The deepest part of the ocean is 35,813 feet (10,916 meters) deep and occurs in the Mariana Trench in the Pacific Ocean. At that depth, the pressure is 18,000 pounds (9172 kilograms) per square inch.
The Mariana Trench is crescent-shaped in the Western Pacific, just east of the Mariana Islands near Guam. The region surrounding the trench is noteworthy for many unique environments. The Mariana Trench contains the deepest known points on Earth, vents bubbling up liquid sulfur and carbon dioxide, active mud volcanoes, and marine life adapted to pressures 1,000 times that at sea level.
The Challenger Deep, in the southern end of the Mariana Trench (sometimes called the Marianas Trench), is the deepest spot in the ocean. Its depth is difficult to measure from the surface, but modern estimates vary by less than 1,000 feet (305 meters).
In 2010, the Challenger Deep was pegged at 36,070 feet (10,994 m), as measured with sounds pulses sent through the ocean during a 2010 survey by the National Oceanic and Atmospheric Administration (NOAA).
In 2012, film director and deep-sea explorer James Cameron descended to the bottom of Challenger Deep, briefly reaching 35,756 feet (10,898 m) during the 2012 expedition. But he could have gone a little deeper. A high-resolution seafloor mapping survey published in 2014 by researchers from the University of New Hampshire said the Challenger Deep bottoms out at 36,037 feet (10,984 m).
The ocean's second-deepest place is also in the Mariana Trench. The Sirena Deep, which lies 124 miles (200 kilometers) to the east of Challenger Deep, is a bruising 35,462 feet deep (10,809 m).
By comparison, Mount Everest stands at 29,026 feet (8,848 m) above sea level, meaning the deepest part of the Mariana Trench is 7,044 feet (2,147 m) deeper than Everest is tall.