As the deepest and darkest location on Earth, the Mariana Trench is the home to many unusual marine life and insane chemical reactions. The trench is crescent shaped, and located in the Western Pacific Ocean, east of the Mariana Islands near Guam.
So how deep exactly is the deepest point on Earth? The Challenger Deep is the deepest point within the trench and depths this low are impossible to measure in person due to the crushing pressures of the sea. James Cameron (the guy who directed Titanic who happens to also be a deep-sea explorer) reached the bottom of Challenger Deep at 35,756 feet during a 2012 expedition. However, researchers from the University of New Hampshire used a high-resolution seafloor mapping survey to conclude that Challenger Deep is actually 36,037 feet deep. It is extremely difficult to comprehend how deep that actually is. By comparison, if you were to drive 6.83 miles down the road, that’s equivalent to driving to the bottom if the Mariana Trench. Also, the notoriously tall Mount Everest stands at only 29,026 feet, a mere 7,044 feet shorter than the trench is deep. Also, the trench is 1,580 miles long, which is more than five times the length of the Grand Canyon. Its enormous depth magnitude causes an immense increase in pressure: about 8 tons per square inch. There is more pressure on the bottom of the Mariana Trench than 1,000 times the pressure felt at seas level, which is the equivalent to 50 jumbo jets piled on one person.
The next question to ask is: how was this trench formed? Simply speaking, the Mariana trench formed when two plates on the Earth’s crust collided in the subduction zone, which is the biggest collision sight on the Earth’s surface. According to Nicholas van der Elst, a seismologist at Columbia University, the cold, dense crust sinks back into the mantle and is destroyed at subduction zones. In this case, one piece of oceanic crust is pulled underneath the other and sinks into the Earth’s mantle. This process causes the trench to form above the bend as one plate sinks into the Earth.
Surprisingly enough, scientists have found that there is a very diverse community of marine life that live at the bottom of the Mariana Trench. Food is extremely rare at the bottom because most sources hardly ever make it to the complete bottom of the ocean floor. Accommodate for this scarcity, some microbes feed on chemicals like methane or sulfur, while others scour for other marine life lower on the food chain. There are three organisms most commonly found on the bottom of the trench: xenophyophores, amphipods, and holothurians. The xenophyophores are single-celled organisms similar to a giant amoeba, and gain their nutrition by surrounding and absorbing their food. Amphipods are shrimplike scavengers and the holothurians are a new species of bizarre, luminous sea cucumber. In the Challenger Deep, there are also 200 different microorganisms that have been identified in mud and feed on hydrogen and methane released by chemical reactions between seawater and rocks.
Unfortunately, the Mariana Trench isn’t as easily available as a vacation destination like the other places I’ve written about, but it’s still an amazing feature of our Earth that not many people know about.