On March 26, 2012, Hollywood director James Cameron piloted the Deepsea Challenger to a depth of 10,898 meters, setting a world record for a solo dive to the deepest point in the ocean – the Mariana Trench.
Essential Facts About the Mariana Trench
The Mariana Trench, also known as the Mariana Abyss or Mariana Trough, is the deepest ocean trench known, and its deepest point is the lowest point on Earth’s crust. It is located at the bottom of the northwestern Pacific Ocean, east of the Mariana Islands. The coordinates of the deepest point are 11°21′ North and 142°12′ East. The trench extends toward Japan.
How was the Mariana Trench formed?
The Mariana Trench was formed by the collision of two tectonic plates (large plates of the Earth’s outer crust). This collision caused the older and larger Pacific Plate to subduct beneath the Mariana Plate.
The impact created a crescent-shaped trench on the ocean floor and a chain of nearby islands (the Mariana Islands). The islands were formed by volcanic eruptions caused by the intense release of water from the Pacific Plate.
The trench is approximately 2,550 km (1,580 miles) long but averages only about 69 km (43 miles) wide. The bottom of this trench is much deeper below sea level than the height of Mount Everest above sea level.
Cameron was the third person to achieve this honor. As a filmmaker, he took along a state-of-the-art 3D camera to capture rare footage from the deep sea.
Director James Cameron during the submarine expedition to the Mariana Trench.
The vivid images captured by Cameron’s skilled filming amazed scientists, revealing bizarre creatures existing in the deepest place known to humanity.
The Mariana Trench exceeds 10,000 meters in depth with extreme pressure and cold seawater. There is also no light penetrating down here, making the question of how life thrives in such harsh conditions a puzzling challenge for scientists.
Before the 19th century, humanity knew little about the ocean. What people imagined about the deep sea were merely fictional tales of monsters and civilizations coexisting with humankind, as depicted in the novels of French writer Jules Verne.
In Victorian England, scientist Edward Forbes experimented with dredging the Aegean Sea and found that the deeper one went, the fewer organisms existed. He concluded that there was no life below a depth of 550 meters.
However, from 1872 to 1876, the HMS Challenger embarked on a long voyage of 127,653 km to study and collect data on all the creatures inhabiting the oceans.
The deep sea is home to countless strange creatures.
A total of 4,700 new organisms were discovered, many of which live in the deep sea.
This expedition also revealed that the deepest point of the ocean was the dark crescent-shaped Mariana Trench located south of Japan.
The first expedition to the ocean’s deepest point occurred on January 23, 1960, conducted by oceanographer Jacques Piccard and U.S. Navy Captain Don Walsh.
The journey took 4 hours and 47 minutes. However, upon reaching the bottom, they were obscured by stirred-up sediments, limiting visibility. The only discovery made by the vessel was an organism that Piccard believed to be a flatfish but is now identified as a species of sea cucumber.
Life thrives in extreme conditions
Today, thanks to significant scientific advancements, humans have learned much more about the ocean and affirm that the ocean floor is indeed a place where life flourishes.
In late 2014, Jeffrey Drazen from the University of Hawaii in Honolulu led an expedition to the Mariana Trench.
Lanternfish with bioluminescent bodies to attract prey.
This journey left Drazen astounded by the biodiversity of the trench.
Due to the complete darkness at the trench’s bottom, organisms here have evolved in remarkable ways to adapt to their living conditions.
Some species possess enormous eyes to capture light more effectively. Others lack vision but are strong in their sense of touch to detect prey.
There are even species capable of bioluminescence to attract other prey.
The absence of sunlight prevents the growth of algae or plants, leading to a scarcity of food below. The primary food source for these organisms is derived from the decaying remains of fish and shrimp that sink from upper layers.
A strange crustacean found at the deep ocean floor.
The temperature here is also extremely harsh, ranging from -1 to 4 degrees Celsius. Even more frightening is that the pressure reaches eight tons per square inch, over a thousand times the normal pressure at the ocean surface.
The combination of extreme cold and pressure creates unusual effects on the bodies of these organisms.
All cells in these animals are surrounded by a layer of fatty membranes. This liquid membrane transmits nerve signals and facilitates the metabolic process from within to outside.
Strange creatures
James Cameron’s camera recorded crustaceans resembling shrimp, but much larger than their surface-dwelling counterparts.
The most commonly seen organism in Cameron’s footage was the giant single-celled organism.
Giant single-celled organisms thrive in extreme environments.
These organisms live in sediment layers at the bottom of the ocean worldwide, including in extremely harsh environments.
The footage also revealed organisms resembling a series of stick-like creatures buried in sand. Scientists recognized these as sea cucumbers due to their worm-like shape and numerous tentacles around the mouth.
Beyond these organisms, the most groundbreaking discovery at the ocean’s bottom is bacteria.
Gene structure analysis of these bacteria indicates that they exist by absorbing methane and hydrogen gases escaping from the ocean floor as geological tectonic plates in the trench rub against each other.
Scientists believe that the life of all organisms on Earth originated from long-term development and evolution from life forms at the ocean’s bottom.
Thus, the bacteria in the Mariana Trench may help scientists trace the origins of humanity.
Explorations of the Mariana Trench
The depth of the Mariana Trench was first measured in 1875 as part of the British Challenger expedition. This scientific exploration was conducted by the British and named after the naval ship involved – HMS Challenger.
Naval ship involved – HMS Challenger.
During the first Challenger expedition, the depth of the Mariana Trench was measured using a weighted sounding line. In 1951, the depth was re-measured. This time, the survey was conducted using the British naval survey ship Challenger II and more accurate echo-sounding equipment.
Only a few individuals have dived to the bottom of the Mariana Trench. The two pioneers in 1960 were Swiss engineer Jacques Piccard and U.S. Navy Captain Donald Walsh. In 2012, the dive was repeated by filmmaker James Cameron.
In 2019, a submarine named Limiting Factor descended into the Challenger Deep four times and into the Sirena Deep once as part of the Five Deeps expedition.
During two of these dives, including one record-breaking dive to a depth of 10,928 meters, ocean explorer Victor Vescovo made the descent solo.
Ocean explorer Victor Vescovo
Several unmanned underwater vehicles have been utilized to explore the Mariana Trench, including Kaiko in 1996 and Nereus in 2009.
