Oceans and the movement of water
Oceans form a connected body of salt water covering much of the Earth's surface. Names given to individual oceans help describe different regions, but the water does not stop at those boundaries. Connections between basins allow heat, dissolved substances, and living organisms to move over great distances. The ocean is also closely linked to the atmosphere and to the land through the continuing movement of water. Conditions vary greatly between the surface and deeper water. Sunlight reaches the upper layers most strongly and becomes weaker with depth. Surface waters respond to weather and can be moved by wind. Far below, the environment is darker, colder in many regions, and subject to greater pressure. The depth and shape of the seafloor introduce further differences, including broad plains, underwater ridges, and deep…
