The Pacific Ocean, the largest and deepest of Earth’s oceanic divisions, covers approximately 46% of the planet’s water surface. With an average depth of 4,000 meters (13,000 feet), it plunges to its deepest point in the Challenger Deep of the Mariana Trench, reaching 10,911 meters (35,797 feet). This vast ocean holds many mysteries, prompting ongoing efforts to understand how much of it has truly been explored.
Defining Ocean Exploration
Ocean exploration studies the marine environment, including bathymetry, biological surveys, geological investigations, and chemical analysis. Bathymetry charts the seafloor’s shape and depth, similar to land topography. This process is crucial for understanding the underwater terrain, which can include mountains, canyons, and plains.
Biological surveys discover marine species, from microscopic organisms to large marine animals. Geological studies delve into the formation and composition of the ocean floor, examining features like hydrothermal vents and seamounts. Chemical analysis of the water column provides insights into ocean processes and nutrient cycles. Different technologies are employed, with sonar systems used for broad seafloor mapping and specialized equipment like remotely operated vehicles (ROVs) and autonomous underwater vehicles (AUVs) for detailed deep-sea investigations.
Current Exploration Status
While satellite data provides a general overview of the global seafloor, its resolution is often insufficient for detailed features. As of June 2024, only about 26.1% of the global seafloor has been mapped using high-resolution multibeam sonar technology. This method offers detailed imagery, but much remains unmapped.
Visual exploration of the deep seafloor and the water column, often conducted using submersibles or ROVs, covers an even smaller percentage. For example, the Papahānaumokuākea Marine National Monument, one of the world’s largest marine conservation areas in the Pacific, has had only about 3% of its seafloor explored. The Nippon Foundation-GEBCO Seabed 2030 Project is a global initiative working to achieve a complete, high-resolution map of the entire ocean floor by 2030, to fill these knowledge gaps.
Challenges of Deep-Sea Exploration
The Pacific Ocean’s vastness presents considerable obstacles to comprehensive exploration. The deep sea is characterized by extreme conditions, challenging equipment and human operations. Immense pressure is a primary concern, increasing significantly with depth; at 7,000 feet, the pressure can be more than 800 times that at sea level. This crushing force necessitates robust vehicles.
Deep-sea environments are also marked by frigid temperatures, often near freezing, and absolute darkness, as sunlight cannot penetrate beyond approximately 1,000 meters (3,280 feet). The corrosive nature of seawater further complicates equipment design and maintenance. High costs for specialized deep-sea equipment like ROVs and AUVs, along with logistical difficulties in remote regions, make sustained exploration complex.
Unveiling the Unknown
Despite challenges, Pacific Ocean exploration yields discoveries. Many new species await discovery; scientists estimate that between 700,000 and 1 million species inhabit the ocean, with many still unknown. Recent expeditions in the Southeast Pacific have already identified over 100 potentially new species, including unique octopuses and deep-sea corals. More than 5,000 new species have been found in the Clarion-Clipperton Zone, a deep-sea area in the Pacific.
The deep Pacific also holds undiscovered geological features, such as new hydrothermal vents and seamounts, which are underwater mountains that often host diverse ecosystems. A previously unknown seamount rising over 3,000 meters was recently found off the coast of Chile. These discoveries expand understanding of marine biodiversity and geology, and provide insights into Earth’s fundamental processes. The deep ocean plays a role in regulating global temperatures and absorbing carbon dioxide, highlighting the value of continued oceanographic research for understanding the planet’s ecosystems, resources, and climate history.