We explain what the Mariana Trench is, where it is located and how it was formed. In addition, we tell you what underwater life is like there.
What is the Mariana Trench?
The Mariana Trench is a depression in the ocean floor, that is, an oceanic trench or marine trench, considered the deepest area of the known oceans Located in the Pacific Ocean and shaped like a crescent, it is a sinkhole about 2,550 km long and 69 km wide. whose deepest known point is around 11 km below the sea surface.
This pit gets its name from its proximity to the Mariana Islands an archipelago formed by the summits of different underwater volcanic mountains and located about 200 km west of the trench, whose name comes, in turn, from that of Mariana of Austria (1634-696), wife of King Philip IV of Spain.
On the other hand, at the southern end of the trench there is a small ocean valley known as the Challenger Deep, whose name comes from the ship that discovered this oceanic trench between 1872 and 1876: the British corvette HMS Challenger.
As occurs in other ocean trenches, deep in the Mariana Trench, sunlight is scarce, so the waters darken and become icy, registering temperatures between 1 and 4 °C. Furthermore, the weight of the water column at such depths generates a pressure equivalent to more than a thousand times that of the atmosphere at the sea surface. Life in these complex regions has adapted to the surrounding conditions and, therefore, is substantially different from that which lives in the surface regions of the oceans.
See also: Ocean relief
Location of the Mariana Trench
The Mariana Trench It is located 200 km east of the Mariana Islands, in the Pacific Ocean in the vicinity of Guam and some distance from the coasts of Japan, Taiwan, the Philippines and Papua New Guinea.
Shaped like a crescent, the trench extends for 2,550 kilometers and submerges up to 11 kilometers below the sea surface: a depth so great that the highest mountain on the planet, Mount Everest, could be submerged in it (8849 m) of the Himalayan mountain range, and its summit would be almost two kilometers below the surface.
Formation of the Mariana Trench
The formation of the Mariana Trench was due, as is the case with most oceanic trenches, to meeting of two tectonic plates: in this case, the Pacific plate and the Marianas plate. This collision caused the first to subduct below the second, that is, to go deeper into the depths of the planet, which generated a significant sinking of the sea floor.
The regions near most oceanic trenches have significant seismic activity, as they are unstable regions where earthquakes and underwater volcanoes usually occur.
Life in the Mariana Trench
Contrary to what one might think, life in the depths of the Mariana Deep is not a rarity. Naturally, as the conditions of temperature, pressure and luminosity are so extreme, life differs significantly from what can be found on the surface. So, for example, Plant life is non-existent, since it is impossible to carry out photosynthesis
Instead, fauna includes a group of blind or bioluminescent animals (that is, capable of generating light with certain parts of the body), characterized by very slow metabolisms and bodies designed to swim with minimal effort. In such a hostile environment, animals tend to be solitary. For its part, predation and the rain of nutrients in the form of waste, which fall from the upper regions of the ocean, are the only source of food.
Most animal species in the Mariana Trench tend to live in the 8 kilometers depth and they decrease noticeably in number as that limit is crossed. The bottom of the pit was described by James Cameron as “a journey into absolute solitude.”
Among the living beings observed in the Mariana Trench are known:
- Giant unicellular protist microorganisms, belonging to the class xenophyophorea.
- Small crustaceans (amphipods) similar to shrimp.
- Fish with a gelatinous and flexible body, with large mouths and organelles to attract unsuspecting prey.
- Cephalopods and other small marine invertebrates, such as worms, sponges and jellyfish.
- Small eels and other elongated and translucent animals.
See also: Sea animals
Exploration and discoveries in the Mariana Trench
Since its discovery in the 19th century, the Mariana Trench has been an enigmatic place that poses a significant challenge to scientific navigation and exploration.
The first manned descent into its depths took place in 1960 through an underwater vessel captained by the Swiss explorer Jacques Piccard (1922-2008); and the most recent occurred in 2012 when the American film director James Cameron (1954-) reached the bed of the grave aboard the Deepsea Challenger submarine. There have been subsequent unmanned explorations of the trench by Russian scientists.
Among the most significant finds made in the Mariana Trench are:
- The deepest fish on the planet especially the Pseudoliparis swireiknown as the “Mariana snail fish,” an animal barely 20 cm long, with a translucent pink body and an incomplete skeleton.
- A group of giant unicellular protists known as xeophyophores, present only in the hadal zones of oceanic floors, about which not much is still known.
- A set of “giant viruses” unknown until now, belonging to the families Mimiviridae and Phycodnaviridaewhose size exceeds that of many species of bacteria.
- plastic garbage such as bags and other remains of human activity.
Continue with: Aquatic animals
References
- “Mariana Trench” on Wikipedia.
- “Ocean trench” on Wikipedia.
- “What's in the deepest place on the planet” in El Universal (Mexico).
- “Marianas Trench: images of Victor Vescovo's discovery, record for the deepest dive” on BBC News Mundo.
- “The Mariana Trench: Earth's Deepest Place” in National Geographic.
- “Mariana Trench (trench, Pacific Ocean)” in The Encyclopaedia Britannica.
