the largest ocean

The Pacific is the largest ocean basin, covering more than 155 million km², or about 30% of Earth’s surface (roughly 45% of the area covered by all oceans). The tropical Pacific plays a key role in El Niño and La Niña, which shift precipitation and temperatures across many regions of the world. The Mariana Trench lies in the western Pacific; its deepest known point is Challenger Deep, about 10,935 m according to one NOAA measurement.