Over the course of a century, expeditions have continued, trying to probe the depths of the Mariana Trench, reach its deepest point at its bottom, and discover its exciting secrets and strange creatures.
And recently, the "Live Science" website published a long article about this trench that contains many amazing information.
What are the deepest areas of the Mariana Trench?
The crescent-shaped Mariana Trench contains the deepest area of the oceans and the two deepest spots on the planet, in the western Pacific Ocean, east of the Mariana Islands near the island of Guam (US).
The length of the Mariana Trench is 2,542 km, which is 5 times larger than the Great Trench in the US state of Arizona, but the Mariana Trench is narrower, as its maximum width does not exceed 69 km.
The area around the trench is famous for its many unique environments, with outlets for liquid sulfur and carbon dioxide to flow, active mud volcanoes and marine creatures that have adapted to sea pressure that is a thousand times greater than pressure at sea level.
At the southern end of the Mariana Trench is the Challenger Deep, with the deepest point in the ocean (NOAA).
At the southern end of the Mariana Trench there is an area called Challenger Deep, which has the deepest point in the ocean. It was difficult to measure its depth from the surface, but in 2010 the US National Oceanic and Atmospheric Administration (NOAA) used pulse technology. The sound waves across the ocean and determined the depth of the "Challenger Deep" at a distance of 10,994 meters.
In 2021, measurements using pressure sensors found that the deepest point in the Challenger Deep is 10,935 meters from the surface, and other estimates ranged from distances less than 305 meters.
As for the second deepest spot in the ocean, it is also in the Mariana Trench, and it is called “Sirena Deep.” It is 200 km from Challenger Deep, and its depth is 10,809 meters. In comparison, this depth is 2,147 meters greater than the height of the summit of Mount Mt. Everest, which is 8,848 meters above sea level.
Who simplifies his control over the Mariana Trench?
Since the island of Guam is an American region, and the 15 Northern Mariana Islands are under the control of the American Commonwealth, the Mariana Trench is under the influence and control of the United States of America. square kilometres, including the seabed and the waters surrounding the outlying islands.
Comparison between the height of the highest point on land (Gill Everest) and the longest depth in the sea (Mariana Trench) (the island)
How is the Mariana Trench formed?
The Mariana Trench was formed due to a geological process that occurs in areas called subduction zones, which are formed as a result of the collision of two huge plates of ocean crust with each other, pushing one of the other and sliding under it and sinking into the mantle layer (which is the layer that lies under the Earth's crust).
Because of the overlapping of these two plates, a deep trench was formed above the bend in the crust below.
In the case of the Mariana Trench, it was formed as a result of the Pacific crust slipping and flexing under the Philippine crust.
While the crust of the Pacific Ocean is 180 million years old and sinking into the trench, the crust of the Philippines is younger and smaller than the crust of the Pacific Ocean.
Despite the enormous depth of the trench, it is not closer to the center of the Earth, and because our planet is dented at the equator, the distance between the poles and the center of the Earth is about 25 kilometers less than at the equator, so the bottom of the polar ocean is closer to the center of the Earth than the Challenger Deep.
The massive water pressure at the bottom of the trench is over 8 tons per square inch (703 kilograms per square metre), a pressure more than a thousand times the pressure you feel at sea level, or the equivalent of 50 jumbo jets above a person.
Has anyone succeeded in diving to the depths of the Mariana Trench?
Over the past decade, numerous manned and unmanned scientific expeditions have explored the Mariana Trench and competed to break the record for reaching the deepest depths of the abyssal bottom.
In 1875, the trench was first discovered by the HMS Challenger using modern sounding equipment, during a circumnavigation of the globe.
In 1951, another ship named "HMS Challenger 2" examined the trench again, and in honor of these two ships the name "Challenger Deep" was given to the deepest part of the trench.
The first human-led submarine to reach the depths of the Challenger Deep was the Trieste submarine, which made this trip in 1960 and was led by US Navy Lieutenant Don Walsh and Swiss scientist Jacques Piccard. The vehicle reached a depth of 10,911 meters.
In 2012, James Cameron, the famous film director, solo piloted the Deepsea Challenger to reach the bottom of the Challenger Deep at a depth of 10,000,908 meters, and filmed a documentary about the depths of the trench for National Geographic.
In 2019, explorer and entrepreneur Victor Veskovo drove another vehicle called DSV Limiting Factor, to break the record for the deepest dive in the Challenger Deep, reaching a depth of 10,927 metres.
Other than manned flights, there have been unmanned flights into the trench by robotic submarines to expand the limits and horizons of human knowledge around these abyssal depths of the ocean.
In 1995, the Japanese Navy submarine Kaiko collected samples and data from the trench, and in 2009, the US double-dip remote-operated submarine Nereus reached the depths of the Challenger Deep, and has been recording video for 10 hours.
In 2021, the Spanish Caladan Oceanic Expedition "Ring of Fire Expedition - Part II" collected mantle rocks deep in the Mariana Trench containing microbial mats.
What creatures live in the Mariana Trench?
Recent scientific expeditions have revealed thriving, astonishing life in the abyssal depths of the Mariana Trench and other similarly extreme conditions, described by Natasha Gallo, a doctoral researcher at the Scripps Institution of Oceanography, who studied video recorded by film director James Cameron's expedition in The trench in 2012, saying, “Food in the Mariana Trench is very scarce because the strait is so deep from the ground, and terrestrial plants rarely make their way to the depth of the trench, and the dead plankton organisms (plankton) drowning from the surface have to cross thousands of feet to reach the depths in the area. Challenger Deep.
But some microbes depend for their diet on chemicals, such as methane and sulfur, while other creatures devour marine organisms lower than them in the food chain.”
CT scan of snails that live at the bottom of the Mariana Trench (Adam Summers - University of Washington)
The most common organisms deep in the Mariana Trench, says Natasha Gallo, are xenophyophores, amphipods and small sea cucumbers, the latter of which have been observed in great abundance at the depths.
Xenophyphora resemble giant amoebas, and they eat food by enclosing and then absorbing their food. Amyopods are shiny, shrimp-like creatures that are abundant in the depths, but their ability to survive in this terrible pressure is puzzling because the shells of these creatures would easily dissolve under the pressure of high pressure in a trench Mariana.
But in 2019, researchers discovered that several types of creatures inhabiting the Mariana Trench use aluminum extracted from seawater to reinforce their shells.
During the James Cameron scientific expedition in 2012, scientists noticed what looked like microbial mats in the Serena Deep, which lies to the east of the Challenger Deep, and these microbial masses feed on hydrogen and methane released by chemical reactions between seawater and rocks.
One of the most powerful predators in the region is a fish with a meek and deceitful shape. In 2017, scientists reported that they had collected samples of a strange fish they called "Mariana snailfish", which lives at depths of up to 8 thousand meters.
The fish's small, pink, scaleless body seems barely able to survive in this harsh environment, but this fish was full of surprises that the researchers recorded in a research paper published in the journal "Zootaxa".
The researchers said that fish dominate this ecosystem with their ability to go to depths that no other fish can go to, and to take advantage of the absence of competitors by devouring the abundant vertebrates that inhabit the bottom of the trench.
Has pollution reached the Mariana Trench?
Unfortunately, the depths of the oceans have become a repository of abandoned garbage and pollutants, including the Mariana Trench.
In a study published in Nature Ecology and Evolution in 2017, a team of researchers at Newcastle University, UK, demonstrated that man-made chemicals banned in the 1970s still lurk in the deepest regions of the ocean.
In another study published in the same journal, researchers discovered, while sampling amphipods (such as shrimp) in the “Mariana” and “Kermadec” trenches, high levels of stubborn organic pollutants in the tissues of fatty creatures, including PCBs and PBDEs. They are chemicals commonly used in electrical insulating materials and flame retardants.
These stubborn organic pollutants were seeped into the environment in industrial accidents and landfill leaks during the period from the 1930s to the 1970s, when they were banned altogether.
The researchers found that the amphipods examined in the study had high levels of pollution similar to those in Suruga Bay, one of the most polluted industrial areas in the Pacific Northwest.
The density of microplastics in the deep sea is now much higher than previously thought (Shutterstock)
Because stubborn organic pollutants do not decompose naturally, they persist in the environment for decades, reaching the depths of the ocean through polluted plastic waste and dead animals, and the pollutants move from one organism to another through the ocean food chain, ultimately resulting in extremely high concentrations of chemicals that are much higher of pollution level on the surface.
The Mariana Trench itself is no longer safe from the plastic pollution that invades the world's oceans, and a research paper published in the journal "Geochemical Perspectives" found that microplastic particles are scattered in the lower currents of the Mariana Trench, which confirms that these plastic pollutants have permeated From the ocean to concentrated in the abyssal depths.
In a sad press release, Alan Jamieson, Senior Lecturer in Marine Environments at Newcastle University and lead researcher on the study, said: “We used to think that the ocean depths in this remote and clear region were safe from human influence, but our studies confirm that unfortunately, that perception has become "This is completely untrue. Finding such extreme levels of these pollutants in one of the most isolated and inaccessible marine environments on Earth clearly demonstrates the devastating long-term impact humans have had on the planet."