Many who have heard about the area known as the deepest point in the Pacific Ocean would ask: how deep is the Mariana Trench and why is it considered to be so important? Before answering that, we have to look at what the trench itself really is and represents. It is also meaningful to take a closer look at the actual geological events that have led to the formation of the trench, as well as the discovery of the trench and the numerous measurements associated with it.
Marianas Trench – as it is also known as – is not only the deepest part of the Pacific Ocean, but also the deepest point of any ocean in the world. The trench, measuring more than 30,000 feet in depth, features a water temperature of 1-4 C – which is not considered to be extreme at all. But the most impressive of its traits is the crushing water pressure level present around its deepest regions, reaching more than 15,000 psi – 1,000 times the atmospheric pressure above sea level. More than 2,500 km in length, the trench has been explored and analyzed by many researchers in the past 50-60 years, some of whom have also concluded that microbial life forms could be thriving on the ocean floor, even in the deepest regions of the trench.
After several different measurements performed throughout the past century, the sonar mapping of the region completed in 2009 by scientists aboard the RV Kilo Moana has revealed the true depth of the Mariana Trench – 10,971 meters, or 35,994 feet. More recent measurements have concluded that the trench is actually 10,994 meters deep (while unrepeated checks have even been claimed to point to a depth of 11,030 meters); however, these last measurements were considered somewhat less accurate. The Challenger Deep – the Mariana Trench’s deepest known point – was first explored by Don Walsh and Jacques Piccard in 1960.
Although the trench is, thus far, the deepest known point in any ocean on Earth, it is not the closest to the center of the Earth, due to the planet being an imperfect sphere. Nevertheless, at 2,550 km long and 69 km wide, it is definitely one of the most impressive geological structures on our planet. Located between two tectonic plates – the Pacific and the younger Mariana plate – the trench is considered to be roughly 170 million years old, the movement of the plates also known to be responsible for the formation of the nearby Mariana islands.
The Royal British Navy conducted the first measurements in the Mariana Trench as early as 1875. Without the use of sophisticated equipment, they still managed to measure a maximum depth of about 8,184 meters. 76 years later, another Royal Navy vessel conducted measurements in the region, discovering an even deeper point of about 10,900 meters – very close to the officially accepted depth of the Challenger Point.