The Pacific Ring of Fire is a massive area around the edge of the Pacific Ocean where most of the world’s volcanic and seismic activity occurs. Just south of Japan, at a maximum depth of 11,034m, lies the deepest point on the surface of the planet: the Challenger Deep.
This depression in the seabed is located at the southern end of the Mariana Trench, the geological product of the convergence of two tectonic plates -the Pacific Plate and the Mariana Plate – and a process called subduction whereby the larger and denser of the two converging plates (that being the Pacific Plate) gets subducted under the Earth’s mantle, creating a deep depression in the Earth’s crust. These trenches make up the deepest parts of the world’s oceans -and for this reason such areas remain practically uncharted.
Less than five per cent of the world’s oceans have been explored due to the inaccessible nature of deep sea (the lowest layer in the ocean) and the massive pressure (some 16,000psi) exerted on objects at these depths.
In 1960, however, intrepid oceanographers Jacques Piccard and Lt Don Walsh ventured to the bottom of the Mariana Trench in a bathyscaphe called the Trieste: the only manned submersible to reach the bottom and return in tact. Although the men could not collect photos, data, or samples from the seabed, their voyage provided a new vision of what could be achieved in deep-sea exploration.
More often these days, unmanned, remotely operated submarines and observation vessels are used for locating, mapping, collecting and photographing deep-sea geology and biology. In this pitch-black world it is extremely cold and the pressure of the seawater above makes for a very inhospitable environment for marine life let alone eager explorers. However, each new dive seems to uncover another species of aquatic life in this unique underwater ecosystem and with new developments in submersible vehicles we are drawing ever closer to uncovering more of this, the unfathomable deep. Right now, we’ve only scratched the surface.