The Pacific and Atlantic Oceans appear not to mix where they meet because of differences in salinity, temperature, and water density. These variations create a boundary in the water, known as a halocline or thermocline, depending on whether salt or temperature is the dominant factor. Saltier, colder water is denser and tends to sink below warmer, less salty water, preventing immediate mixing. Ocean currents, such as the powerful Gulf Stream and other regional flows, also help maintain this separ