It’s astonishing that we have more detailed maps of the moon than of our deep ocean floor. The moon’s surface is easier to observe, as it lacks the vast deep ocean that obscures our view of Earth’s underwater terrain.
With a telescope on a clear night, anyone can glimpse the moon’s features, especially on the side visible from Earth. Interestingly, the moon is roughly one-tenth the size of the deep ocean floor, which encompasses two-thirds of our planet’s surface.
The deep ocean covers an extensive area of over 335 million square kilometers (approximately 129.3 million square miles). Its inaccessibility, combined with the vastness of the ocean, explains why, despite our advanced technology, only a fraction has been explored.
Recently, a dedicated team of scientists compiled a comprehensive dataset containing data from around 44,000 dives into the deep ocean. These dives were conducted using submarines, remotely operated vehicles (ROVs), and autonomous underwater robots.
These deep-diving vehicles have collectively documented less than 0.001% of the deep-sea floor, comparable to the area of Rhode Island, the smallest U.S. state. If we applied similar statistics to terrestrial exploration, our entire understanding of ecosystems would come from an area only as large as the London metropolitan region.
Moreover, the minuscule part of the ocean floor studied is a highly biased sample. In fact, 65% of deep-sea exploration dives happened within 200 nautical miles of the United States, Japan, or New Zealand. Nearly all deep-seafloor observations (around 97%) were conducted by these three countries, in addition to France and Germany.
Additionally, explorers have mainly concentrated on a narrow spectrum of deep-sea features, dedicating significant research to rugged marine landscapes such as deep canyons and cliffs while neglecting regions like the expansive abyssal plains.
The Global Dive Dataset also highlights a critical limitation: dive depth. While the number of dives has increased over the decades, the depths have generally become shallower. In the 1960s, over half of dives surpassed 2 km (about 1.2 miles) deep, but by the 2010s, only a quarter of dives reached that depth.
This is concerning because approximately 75% of the ocean lies between 2 km and 6 km (1.2 miles and 3.7 miles) beneath sea level, indicating that significant portions of the ocean floor remain uncharted.
Clearly, contemporary deep-sea explorations overlook vast areas, leaving much of the ocean unexplored and unknown. Various initiatives are underway to enhance access to deep-sea tools and dive into less-known locations to discover what lies beneath the global deep ocean.
This article responds to Charlotte Preston of Southampton, who asked: “How much of the ocean floor have we actually explored?”
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Source: www.sciencefocus.com
