Pacific Ocean

In terms of size and depth, the Pacific Ocean is the biggest and deepest of the world's five oceanic divisions. This oceanic region stretches northward from the Arctic Ocean and southward to the Southern Ocean and Antarctica, and is bordered on the west by the continents of Asia and Australia and on the east by the continents of North and South America and the Pacific Ocean.

When measured in square kilometres, this greatest division of the World Ocean—and hence the hydrosphere—covers around 46 percent of Earth's water surface and approximately 32 percent of the planet's total surface area. It is bigger than the whole land surface of the planet put together (148,000,000 square kilometers). Located in the Pacific Ocean are the geographic centres of both the Water Hemisphere and the Western Hemisphere. Ocean circulation (produced by the Coriolis effect) separates the ocean into two mostly independent quantities of water that meet near the equator: the North(ern) Pacific Ocean and the South(ern) Pacific Ocean. The North(ern) Pacific Ocean is larger than the South(ern) Pacific Ocean. Despite the fact that the Galápagos and Gilbert Islands are located on each side of the equator, they are considered to be entirely inside the South Pacific.

This body of water averages 4,000 metres in depth (13,000 feet). Challenger Deep, situated in the Mariana Trench in the western north Pacific, is the world's deepest point, reaching a depth of 10,928 metres. It is the deepest point on the planet (35,853 feet). The Pacific Ocean also has the Horizon Deep in the Tonga Trench, which is the deepest point in the Southern Hemisphere at 10,823 metres below sea level (35,509 feet). This region also contains the Sirena Deep, which is the third-deepest point on the planet and is situated inside the Mariana Trench.

Several major marginal seas can be found in the western Pacific, including, but not limited to, the South China Sea, the East China Sea, the Sea of Japan, the Sea of Okhotsk (also known as the Bering Strait), and the Philippine Sea. Other marginal seas include the Coral Sea, the Java Sea, the Tasman Sea, and the Coral Sea, which are all located in the western Pacific.