The deepest place on Earth is located in the southwestern Pacific Ocean – Marian Trench. It is located near the Mariana Archipelago, west of the Philippines. These islands are named after a missionary who wanted to commemorate the Queen of Spain, Maria Anna of Austria.
The Mariana Trench on the map is located almost halfway between Papua New Guinea and Japan – this is where subduction occurs, that is, one tectonic plate “lies” under another. The largest tectonic plate, the Pacific Plate, is part of the Philippine Plate. It is thanks to this that the Mariana Trench was formed.
Depth of the Mariana Trench
This deepest spot is called the Challenger Deep after the research ship. This is the place we often mean when we say the Mariana Trench. The Challenger Deep consists of three valleys, 6 to 10 km long and 2 km wide. The depth of the western and eastern valleys was determined by sonar and amounted to more than 10,920 meters. However, the depth of bedrock is still unknown. According to the records of the probes that penetrated the Mariana Trench, the bottom is covered with a layer of stones and dust.
Is there life in the Mariana Trench?
Most marine animals on our planet live in shallow coastal areas where there is light, oxygen, food and low salinity. The deeper, the less light and therefore fewer photosynthetic plants. Already at 1000 m below sea level, the ocean becomes completely dark, and the only source of light here is bioluminescence. Many creatures living in the dark depths feed on the so-called “sea snow” – debris falling from higher zones, including carrion.
4000 meters below sea level is the so-called abisal, the zone of the “bottom of the ocean”. This is where the Mariana Trench really begins. Interesting facts about life in the depths are amazing: for many years it was believed that the ocean floor was a desert for life, but about 80% of the species that inhabit this area have not yet been explored by people. Life often gathers around hydrothermal vents, which heat water with energy from the Earth’s interior.
The pressure at the bottom of the Mariana Trench is very high – 1086 bar, which means that it is more than a thousand times higher than at sea level. Probably, vertebrates can only withstand depths up to 8000 m below sea level, but snails and trepangs do live in the Mariana Trench.
Instead of plants, the first link in the food chain of this zone is chemosynthetic bacteria that process hydrogen, methane and hydrogen sulfide. Many Other Creatures Feed on Marine Snow Although the location of the Mariana Trench is well known and probes have reached the bottom, the fauna of this zone is still very little known.
Research history
As stated above, the depth is named after the British ship HMS Challenger (meaning “challenger”). The Challenger expedition in the 1870s laid the foundations for modern oceanography. The ship circled the Earth, covering more than 130,000 km, finding more than 4,000 unknown species along the way.
It was the researchers from this ship who on March 23, 1875 discovered a huge basin near the island of Guam and were the first to find out how many meters the Mariana Trench was. Using a cable probe, the depth was estimated at 4,475 fathoms or 8,184 meters. More recent studies have shown a more accurate depth value.
After World War II, the British ship Challenger II repeated the feat of its predecessor in 1951, this time using a more accurate and less labor-intensive sonar method. It was then that the exact location of the Challenger Abyss was determined – the depth was almost 11 km, 10900 meters.
Research probes have only recently been dropped into the Abyss The Japanese probe Kaiko has collected samples from the seafloor several times, as has its successor, the ABISMO underwater drone. Only a few people have visited the Mariana Trench itself so far. The first to fall to the bottom were the Swiss engineer Jacques Picard and the American Don Walsh aboard Picard’s Trieste bathysphere.
At present, perhaps the most famous explorer of the Challenger Abyss is Canadian director James Cameron, creator of such hits as The Abyss, Titanic, Avatar and The Terminator. All these films show that Cameron loves the sea and nature. The Mariana Trench is one of the director’s obsessions. In 2012, he became the first person to descend alone to the bottom of the Mariana Trench.
Only in recent years has it become possible to regularly dive into the Abyss. One of the pilots of the DSV Limiting Factor submarine is retired US Navy Commander Victor Vescovo, the first person to visit the Mariana Trench twice. Among his many discoveries, perhaps the saddest is that he noticed plastic bags at the bottom.
This depth continues to fuel the human imagination. With uncharted places like the Mariana Trench, the world map still contains mysterious blank spots. Unfortunately, even this place has not escaped the terrible anthropogenic impact on the environment.
