The ocean, a vast and mysterious realm, blankets approximately 70% of our planet’s surface. It stands as Earth’s largest habitable space, teeming with a biodiversity that surpasses any other environment. Yet, despite its critical importance, the majority of this underwater world remains largely unexplored. So, How Much Ocean Have We Explored, really?
Consider the sheer scale of the ocean: a surface area spanning roughly 360 million square kilometers (139 million square miles) and an average depth of 3,682 meters (12,080 feet). Life thrives throughout these depths, presenting an immense area for exploration and discovery. Our journey to understand this realm begins with mapping.
Seafloor mapping is essential. It gives us a sense of what lies beneath and helps guide exploration efforts, such as deploying submersibles like remotely operated vehicles (ROVs). While satellite data has been used to map the entire seafloor, this provides only a generalized view. These maps have limited detail, causing important geographical features like seamounts and objects like shipwrecks to remain hidden.
As of June 2024, approximately 26.1% of the global seafloor had been mapped using modern high-resolution technology. This technology primarily involves multibeam sonar systems. These systems are usually mounted on ships and are capable of revealing the seafloor in much greater detail. In comparison, almost 52% of the seafloor beneath U.S. waters has been mapped to these modern standards. However, the nation’s seafloor area is larger than the land area of all 50 states, the District of Columbia, and the five territories combined. Consequently, there is still a significant amount of seafloor that needs to be mapped at high resolution.
Interestingly, we know more about the seafloor’s topography than we do about the species that inhabit the ocean. Seafloor maps can provide clues about potential habitats, but they cannot identify the species living there or how they interact with their environments. Scientists estimate that the ocean may harbor between 700,000 and 1 million species (mostly animals, excluding the millions of microorganisms). Astonishingly, roughly two-thirds of these species, possibly more, have yet to be discovered or officially described. The scientific community accepts almost 2,000 new species each year, showcasing the ongoing discoveries in marine biology.
While we can quantify the extent of seafloor mapping and track the discovery of new species, it remains challenging to measure the overall extent of ocean exploration, encompassing both the seafloor and the water column. The ocean’s complex nature means that even with advanced technology, the true extent of its exploration remains elusive.
Despite the challenges, significant progress is being made. Each year, we expand our understanding of the ocean. New features and creatures are discovered, offering clues to our past and resources that can enhance our future. Although the ocean may never be fully explored, our continued efforts are vital, as Earth is constantly changing. Understanding these changes is crucial, given the ocean’s integral role in our everyday lives.
The ocean is a frontier of endless possibilities. While vast amounts of work remain, there is even more to discover, driving us forward in our quest to understand the depths of our planet.
