Oceanic basin

In hydrology, an oceanic basin (or ocean basin) is anywhere on Earth that is covered by seawater. Geologically, most of the ocean basins are large geologic basins that are below sea level.

Most commonly the ocean is divided into basins following the continents distribution^{[clarification needed]}: the North and South Atlantic (together approximately 75 million km²/ 29 million mi²), North and South Pacific (together approximately 155 million km²/ 59 million mi²), Indian Ocean (68 million km²/ 26 million mi²) and Arctic Ocean (14 million km²/ 5.4 million mi²). Also recognized is the Southern Ocean (20 million km²/ 7 million mi²). All ocean basins collectively cover 71% of the Earth's surface, and together they contain almost 97% of all water on the planet.^[1] They have an average depth of almost 4 km (about 2.5 miles).