Earth’s ocean is conventionally divided into five named regions—the Pacific, Atlantic, Indian, Arctic and Southern (Antarctic) Oceans—which together form a single interconnected global ocean
The five named oceans
The planet’s vast saltwater cover is commonly categorised into five oceans: the Pacific, Atlantic, Indian, Arctic and Southern (also called the Antarctic) Ocean, a classification based on geographic and oceanographic conventions.
Extent and volume
Oceans cover roughly 70 percent of Earth’s surface and contain about 97 percent of the planet’s water, forming the dominant reservoir of Earth’s hydrosphere and shaping global habitability.
Role in climate and circulation
Oceans play a central role in regulating the global climate by absorbing and redistributing heat and carbon, with large‑scale currents and exchanges between the atmosphere and sea governing weather patterns, heat transport and long‑term climate dynamics.
Biodiversity and human activities
The world’s oceans host immense biological diversity and complex ecosystems—from coastal estuaries to deep‑sea trenches—and support human activities including shipping, fisheries, recreation and scientific research that depend on healthy marine systems.
Interconnectedness and why it matters
Although mapped as separate oceans for descriptive and political reasons, they are physically connected by currents and water‑mass exchanges. This global connectivity means changes in one region can propagate and influence distant climates, ecosystems and human societies.
Takeaway
Together the five oceans form a single, dynamic global system that stores most of Earth’s water, sustains vast ecosystems and plays an indispensable role in climate regulation and human livelihood.