Have you wondered what it’s like in the Challenger Deep, at the southern tip of the Mariana Trench in the Pacific Ocean? This is the deepest known point on Earth, with average depths at 10,902–10,929 m. We are talking a depth of over 2 km more than Mount Everest’s height. At this point, the water column above exerts a pressure of 15,750 pounds per square inch (psi), by which the density of water increases 4.96%. There is no sunlight and temperatures plummet well-below freezing, and yet life thrives here, and the challenge to reach the Challenger Deep has launched at least 22 expeditions to get here.
In 1960, US Navy Lt Don Walsh and Swiss oceanographer Jacques Piccard became the first humans to descend to the Challenger Deep, on board the bathyscaphe (self-propelled deep-dive submersible) ‘Trieste’. This monumental feat anchored interest in the ever-evolving field of oceanography, the study of the physical and biological properties and phenomena of the sea, a confluence of science and adventure. Even today, Lt Walsh is a passionate advocate of ocean exploration, an area of research that has intrigued generations.
For thousands of years, the urge to go deeper and deeper into the abyss has fascinated explorers. “Despite the fact that oceans cover approximately 70% of Earth’s surface and play a critical role in supporting life on our planet, from the air we breathe and the food we eat to weather and climate patterns, our understanding of the ocean remains limited,” says the US’ National Oceanic and Atmospheric Administration. We have only scratched the surface. It’s estimated that over 80% of the world’s oceans remain unexplored; and we know more about outer space than the inner ocean.
At the bottom of it
Scientists, anthropologists, conservationists, geologists and mystics argue that human connection with water is much deeper than land. Initially, it was for the fish. Thousands of years ago, Pacific island-hoppers dove into the shallow sea to hunt for food. As a curious species, we have always explored the unknown. This interest in the oceans for sustenance inspired the will to find what lay hidden across and under the vast body of water – for conquest, civilisation, economics, sport and science. Cutting-edge inventions, and the grit of the human spirit, took us to explore new worlds by sailing the seven seas, even as many took the plunge to go deeper.
As early as 1840, British Royal Navy officer Sir James Clark Ross carried out the first ocean deep-water sounding at 4,404 m in the South Atlantic Ocean, using the traditional method of lowering a hemp rope over the ship’s side. In 1872, the HMS Challenger expedition helmed a multidisciplinary undersea survey with the primary goal of discovering deep-sea life – we have gradually come a long way in touching the ocean bed. Subsequently, the invention of diving bells, scuba equipment, bathyspheres, submarines, submersibles, remotely-operated underwater vehicles and benthic landers, led us to watch deep marine ecosystems up-close.
In 1930, William Beebe and Otis Barton became the first humans to reach the deep sea in a bathysphere, reaching a depth of 435 m, where they observed jellyfish and shrimp. More recently, a Smithsonian Institution team filmed the elusive giant squid using a crittercam attached to a sperm whale, which preys on it. These cameras are not left to rust on the ocean floor, but are released from the suction on the cup fitted to the cetaceans, bringing them back to the surface to be retrieved. Similar ideas are used to explore oceanic mysteries, keeping in mind conservation and protection of marine ecosystems.