movement of the Pacific Plate and the subduction of the Mariana Plate to the west. This plate movement caused the crust of the seafloor to bend downward, forming deep trenches. The Mariana Trench is a plate subduction zone with active seabed geological movements, and the material composition and genesis of seamount volcanic rocks are of interest to marine geologists.

The mysterious and terrifying Mariana Trench

Biodiversity: Despite the extreme environment of the Mariana Trench, the pressure is intense and the light is impenetrable, many organisms live here. Amazingly, at such a deep seabed, scientists saw a flounder and a small red shrimp swimming. In addition, there are many microorganisms, bioluminescent zooplankton, etc., which have strong adaptability and have become important objects of deep-sea ecological research.

The mysterious and terrifying Mariana Trench

Scientific Adventures: Due to its extreme environment, the Mariana Trench has always been challenging for humans. The huge water pressure of up to 1100 atmospheres at the bottom of the trench is a huge challenge for mankind. The deep sea is a high-pressure, dark and icy world, usually only 2°C (very few seafloor temperatures can be as high as 380°C under the influence of geothermal heat). Many mountaineers have successfully conquered Mount Everest, but it is extremely difficult to explore the deep sea, and few people have successfully dived to the bottom of the trench. The first manned dive into the Challenger Abyss took place in January 1960, when scientists successfully descended to the bottom of the Mariana Trench for the first time aboard the U.S. Navy's Trieste deep-sea submersible. In March 2012, film director James Cameron single-handedly successfully dived into the Challenger Abyss, setting a new record for manned diving.

From June 22 to August 12, 2016, the mainland research ship "Discovery-1" carried out the first comprehensive 10,000-meter abyss research activity in the history of the development of mainland marine science and technology in the Mariana Trench. The "Haidou" unmanned submersible independently developed by the mainland dived 10,767 meters. This "Haidou" not only set a record for the maximum diving depth of a mainland underwater robot, but also obtained the temperature and salt depth data of the abyss below 10,000 meters and the entire sea depth profile for the mainland. This is another milestone in mainland marine science and technology after the successful 7,000-meter sea trial of the "Jiaolong", marking the beginning of the mainland's deep diving scientific expedition into the 10,000-meter era. Since then, the 10,000-meter deep sea is no longer a forbidden area for the mainland marine science and technology community!

In 2017, the Institute of Deep Sea Science and Engineering, Chinese Academy of Sciences, realized the long-term continuous observation of the 10,000-meter anchor submersible of the Mariana Trench for the first time, and obtained the world's first 10,000-meter seabed artificial seismic profile.

On May 27, 2019, China's ocean-going research vessel Science officially began to investigate a series of seamounts on the south side of the Mariana Trench in the western Pacific, and the ship's remote-controlled unmanned vehicle "Discovery" collected rare deep-water sea hares.

At 8:12 on November 10, 2020, the "Striver" successfully sat on the bottom in the Mariana Trench at a depth of 10,909 meters, setting a new record for manned deep diving in China.

Environmental protection: In recent years, the Mariana Trench has been under environmental pressure due to human activities such as overfishing and seabed mining. The United Nations and many other countries have begun to pay attention to this issue and have taken a degree of protection measures to ensure that this mysterious deep-sea area is properly protected. The results showed that the content of microplastics in the bottom seawater of the Mariana Trench 2673-10908m was 2.06-13.51 pcs/L, which was several times higher than that in the open ocean surface and subsurface water. In the surface sediment of the Mariana Trench 5108-10908m, the microplastic content is 200-2200 pcs/L, which is also significantly higher than the content in most deep-sea sediments.

In January 2011, an international team of scientists discovered that the Mariana Trench stored a lot of carbon, which means that the trench plays a more important role in regulating the Earth's environment than previously realized. The Mariana Trench acts like a sediment collector, with more carbon converted by bacteria in the trench than on the seafloor plain at a depth of 6,000 meters. This suggests that the carbon content in the trench is higher than previously thought by researchers, who did not realize that there was such a carbon dioxide collection tank in the deep sea. The scientists' next idea is to quantify the results to figure out exactly how much more carbon is in deep-ocean trenches than in other seas, and how much carbon bacteria convert into water, which could help researchers better understand the role of deep-sea trenches in regulating climate.

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