Due to the difficulty of exploring the ocean floor, over the years, many myths and legends were formed around the Mariana Trench. From the presence of populations of the megalodon shark, a species of extinct gigantic shark that lived during the Cenozoic (if there is evidence that they lived there but not that they currently exist) and other giant prehistoric beings, until being the habitat of mythological sea monsters (such as the Kraken). For obvious reasons, none of these fables are true, but we cannot deny the imminent curiosity aroused by this particular moat in the middle of the ocean. One of the most curious data is that only 3 manned missions reached the bottom of the trench, therefore we have been more times on the moon on the real bottom of the seabed! Amazing, right? Exploring the Moon is easier than exploring the seabed of our own planet.
What is the Mariana Trench
The Mariana Trench is a depression on the seabed . It has a rounded shape and measures 2,550 kilometers long by 69 kilometers wide. As for how deep the Mariana Trench is , it is not yet known exactly. The truth is that there were many attempts to decipher the depth and, in fact, in 1985, the crew of the British ship HMS Challenger were the first to measure the trench, reaching a depth of 8,184 meters.
Today, the deepest known point of the Mariana Trench is 10,984 meters . Precisely this point is the deepest place on planet Earth known so far. For this reason and to honor the first ship that investigated the graves, at this point it was called Challenger’s Abyss .
This fascinating trench is located in the Pacific Ocean , south-east of the Mariana Islands , hence its name: Mariana Trench. The countries closest to the trench are Japan and China to the north, Taiwan, the Philippines and Indonesia to the east, and Papua New Guinea to the south.
As a curious and important fact, it should be noted that far from belonging to any of these countries, the Mariana Islands together with the Mariana Trench belong to the United States, even the trench was declared a National Monument of this country.
How the Mariana Trench was formed
Although it is not precisely known, experts say that the Mariana Trench was formed by subduction , a process by which a plate of the Earth’s crust sinks under the edge of another plate. In each subduction process a subduction angle arises, which in the case of the Mariana Trench is estimated to be approximately 90 °.
We must bear in mind that the Mariana Islands, together with the Mariana Trench, are part of the Pacific Ring of Fire , which is known to concentrate some of the most important subduction zones in the world that cause great seismic and volcanic activities. It is believed that the subduction that gave rise to the Mariana Trench involves the Pacific plate that subducts under the Philippine plate .
What’s in the Mariana Trench
Like everything related to this extraordinary marine depression, it is not known precisely what is at the bottom of the Mariana Trench . With regard to biodiversity, it seems that the environment of the Mariana trenches is not conducive to life: extremely high pressure, low temperature and darkness that once the first meters have passed is absolute. However, many research efforts made it possible to discover that there is life in the trench and, therefore, in this section we will talk about the fauna of the Mariana Trench .
According to the U.S. National Oceanic and Atmospheric Administration Office , the trench can be divided into three sections:
- First layer: covers from the surface to about 200 meters deep. Sunlight penetrates through this layer and coral reefs were observed as in other parts of the planet.
- Second layer: it ranges from the end of the first layer to 600 meters deep. Here volcanoes were found and also animals common in other areas of the ocean with the same depth.
- Third layer: it goes from the end of the second layer to the Challenger Abyss, being the most enigmatic part of the pit. There were sea cucumbers, amphipods (small crustaceans), more than 200 species of microorganisms and xenophiophores. Within the animals of the Mariana Trench , xenophiophores are the most difficult to study. They are giant unicellular organisms that by their appearance resemble sea sponges and are highly specialized to live in extreme conditions.
Finally, it should be noted that during 2019 plastic remains were found at depths never before imagined. This raises the question of how far pollution caused by human activities can go.