The World's Deepest Crack

By Aerin Choy

The deepest part of the ocean is the Mariana Trench, with a maximum depth of approximately 11 kilometers, it itself is deeper than Mount Everest is tall. Within the trench, the deepest point is called Challenger Deep (10,935 meters deep). Humans only visited this elusive place in 1960 when US Navy Lieutenant Don Walsh and Swiss oceanographer Jacques Piccard accomplished this. The achievement came nearly 100 years after the discovery by the British Royal Navy in 1875. The Director of the Titanic James Cameron also did a solo dive in the trench in 2012. The trench is an official US monument due to its proximity with the US territory of Guam. 

The Mariana Trench was formed at a subduction zone where one piece of the ocean crust slid under the other, sinking into the mantle, in this instance the Pacific Ocean crust slid under the Philippine crust.

Initially, using sound waves, the depth was approximated at 8,184 m in the 1870s, later on it was assumed that there was an even deeper point called Nero Deep (9,660 m) The depth continuously increased as technology developed, in 1984 the Japanese expedition team recorded a depth of 10,916 meters which actually was verified by US scientists in 2011 (“Undersea Exploration”).

Organisms which live in the trench are able to withstand low temperatures and high pressure but from a human’s perspective a trip down to the trench would just be in complete darkness. Areas which are found in ocean trenches below 6,000 meters are called Hadal Zones, before comprehensive scientific study many assumed that these areas would be devoid of life yet as research progresses the true diversity of these ecosystems are being revealed.  Deep Sea Life such as foraminifera, a type of plankton was discovered at Challenger Deep in 2005 and various sea cucumbers have also been discovered. The ocean floor is noted for the existence of undersea volcanoes, despite the high heat and acidic conditions, extremophiles exist within those areas, feeding off the nutrient rich spews of undersea volcanoes (Oskin). 

Some adaptations organisms have include monochromatic vision, their eyes have been adapted to see a limited number of wavelengths. Looking at the genes of hadal snail fish, researchers in China discovered that genes for circadian rhythm have been lost, possibly due to the lack of sunlight in the depths of the ocean. The skull of the hadal snail fish was not completely enclosed due to the pressure in the trench (Wang and Yang) . Much more exploration is needed to truly ascertain the wonders of the Challenge Deep. 

Given how untouched these depths are, there should be no trace of humanity; however, in the last 10 or so years, plastic candy wrappers, beer bottles and more have been discovered in the area, igniting sorrow about how our consumption has negatively degraded the Earth even though we may not have visited a place before. It strikes a poignant image of how wonderful our world is today. 

Some Fun Facts ;)

• The Mariana Trench is older than humans! While human exploration of the trench started in the 20th century, this part of the ocean has existed for millions of years, forming long before any human set foot on Earth.

• Pressure in the trench is intense! The pressure at Challenger Deep is over 1,000 times greater than at sea level, equivalent to the weight of 50 jumbo jets stacked on top of you!

• The trench is the "Amazon rainforest of the deep sea." Despite its extreme conditions, the Mariana Trench is teeming with life. Researchers have discovered more than 300 new species living there, including bizarre creatures like the "Hadal Snailfish."

• The trench could be home to a "lost city." Some scientists believe the trench could be hiding ancient, undiscovered ecosystems that might hold secrets to our planet's early life or even new medical breakthroughs.

• The trench is the Earth's natural "garbage dump." It’s been reported that trash, including plastic wrappers and bottles, has made its way into the trench, underscoring the growing problem of ocean pollution.

• Deep sea creatures have some seriously weird features. Many creatures that live in the Mariana Trench are bioluminescent, meaning they can create their own light in the pitch-black depths a handy feature for survival in the dark!

• The trench is like the "Mount Everest of the Ocean." Just as Everest is the highest point on Earth, the Mariana Trench is the deepest. It's like nature’s extreme version of a mountain range... just underwater!

• The pressure is so intense, your body would shrink! If a human were to descend to the Challenger Deep without the proper protection, the immense pressure would actually compress their body, making them shrink by a few inches!

• Titanic’s director James Cameron went to the bottom. The filmmaker who brought the Titanic disaster to the big screen took a solo trip to the bottom of the Mariana Trench in 2012. Talk about an adventure worthy of a movie!

• The trench could help us understand life on other planets. Because of its extreme conditions, life in the trench is studied by scientists to understand how organisms might survive on planets with similar harsh environments, like Mars or Europa.

  
  

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Works Cited

“Mariana Trench | Smithsonian Ocean.” Ocean.si.edu, ocean.si.edu/planet-ocean/seafloor/mariana-trench.

Meinch, Tree. “What Has Been Found in the Deep Waters of the Mariana Trench?” Discover Magazine, 29 Nov. 2023, www.discovermagazine.com/planet-earth/what-has-been-found-in-the-deep-waters-of-the-mariana-trench. Accessed 1 Apr. 2025.

Oskin, Becky. “Mariana Trench: The Deepest Depths.” Live Science, Live Science, 6 Dec. 2017, www.livescience.com/23387-mariana-trench.html. Accessed 1 Apr. 2025.

“Undersea Exploration.” Encyclopedia Britannica, www.britannica.com/technology/undersea-exploration. Accessed 1 Apr. 2025.

Wang, Ying, and Liandong Yang. “Surviving under Pressure.” ELife, vol. 12, July 2023, p. e90216, https://doi.org/10.7554/eLife.90216. Accessed 1 Apr. 2025.