Why Has Only 42% of the Earth Been Explored?

Scientists attempt to further understand the ocean and its unknown areas

Space has caught the attention of many explorers due to its vast uncharted areas. Individuals looking to create change are drawn to the idea of extraterrestrial land and are slowly peeling away from investigating the earth. Society generally believes that the earth has been almost fully documented, and there isn’t much left to explore. However, this thought process couldn’t be more wrong. While a large portion of earth’s land has been recorded, the ocean is a completely different story. Almost 80% of the ocean has never been explored, mapped, or even seen by mankind. This is an unsettling thought on its own, not to mention the fact that 71% of the earth’s surface is made up of water; almost 58% of the world is unknown to the human race (1). This leaves many questions; most importantly, what tools have been used to explore the ocean thus far, and how can these be maximized to create further geographical change?

Although earth’s waters have been split up into seven different major seas, the planet has one global ocean. Oceanographers (people who study the ocean) have traditionally divided the waters into four distinct regions—the Pacific, Atlantic, Indian, and Arctic oceans. Some oceanographers have started labeling the seas around Antarctica the “Southern Ocean,” a term that was officially recognized as the fifth ocean by National Geographic in 2021 (1). The categorization of large bodies of water is incredibly important in order to avoid confusion and uncertainty. Approximately 97% of the earth’s water is located in the ocean, making it a vital resource to most organisms. Unfortunately, the ocean generally remains a mystery despite its importance to the fundamentals of life on earth. A larger portion of the moon and Mars’ surface has been studied and mapped than the contents of the earth’s waters (1). While there is still plenty to discover about the ocean, oceanographers have already collected some very important information. It is known that the ocean contains mountain ranges and canyons, more commonly known as trenches. While some of these solid formations break the surface, the oceans’ deep floors often prevent them from exiting the waters. The peak of Mount Everest (the tallest mountain on earth reaching its highest point at 29,035 feet) would not even break the surface if it was placed in the Mariana or Philippine Trench, two of the deepest parts of the ocean (1). 

The Mariana Trench is located in the Western Pacific Ocean (1)

Conversely, the Atlantic Ocean is relatively shallow as large parts of its seafloor are composed of continental shelves. Continental shelves are select parts of continents that extend out into the ocean, as seen off the coast of southern Maine in its Gulf. The average depth of the entire ocean is 12,200 feet (approximately the height of 15 John Hancock buildings stacked on top of each other), and contains 226,000 known species. While the actual number of inhabitants in the oceans is unknown, many oceanographers believe this number is dropping. Many marine ecosystems are suffering from rising sea temperatures, pollution, ever changing depth levels and other complications (1). 

The ocean is not only important for the human race, but is a home for thousands, if not millions of other species. This makes the preservation of its ecosystem integral to the survival of life on earth (1). Brainstorming and creating new ways to document data about the ocean is arguably the most important part of this process, a task taken on by National Geographic explorer and biorobotics expert Marcello Calisti. Calisti is currently developing an undersea exploration vehicle that uses “legged locomotion,” a tactic inspired by the way an octopus moves and operates underwater. Calisti’s goal is to design a robot that can explore depths of the ocean currently unreachable by humans (1). As explorers venture further and further away from the surface, they often characterize the ocean by zero visibility, extremely cold temperatures, and crushing amounts of pressure. The pressure of air compressing the body at sea level is 15 pounds per square inch, but these forces increase as one travels further underwater, reaching levels of 15,000 pounds per square inch (equivalent to the weight of 50 tractor trailers pressing on the body) (2). Dr. Gene Carl Feldman is an oceanographer at NASA’s Goddard Space Flight Center and is attempting to eradicate this roadblock entirely by eliminating the need for human-occupied submersibles to explore the waters (2).

Three ocean explorers seen operating a submersible in the Atlantic Ocean (2)

In order to reduce concerns about pressure, scientists have utilized their ability to chart the oceans from space. Feldman specializes in satellite technologies that record ocean color as a means of measuring phytoplankton levels, specifically the distribution and abundance of the substance. Phytoplankton are essentially a measure of the health of freshwater ecosystems. This kind of technology can capture detailed ocean images within minutes, a feat that used to take ships ten years of continuous sampling and collecting measurements (2). 

Scientists agree that exploring the earth is not only essential to societal advancements, but is fundamental to human life. While land above sea level and the terrain of many planets have been documented, the ocean remains relatively untouched and mysterious. Scientists have made great strides in technology related to ocean exploration, and continue to develop new and more efficient means of collecting geographical data. It would be unwise for researchers to advance in space exploration programs without first addressing the large portion of the world that is yet to be discovered and studied. Oceanographers are vastly uninformed about their region of study, but are doing all they can to turn this around. 


  1. National Geographic Society (2022, July 15). Ocean. NationalGeographic. Retrieved from


  1. Petsko, Emily. (2020, June 8). Why Does so Much of the Ocean Remain Unexplored and Unprotected?. Oceana. Retrieved from https://oceana.org/blog/why-does-so-much-ocean-remain-unexplored-and-unprotected/


  1. https://www.google.com/imgres?imgurl=https%3A%2F%2Fstatic.scientificamerican.com%2Fsciam%2Fcache%2Ffile%2FE2E9BDB3-5F41-4D2B-AB11BABC728F2A78_source.jpg%3Fw%3D590%26h%3D800%2681110826-6050-43BD-89BE3C6F5632727B&imgrefurl=https%3A%2F%2Fwww.scientificamerican.com%2Farticle%2Fthe-mariana-trench-is-7-miles-deep-whats-down-there%2F&tbnid=b27fHC-2KIC2RM&vet=12ahUKEwjszJHN4tb6AhVrrHIEHf2oBRAQMygAegUIARDdAQ..i&docid=qg8ZhTCI4YpjiM&w=590&h=447&q=the%20mariana%20trench&hl=en&ved=2ahUKEwjszJHN4tb6AhVrrHIEHf2oBRAQMygAegUIARDdAQ
  2. https://www.google.com/url?sa=i&url=https%3A%2F%2Fwww.superyachtnews.com%2Fowner%2Fthe-rise-of-submersibles&psig=AOvVaw3e6pFGF5y9KSWaJTFqdS25&ust=1665529471343000&source=images&cd=vfe&ved=0CAgQjRxqFwoTCIiSpIXj1voCFQAAAAAdAAAAABAD