The result of influence of temperature and salinity on
sea water density is that the ocean is layered with warm, low density water at the surface
(often called the mixed layer) and cold, high density water at
depth (deep water).
Waters of intermediate temperature and
salinity are found in the region of the thermocline and halocline.
Below you can see the distribution of water temperature
through the top 1500 meters of the ocean, which shows the great variation
in temperature in the thermocline (notice how tightly compressed the lines
of equal temperature are between 200 and 800 meters).
Used with Permission of Matthias Tomczak ©Copyright 1997
YES INDEED, THE OCEAN IS LAYERED!!!
Think of this layering as that observed in oil and vinegar
salad dressing when the two liquids separate into a layer of low density oil at the top
and higher density vinegar below, only that the ocean has many layers each with a slightly
The ocean contains many layers composed of different water
masses, each formed by a slightly different mechanism. In a general way, we can (at
least for now) group these layers into three broad categories, the (surface)
mixed layer, the thermocline layer, and the deep waters. We will subdivide the intermediate and deep layers
when we discuss the global ocean conveyor belt in the coming weeks.