The ocean is 12,100 feet deep on an average. (Representational image: Reuters)

Challenger Deep: A few days ago, Kathy Sullivan, the first American woman to walk in space, became the first woman in the world to dive to Challenger Deep, the deepest point in the ocean known to man. Challenger Deep is in the Mariana Trench, around 11 kms under the surface of the Pacific Ocean. Kathy Sullivan also became only the fifth person in history to achieve the feat, according to a report in IE. The report added that she is the only person to have walked in space and reached the deepest point in the ocean.

Kathy descended to the Challenger Deep in a submersible, vehicle operable under water, ‘Limiting Factor’ as a part of the Ring of Fire Expedition by Caladan Oceanic. As per the report, the expedition team has been hoping to observe volcanic vents, conduct the mapping of the Exclusive Economic Zone of the US as requested by the National Oceanic and Atmospheric Administration (NOAA) and identify new species.

Challenger Deep explained

US’s NOAA has explained that the ocean is 12,100 feet deep on an average. However, the deepest part, or Challenger Deep, located in the western Pacific Ocean at the southern end of Mariana Trench, is at an approximate depth of 36,200 feet, the report said. The depth was first sounded in 1875 by the crew of British ship HMS Challenger, from which this point got its name.

As per the IE report, the first dive to the deepest point in the ocean took place in 1960 by Swiss scientist Jacques Piccard and Lieutenant Don Walsh on the submersible ‘Trieste’. Interestingly, in 2012, Titanic director James Cameron also reached the bottom of Mariana Trench after a 2 hours 36 minutes long descent. He descended in his submersible ‘Deepsea Challenger’ and dove to a depth of 10,908 kms, scripting history by becoming the first person to complete a solo submarine dive to the spot, according to the report.

Scientists’ interest in ocean depths

The IE report, citing NOAA, stated that the present knowledge about the oceans stems from the shallower waters and the deeper ones are relatively unknown. Still, humans mainly rely on these deeper areas for energy, food and other resources, the report stated.

The report also stated that more information about the deep ocean could potentially lead to the discovery of sources for medicinal drugs, energy sources, food and other products. Moreover, it could also help in prediction of tsunamis and earthquakes, also helping the humankind understand how the Earth’s environment is affecting us and getting affected by our activities, the report added.

How can one reach the deep ocean?

The IE report states that scientists can be carried to the deep sea by vehicles called human occupied vehicles (HOVs), or, alternatively, unmanned vehicles, called remotely operated vehicles (ROVs) can also be used. ROVs are linked to the ships via cables and scientists can steer them remotely.

However, the report added, most private citizens cannot dive deeper than 120 feet because of the amount of air that is needed at the depth to keep the lungs pressurised at that depth. Moreover, nitrogen narcosis, the intoxication caused by the nitrogen which starts to set in at that depth, is also a factor which hinders private citizens’ dives beyond that.