In a lot of areas of the seas at middle and low latitudes, deep sea water is colder and has a lower concentration of salt than the water at the surface. Of course, the deep sea water has a higher density, and is stably stratified. If you scooped up that deep sea water and brought its temperature up to that of the surface water, its lower concentration of salt would mean it would become lighter than the surface water around it. Which means that if you stood a metal pipe upright in the sea, and pulled deep sea water into the pipe, you would end up with an automatic endless fountain.1) This phenomenon occurs as the metal pipe conducts heat from the outside, and also prevents the intrusion of salt.